@article{WaltherGuanterHeimetal.2018,
  author    = {Walther, Sophia and Guanter, Luis and Heim, Birgit and Jung, Martin and Duveiller, Gregory and Wolanin, Aleksandra and Sachs, Torsten},
  title     = {Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis},
  series = {Biogeosciences},
  volume    = {15},
  journal   = {Biogeosciences},
  number    = {20},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1726-4170},
  doi       = {10.5194/bg-15-6221-2018},
  pages     = {6221 -- 6256},
  year      = {2018},
  abstract  = {High-latitude treeless ecosystems represent spatially highly heterogeneous landscapes with small net carbon fluxes and a short growing season. Reliable observations and process understanding are critical for projections of the carbon balance of the climate-sensitive tundra. Space-borne remote sensing is the only tool to obtain spatially continuous and temporally resolved information on vegetation greenness and activity in remote circumpolar areas. However, confounding effects from persistent clouds, low sun elevation angles, numerous lakes, widespread surface inundation, and the sparseness of the vegetation render it highly challenging. Here, we conduct an extensive analysis of the timing of peak vegetation productivity as shown by satellite observations of complementary indicators of plant greenness and photosynthesis. We choose to focus on productivity during the peak of the growing season, as it importantly affects the total annual carbon uptake. The suite of indicators are as follows: (1) MODIS-based vegetation indices (VIs) as proxies for the fraction of incident photosynthetically active radiation (PAR) that is absorbed (fPAR), (2) VIs combined with estimates of PAR as a proxy of the total absorbed radiation (APAR), (3) sun-induced chlorophyll fluorescence (SIF) serving as a proxy for photosynthesis, (4) vegetation optical depth (VOD), indicative of total water content and (5) empirically upscaled modelled gross primary productivity (GPP). Averaged over the pan-Arctic we find a clear order of the annual peak as APAR <= GPP < SIF < VIs/VOD. SIF as an indicator of photosynthesis is maximised around the time of highest annual temperatures. The modelled GPP peaks at a similar time to APAR. The time lag of the annual peak between APAR and instantaneous SIF fluxes indicates that the SIF data do contain information on light-use efficiency of tundra vegetation, but further detailed studies are necessary to verify this. Delayed peak greenness compared to peak photosynthesis is consistently found across years and land-cover classes. A particularly late peak of the normalised difference vegetation index (NDVI) in regions with very small seasonality in greenness and a high amount of lakes probably originates from artefacts. Given the very short growing season in circumpolar areas, the average time difference in maximum annual photosynthetic activity and greenness or growth of 3 to 25 days (depending on the data sets chosen) is important and needs to be considered when using satellite observations as drivers in vegetation models.},
  language  = {en}
}
@article{PourteauSchererSchornetal.2019,
  author    = {Pourteau, Amaury and Scherer, Erik E. and Schorn, Simon and Bast, Rebecca and Schmidt, Alexander and Ebert, Lisa},
  title     = {Thermal evolution of an ancient subduction interface revealed by Lu-Hf garnet geochronology, Halilbagi Complex (Anatolia)},
  series = {Geoscience Frontiers},
  volume    = {10},
  journal   = {Geoscience Frontiers},
  number    = {1},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1674-9871},
  doi       = {10.1016/j.gsf.2018.03.004},
  pages     = {127 -- 148},
  year      = {2019},
  abstract  = {The thermal structure of subduction zones exerts a major influence on deep-seated mechanical and chemical processes controlling arc magmatism, seismicity, and global element cycles. Accretionary complexes exposed inland may comprise tectonic blocks with contrasting pressure-temperature (P-T) histories, making it possible to investigate the dynamics and thermal evolution of former subduction interfaces. With this aim, we present new Lu-Hf geochronological results for mafic rocks of the Halilbagi Complex (Anatolia) that evolved along different thermal gradients. Samples include a lawsonite-epidote blueschist, a lawsonite-epidote eclogite, and an epidote eclogite (all with counter-clockwise P-T paths), a prograde lawsonite blueschist with a "hairpin"-type P-T path, and a garnet amphibolite from the overlying sub-ophiolitic metamorphic sole. Equilibrium phase diagrams suggest that the garnet amphibolite formed at similar to 0.6-0.7 GPa and 800-850 degrees C, whereas the prograde lawsonite blueschist records burial from 2.1 GPa and 420 degrees C to 2.6 GPa and 520 degrees C. Well-defined Lu-Hf isochrons were obtained for the epidote eclogite (92.38 +/- 0.22 Ma) and the lawsonite-epidote blueschist (90.19 +/- 0.54 Ma), suggesting rapid garnet growth. The lawsonite-epidote eclogite (87.30 +/- 0.39 Ma) and the prograde lawsonite blueschist (ca. 86 Ma) are younger, whereas the garnet amphibolite (104.5 +/- 3.5 Ma) is older. Our data reveal a consistent trend of progressively decreasing geothermal gradient from granulite-facies conditions at similar to 104 Ma to the epidote-eclogite facies around 92 Ma, and the lawsonite blueschist-facies between 90 Ma and 86 Ma. Three Lu-Hf garnet dates (between 92 Ma and 87 Ma) weighted toward the growth of post-peak rims (as indicated by Lu distribution in garnet) suggest that the HP/LT rocks were exhumed continuously and not episodically. We infer that HP/LT metamorphic rocks within the Halilbagi Complex were subjected to continuous return flow, with "warm" rocks being exhumed during the tectonic burial of "cold" ones. Our results, combined with regional geological constraints, allow us to speculate that subduction started at a transform fault near a mid-oceanic spreading centre. Following its formation, this ancient subduction interface evolved thermally over more than 15 Myr, most likely as a result of heat dissipation rather than crustal underplating. (C) 2018, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V.},
  language  = {en}
}
@article{PaulyHelleMiramontetal.2018,
  author    = {Pauly, Maren and Helle, Gerhard and Miramont, Cecile and Buentgen, Ulf and Treydte, Kerstin and Reinig, Frederick and Guibal, Frederic and Sivan, Olivier and Heinrich, Ingo and Riedel, Frank and Kromer, Bernd and Balanzategui, Daniel and Wacker, Lukas and Sookdeo, Adam and Brauer, Achim},
  title     = {Subfossil trees suggest enhanced Mediterranean hydroclimate variability at the onset of the Younger Dryas},
  series = {Scientific reports},
  volume    = {8},
  journal   = {Scientific reports},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-018-32251-2},
  pages     = {8},
  year      = {2018},
  abstract  = {Nearly 13,000 years ago, the warming trend into the Holocene was sharply interrupted by a reversal to near glacial conditions. Climatic causes and ecological consequences of the Younger Dryas (YD) have been extensively studied, however proxy archives from the Mediterranean basin capturing this period are scarce and do not provide annual resolution. Here, we report a hydroclimatic reconstruction from stable isotopes (delta O-18, delta C-13) in subfossil pines from southern France. Growing before and during the transition period into the YD (12 900-12 600 cal BP), the trees provide an annually resolved, continuous sequence of atmospheric change. Isotopic signature of tree sourcewater (delta O-18(sw)) and estimates of relative air humidity were reconstructed as a proxy for variations in air mass origin and precipitation regime. We find a distinct increase in inter-annual variability of sourcewater isotopes (delta O-18(sw)), with three major downturn phases of increasing magnitude beginning at 12 740 cal BP. The observed variation most likely results from an amplified intensity of North Atlantic (low delta O-18(sw)) versus Mediterranean (high delta O-18(sw)) precipitation. This marked pattern of climate variability is not seen in records from higher latitudes and is likely a consequence of atmospheric circulation oscillations at the margin of the southward moving polar front.},
  language  = {en}
}
@article{HuckWohlwendCoimbraetal.2017,
  author    = {Huck, Stefan and Wohlwend, Stephan and Coimbra, Rute and Christ, Nicolas and Weissert, Helmut},
  title     = {Disentangling shallow-water bulk carbonate carbon isotope archives with evidence for multi-stage diagenesis},
  series = {The depositional record},
  volume    = {3},
  journal   = {The depositional record},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2055-4877},
  doi       = {10.1002/dep2.35},
  pages     = {233 -- 257},
  year      = {2017},
  abstract  = {Disentangling shallow-water bulk carbonate carbon isotope archives into primary and diagenetic components is a notoriously difficult task and even diagenetically screened records often provide chemostratigraphic patterns that significantly differ from global signals. This is mainly caused by the polygenetic nature of shallow-water carbonate substrates, local carbon cycle processes causing considerable neritic-pelagic isotope gradients and the presence of hiatal surfaces resulting in extremely low carbonate preservation rates. Provided here is an in-depth petrographic and geochemical evaluation of different carbonate phases of a mid-Cretaceous (Barremian-Aptian) shallow-water limestone succession (Jabal Madar section) deposited on the tropical Arabian carbonate platform in Oman. The superposition of stable isotope signatures of identified carbonate phases causes a complex and often noisy bulk carbon isotope pattern. Blocky sparite cements filling intergranular pores and bioclastic voids evidence intermediate to (arguably) deep burial diagenetic conditions during their formation, owing to different timing or differential faulting promoting the circulation of fluids from variable sources. In contrast, sparite cements filling sub-vertical veins reveal a rock-buffered diagenetic fluid composition with an intriguing moderate enrichment in 13C, probably due to fractionation during pressure release in the context of the Miocene exhumation of the carbonate platform under study. The presence of abundant, replacive dedolomite in mud-supported limestone samples forced negative carbon and oxygen isotope changes that are either associated with the thermal breakdown of organic matter in the deep burial realm or the expulsion of buried meteoric water in the intermediate burial realm. Notwithstanding the documented stratigraphically variable and often facies-related impact of different diagenetic fluids on the bulk-rock stable isotope signature, the identification of diagenetic end-members defined δ13C and δ18O threshold values that allowed the most reliable 'primary' bulk carbon isotope signatures to be extracted. Most importantly, this approach exemplifies how to place regional shallow-water stable isotope patterns with evidence for a complex multi-stage diagenetic history into a supraregional or even global context.},
  language  = {en}
}
@article{WickertSchildgen2019,
  author    = {Wickert, Andrew D. and Schildgen, Taylor F.},
  title     = {Long-profile evolution of transport-limited gravel-bed rivers},
  series = {Earth surface dynamics},
  volume    = {7},
  journal   = {Earth surface dynamics},
  number    = {1},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {2196-6311},
  doi       = {10.5194/esurf-7-17-2019},
  pages     = {17 -- 43},
  year      = {2019},
  abstract  = {Alluvial and transport-limited bedrock rivers constitute the majority of fluvial systems on Earth. Their long profiles hold clues to their present state and past evolution. We currently possess first-principles-based governing equations for flow, sediment transport, and channel morphodynamics in these systems, which we lack for detachment-limited bedrock rivers. Here we formally couple these equations for transport-limited gravel-bed river long-profile evolution. The result is a new predictive relationship whose functional form and parameters are grounded in theory and defined through experimental data. From this, we produce a power-law analytical solution and a finite-difference numerical solution to long-profile evolution. Steady-state channel concavity and steepness are diagnostic of external drivers: concavity decreases with increasing uplift rate, and steepness increases with an increasing sediment-to-water supply ratio. Constraining free parameters explains common observations of river form: to match observed channel concavities, gravel-sized sediments must weather and fine - typically rapidly - and valleys typically should widen gradually. To match the empirical square-root width-discharge scaling in equilibrium-width gravel-bed rivers, downstream fining must occur. The ability to assign a cause to such observations is the direct result of a deductive approach to developing equations for landscape evolution.},
  language  = {en}
}
@article{UberVandervaereZinetal.2018,
  author    = {Uber, Magdalena and Vandervaere, Jean-Pierre and Zin, Isabella and Braud, Isabelle and Heistermann, Maik and Legout, Cedric and Molinie, Gilles and Nord, Guillaume},
  title     = {How does initial soil moisture influence the hydrological response? A case study from southern France},
  series = {Hydrology and earth system sciences : HESS},
  volume    = {22},
  journal   = {Hydrology and earth system sciences : HESS},
  number    = {12},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1027-5606},
  doi       = {10.5194/hess-22-6127-2018},
  pages     = {6127 -- 6146},
  year      = {2018},
  abstract  = {The phi(ev) is calculated from high-resolution discharge and precipitation data for several rain events with a cumulative precipitation P-cum ranging from less than 5mm to more than 80 mm. Because of the high uncertainty of phi(ev) associated with the hydrograph separation method, phi(ev) is calculated with several methods, including graphical methods, digital filters and a tracer-based method. The results indicate that the hydrological response depends on (theta) over bar (ini): during dry conditions phi(ev) is consistently below 0.1, even for events with high and intense precipitation. Above a threshold of (theta) over bar (ini) = 34 vol \% phi(ev) can reach values up to 0.99 but there is a high scatter. Some variability can be explained with a weak correlation of phi(ev) with P-cum and rain intensity, but a considerable part of the variability remains unexplained. It is concluded that threshold-based methods can be helpful to prevent overestimation of the hydrological response during dry catchment conditions. The impact of soil moisture on the hydrological response during wet catchment conditions, however, is still insufficiently understood and cannot be generalized based on the present results.},
  language  = {en}
}
@article{KnudsenHeinoldDahlkeetal.2018,
  author    = {Knudsen, Erlend Moster and Heinold, Bernd and Dahlke, Sandro and Bozem, Heiko and Crewell, Susanne and Gorodetskaya, Irina V. and Heygster, Georg and Kunkel, Daniel and Maturilli, Marion and Mech, Mario and Viceto, Carolina and Rinke, Annette and Schmithusen, Holger and Ehrlich, Andre and Macke, Andreas and L{\"u}pkes, Christof and Wendisch, Manfred},
  title     = {Meteorological conditions during the ACLOUD/PASCAL field campaign near Svalbard in early summer 2017},
  series = {Atmospheric chemistry and physics},
  volume    = {18},
  journal   = {Atmospheric chemistry and physics},
  number    = {24},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1680-7316},
  doi       = {10.5194/acp-18-17995-2018},
  pages     = {17995 -- 18022},
  year      = {2018},
  abstract  = {The two concerted field campaigns, Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) and the Physical feedbacks of Arctic planetary boundary level Sea ice, Cloud and AerosoL (PASCAL), took place near Svalbard from 23 May to 26 June 2017. They were focused on studying Arctic mixed-phase clouds and involved observations from two airplanes (ACLOUD), an icebreaker (PASCAL) and a tethered balloon, as well as ground-based stations. Here, we present the synoptic development during the 35-day period of the campaigns, using near-surface and upper-air meteorological observations, as well as operational satellite, analysis, and reanalysis data. Over the campaign period, short-term synoptic variability was substantial, dominating over the seasonal cycle. During the first campaign week, cold and dry Arctic air from the north persisted, with a distinct but seasonally unusual cold air outbreak. Cloudy conditions with mostly low-level clouds prevailed. The subsequent 2 weeks were characterized by warm and moist maritime air from the south and east, which included two events of warm air advection. These synoptical disturbances caused lower cloud cover fractions and higher-reaching cloud systems. In the final 2 weeks, adiabatically warmed air from the west dominated, with cloud properties strongly varying within the range of the two other periods. Results presented here provide synoptic information needed to analyze and interpret data of upcoming studies from ACLOUD/PASCAL, while also offering unprecedented measurements in a sparsely observed region.},
  language  = {en}
}
@article{WeisshuhnRecklingStachowetal.2017,
  author    = {Weisshuhn, Peter and Reckling, Moritz and Stachow, Ulrich and Wiggering, Hubert},
  title     = {Supporting Agricultural Ecosystem Services through the Integration of Perennial Polycultures into Crop Rotations},
  series = {Sustainability},
  volume    = {9},
  journal   = {Sustainability},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2071-1050},
  doi       = {10.3390/su9122267},
  pages     = {20},
  year      = {2017},
  abstract  = {This review analyzes the potential role and long-term effects of field perennial polycultures (mixtures) in agricultural systems, with the aim of reducing the trade-offs between provisioning and regulating ecosystem services. First, crop rotations are identified as a suitable tool for the assessment of the long-term effects of perennial polycultures on ecosystem services, which are not visible at the single-crop level. Second, the ability of perennial polycultures to support ecosystem services when used in crop rotations is quantified through eight agricultural ecosystem services. Legume-grass mixtures and wildflower mixtures are used as examples of perennial polycultures, and compared with silage maize as a typical crop for biomass production. Perennial polycultures enhance soil fertility, soil protection, climate regulation, pollination, pest and weed control, and landscape aesthetics compared with maize. They also score lower for biomass production compared with maize, which confirms the trade-off between provisioning and regulating ecosystem services. However, the additional positive factors provided by perennial polycultures, such as reduced costs for mineral fertilizer, pesticides, and soil tillage, and a significant preceding crop effect that increases the yields of subsequent crops, should be taken into account. However, a full assessment of agricultural ecosystem services requires a more holistic analysis that is beyond the capabilities of current frameworks.},
  language  = {en}
}
@misc{WongMasonBruneetal.2019,
  author    = {Wong, Kevin and Mason, Emily and Brune, Sascha and East, Madison and Edmonds, Marie and Zahirovic, Sabin},
  title     = {Deep Carbon Cycling Over the Past 200 Million Years: A Review of Fluxes in Different Tectonic Settings},
  series = {Frontiers in Earth Science},
  volume    = {7},
  journal   = {Frontiers in Earth Science},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {2296-6463},
  doi       = {10.3389/feart.2019.00263},
  pages     = {22},
  year      = {2019},
  language  = {en}
}
@article{XiongStollePark2018,
  author    = {Xiong, Chao and Stolle, Claudia and Park, Jaeheung},
  title     = {Climatology of GPS signal loss observed by Swarm satellites},
  series = {Annales geophysicae},
  volume    = {36},
  journal   = {Annales geophysicae},
  number    = {2},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {0992-7689},
  doi       = {10.5194/angeo-36-679-2018},
  pages     = {679 -- 693},
  year      = {2018},
  abstract  = {By using 3-year global positioning system (GPS) measurements from December 2013 to November 2016, we provide in this study a detailed survey on the climatology of the GPS signal loss of Swarm onboard receivers. Our results show that the GPS signal losses prefer to occur at both low latitudes between +/- 5 and +/- 20 degrees magnetic latitude (MLAT) and high latitudes above 60 degrees MLAT in both hemispheres. These events at all latitudes are observed mainly during equinoxes and December solstice months, while totally absent during June solstice months. At low latitudes the GPS signal losses are caused by the equatorial plasma irregularities shortly after sunset, and at high latitude they are also highly related to the large density gradients associated with ionospheric irregularities. Additionally, the high-latitude events are more often observed in the Southern Hemisphere, occurring mainly at the cusp region and along nightside auroral latitudes. The signal losses mainly happen for those GPS rays with elevation angles less than 20 degrees, and more commonly occur when the line of sight between GPS and Swarm satellites is aligned with the shell structure of plasma irregularities. Our results also confirm that the capability of the Swarm receiver has been improved after the bandwidth of the phase-locked loop (PLL) widened, but the updates cannot radically avoid the interruption in tracking GPS satellites caused by the ionospheric plasma irregularities. Additionally, after the PLL bandwidth increased larger than 0.5 Hz, some unexpected signal losses are observed even at middle latitudes, which are not related to the ionospheric plasma irregularities. Our results suggest that rather than 1.0 Hz, a PLL bandwidth of 0.5 Hz is a more suitable value for the Swarm receiver.},
  language  = {en}
}
@article{LaraNitzeGrosseetal.2018,
  author    = {Lara, Mark J. and Nitze, Ingmar and Grosse, Guido and Martin, Philip and McGuire, A. David},
  title     = {Reduced arctic tundra productivity linked with landform and climate change interactions},
  series = {Scientific reports},
  volume    = {8},
  journal   = {Scientific reports},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-018-20692-8},
  pages     = {10},
  year      = {2018},
  abstract  = {Arctic tundra ecosystems have experienced unprecedented change associated with climate warming over recent decades. Across the Pan-Arctic, vegetation productivity and surface greenness have trended positively over the period of satellite observation. However, since 2011 these trends have slowed considerably, showing signs of browning in many regions. It is unclear what factors are driving this change and which regions/landforms will be most sensitive to future browning. Here we provide evidence linking decadal patterns in arctic greening and browning with regional climate change and local permafrost-driven landscape heterogeneity. We analyzed the spatial variability of decadal-scale trends in surface greenness across the Arctic Coastal Plain of northern Alaska (similar to 60,000 km(2)) using the Landsat archive (1999-2014), in combination with novel 30 m classifications of polygonal tundra and regional watersheds, finding landscape heterogeneity and regional climate change to be the most important factors controlling historical greenness trends. Browning was linked to increased temperature and precipitation, with the exception of young landforms (developed following lake drainage), which will likely continue to green. Spatiotemporal model forecasting suggests carbon uptake potential to be reduced in response to warmer and/or wetter climatic conditions, potentially increasing the net loss of carbon to the atmosphere, at a greater degree than previously expected.},
  language  = {en}
}
@article{GoodwinMuddClubb2018,
  author    = {Goodwin, Guillaume C. H. and Mudd, Simon M. and Clubb, Fiona J.},
  title     = {Unsupervised detection of salt marsh platforms},
  series = {Earth surface dynamics},
  volume    = {6},
  journal   = {Earth surface dynamics},
  number    = {1},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {2196-6311},
  doi       = {10.5194/esurf-6-239-2018},
  pages     = {239 -- 255},
  year      = {2018},
  abstract  = {Salt marshes filter pollutants, protect coastlines against storm surges, and sequester carbon, yet are under threat from sea level rise and anthropogenic modification. The sustained existence of the salt marsh ecosystem depends on the topographic evolution of marsh platforms. Quantifying marsh platform topography is vital for improving the management of these valuable landscapes. The determination of platform boundaries currently relies on supervised classification methods requiring near-infrared data to detect vegetation, or demands labour-intensive field surveys and digitisation. We propose a novel, unsupervised method to reproducibly isolate salt marsh scarps and platforms from a digital elevation model (DEM), referred to as Topographic Identification of Platforms (TIP). Field observations and numerical models show that salt marshes mature into subhorizontal platforms delineated by subvertical scarps. Based on this premise, we identify scarps as lines of local maxima on a slope raster, then fill landmasses from the scarps upward, thus isolating mature marsh platforms. We test the TIP method using lidar-derived DEMs from six salt marshes in England with varying tidal ranges and geometries, for which topographic platforms were manually isolated from tidal flats. Agreement between manual and unsupervised classification exceeds 94\% for DEM resolutions of 1 m, with all but one site maintaining an accuracy superior to 90\% for resolutions up to 3 m. For resolutions of 1 m, platforms detected with the TIP method are comparable in surface area to digitised platforms and have similar elevation distributions. We also find that our method allows for the accurate detection of local block failures as small as 3 times the DEM resolution. Detailed inspection reveals that although tidal creeks were digitised as part of the marsh platform, unsupervised classification categorises them as part of the tidal flat, causing an increase in false negatives and overall platform perimeter. This suggests our method may benefit from combination with existing creek detection algorithms. Fallen blocks and high tidal flat portions, associated with potential pioneer zones, can also lead to differences between our method and supervised mapping. Although pioneer zones prove difficult to classify using a topographic method, we suggest that these transition areas should be considered when analysing erosion and accretion processes, particularly in the case of incipient marsh platforms. Ultimately, we have shown that unsupervised classification of marsh platforms from high-resolution topography is possible and sufficient to monitor and analyse topographic evolution.},
  language  = {en}
}
@article{FuchsGrosseStraussetal.2018,
  author    = {Fuchs, Matthias and Grosse, Guido and Strauss, Jens and G{\"u}nther, Frank and Grigoriev, Mikhail N. and Maximov, Georgy M. and Hugelius, Gustaf},
  title     = {Carbon and nitrogen pools in thermokarst-affected permafrost landscapes in Arctic Siberia},
  series = {Biogeosciences},
  volume    = {15},
  journal   = {Biogeosciences},
  number    = {3},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1726-4170},
  doi       = {10.5194/bg-15-953-2018},
  pages     = {953 -- 971},
  year      = {2018},
  abstract  = {Ice-rich yedoma-dominated landscapes store considerable amounts of organic carbon (C) and nitrogen (N) and are vulnerable to degradation under climate warming. We investigate the C and N pools in two thermokarst-affected yedoma landscapes - on Sobo-Sise Island and on Bykovsky Peninsula in the north of eastern Siberia. Soil cores up to 3m depth were collected along geomorphic gradients and analysed for organic C and N contents. A high vertical sampling density in the profiles allowed the calculation of C and N stocks for short soil column intervals and enhanced understanding of within-core parameter variability. Profile-level C and N stocks were scaled to the landscape level based on landform classifications from 5 m resolution, multispectral RapidEye satellite imagery. Mean landscape C and N storage in the first metre of soil for Sobo-Sise Island is estimated to be 20.2 kg C m(-2) and 1.8 kg N m(-2) and for Bykovsky Peninsula 25.9 kg C m(-2) and 2.2 kg N m(-2). Radiocarbon dating demonstrates the Holocene age of thermokarst basin deposits but also suggests the presence of thick Holoceneage cover layers which can reach up to 2 m on top of intact yedoma landforms. Reconstructed sedimentation rates of 0.10-0.57 mm yr(-1) suggest sustained mineral soil accumulation across all investigated landforms. Both yedoma and thermokarst landforms are characterized by limited accumulation of organic soil layers (peat). We further estimate that an active layer deepening of about 100 cm will increase organic C availability in a seasonally thawed state in the two study areas by similar to 5.8 Tg (13.2 kg C m(-2)). Our study demonstrates the importance of increasing the number of C and N storage inventories in ice-rich yedoma and thermokarst environments in order to account for high variability of permafrost and thermokarst environments in pan-permafrost soil C and N pool estimates.},
  language  = {en}
}
@article{TaffarelloSrinivasanSamprognaMohoretal.2018,
  author    = {Taffarello, Denise and Srinivasan, Raghavan and Samprogna Mohor, Guilherme and Bittencourt Guimaraes, Joao Luis and Calijuri, Maria do Carmo and Mendiondo, Eduardo Mario},
  title     = {Modeling freshwater quality scenarios with ecosystem-based adaptation in the headwaters of the Cantareira system, Brazil},
  series = {Hydrology and earth system sciences : HESS},
  volume    = {22},
  journal   = {Hydrology and earth system sciences : HESS},
  number    = {9},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1027-5606},
  doi       = {10.5194/hess-22-4699-2018},
  pages     = {4699 -- 4723},
  year      = {2018},
  abstract  = {Although hydrologic models provide hypothesis testing of complex dynamics occurring at catchments, fresh-water quality modeling is still incipient at many subtropical headwaters. In Brazil, a few modeling studies assess freshwater nutrients, limiting policies on hydrologic ecosystem services. This paper aims to compare freshwater quality scenarios under different land-use and land-cover (LULC) change, one of them related to ecosystem-based adaptation (EbA), in Brazilian headwaters. Using the spatially semi-distributed Soil and Water Assessment Tool (SWAT) model, nitrate, total phosphorous (TP) and sediment were modeled in catchments ranging from 7.2 to 1037 km(2). These head-waters were eligible areas of the Brazilian payment for ecosystem services (PES) projects in the Cantareira water supply system, which had supplied water to 9 million people in the Sao Paulo metropolitan region (SPMR). We considered SWAT modeling of three LULC scenarios: (i) recent past scenario (S1), with historical LULC in 1990; (ii) current land-use scenario (S2), with LULC for the period 2010-2015 with field validation; and (iii) future land-use scenario with PES (S2 + EbA). This latter scenario proposed forest cover restoration through EbA following the river basin plan by 2035. These three LULC scenarios were tested with a selected record of rainfall and evapotranspiration observed in 2006-2014, with the occurrence of extreme droughts. To assess hydrologic services, we proposed the hydrologic service index (HSI), as a new composite metric comparing water pollution levels (WPL) for reference catchments, related to the grey water footprint (greyWF) and water yield. On the one hand, water quality simulations allowed for the regionalization of greyWF at spatial scales under LULC scenarios. According to the critical threshold, HSI identified areas as less or more sustainable catchments. On the other hand, conservation practices simulated through the S2 + EbA scenario envisaged not only additional and viable best management practices (BMP), but also preventive decision-making at the headwaters of water supply systems.},
  language  = {en}
}
@article{MarciszJasseyKosakyanetal.2020,
  author    = {Marcisz, Katarzyna and Jassey, Vincent E. J. and Kosakyan, Anush and Krashevska, Valentyna and Lahr, Daniel J. G. and Lara, Enrique and Lamentowicz, Lukasz and Lamentowicz, Mariusz and Macumber, Andrew and Mazei, Yuri and Mitchell, Edward A. D. and Nasser, Nawaf A. and Patterson, R. Timothy and Roe, Helen M. and Singer, David and Tsyganov, Andrey N. and Fournier, Bertrand},
  title     = {Testate amoeba functional traits and their use in paleoecology},
  series = {Frontiers in Ecology and Evolution},
  volume    = {8},
  journal   = {Frontiers in Ecology and Evolution},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {2296-701X},
  doi       = {10.3389/fevo.2020.575966},
  pages     = {28},
  year      = {2020},
  abstract  = {This review provides a synthesis of current knowledge on the morphological and functional traits of testate amoebae, a polyphyletic group of protists commonly used as proxies of past hydrological changes in paleoecological investigations from peatland, lake sediment and soil archives. A trait-based approach to understanding testate amoebae ecology and paleoecology has gained in popularity in recent years, with research showing that morphological characteristics provide complementary information to the commonly used environmental inferences based on testate amoeba (morpho-)species data. We provide a broad overview of testate amoeba morphological and functional traits and trait-environment relationships in the context of ecology, evolution, genetics, biogeography, and paleoecology. As examples we report upon previous ecological and paleoecological studies that used trait-based approaches, and describe key testate amoebae traits that can be used to improve the interpretation of environmental studies. We also highlight knowledge gaps and speculate on potential future directions for the application of trait-based approaches in testate amoeba research.},
  language  = {en}
}
@article{MuldashevSobolev2020,
  author    = {Muldashev, Iskander A. and Sobolev, Stephan},
  title     = {What controls maximum magnitudes of giant subduction earthquakes?},
  series = {Geochemistry, geophysics, geosystems},
  volume    = {21},
  journal   = {Geochemistry, geophysics, geosystems},
  number    = {9},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {1525-2027},
  doi       = {10.1029/2020GC009145},
  pages     = {15},
  year      = {2020},
  abstract  = {Giant earthquakes with magnitudes above 8.5 occur only in subduction zones. Despite the developments made in observing large subduction zone earthquakes with geophysical instruments, the factors controlling the maximum size of these earthquakes are still poorly understood. Previous studies have suggested the importance of slab shape, roughness of the plate interface contact, state of the strain in the upper plate, thickness of sediments filling the trenches, and subduction rate. Here, we present 2-D cross-scale numerical models of seismic cycles for subduction zones with various geometries, subduction channel friction configurations, and subduction rates. We found that low-angle subduction and thick sediments in the subduction channel are the necessary conditions for generating giant earthquakes, while the subduction rate has a negligible effect. We suggest that these key parameters determine the maximum magnitude of a subduction earthquake by controlling the seismogenic zone width and smoothness of the subduction interface. This interpretation supports previous studies that are based upon observations and scaling laws. Our modeling results also suggest that low static friction in the sediment-filled subduction channel results in neutral or moderate compressive deformation in the overriding plate for low-angle subduction zones hosting giant earthquakes. These modeling results agree well with observations for the largest earthquakes. Based on our models we predict maximum magnitudes of subduction earthquakes worldwide, demonstrating the fit to magnitudes of all giant earthquakes of the 20th and 21st centuries and good agreement with the predictions based on statistical analyses of observations.},
  language  = {en}
}
@article{TutuSteinbergerSobolevetal.2018,
  author    = {Tutu, Anthony Osei and Steinberger, Bernhard and Sobolev, Stephan Vladimir and Rogozhina, Irina and Popov, Anton A.},
  title     = {Effects of upper mantle heterogeneities on the lithospheric stress field and dynamic topography},
  series = {Solid earth},
  volume    = {9},
  journal   = {Solid earth},
  number    = {3},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1869-9510},
  doi       = {10.5194/se-9-649-2018},
  pages     = {649 -- 668},
  year      = {2018},
  abstract  = {The orientation and tectonic regime of the observed crustal/lithospheric stress field contribute to our knowledge of different deformation processes occurring within the Earth's crust and lithosphere. In this study, we analyze the influence of the thermal and density structure of the upper mantle on the lithospheric stress field and topography. We use a 3-D lithosphere-asthenosphere numerical model with power-law rheology, coupled to a spectral mantle flow code at 300 km depth. Our results are validated against the World Stress Map 2016 (WSM2016) and the observation-based residual topography. We derive the upper mantle thermal structure from either a heat flow model combined with a seafloor age model (TM1) or a global S-wave velocity model (TM2). We show that lateral density heterogeneities in the upper 300 km have a limited influence on the modeled horizontal stress field as opposed to the resulting dynamic topography that appears more sensitive to such heterogeneities. The modeled stress field directions, using only the mantle heterogeneities below 300 km, are not perturbed much when the effects of lithosphere and crust above 300 km are added. In contrast, modeled stress magnitudes and dynamic topography are to a greater extent controlled by the upper mantle density structure. After correction for the chemical depletion of continents, the TM2 model leads to a much better fit with the observed residual topography giving a good correlation of 0.51 in continents, but this correction leads to no significant improvement of the fit between the WSM2016 and the resulting lithosphere stresses. In continental regions with abundant heat flow data, TM1 results in relatively small angular misfits. For example, in western Europe the misfit between the modeled and observation-based stress is 18.3°. Our findings emphasize that the relative contributions coming from shallow and deep mantle dynamic forces are quite different for the lithospheric stress field and dynamic topography.},
  language  = {en}
}
@article{EhrlichGaedke2018,
  author    = {Ehrlich, Elias and Gaedke, Ursula},
  title     = {Not attackable or not crackable},
  series = {Ecology and evolution},
  volume    = {8},
  journal   = {Ecology and evolution},
  number    = {13},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2045-7758},
  doi       = {10.1002/ece3.4145},
  pages     = {6625 -- 6637},
  year      = {2018},
  abstract  = {It is well-known that prey species often face trade-offs between defense against predation and competitiveness, enabling predator-mediated coexistence. However, we lack an understanding of how the large variety of different defense traits with different competition costs affects coexistence and population dynamics. Our study focusses on two general defense mechanisms, that is, pre-attack (e.g., camouflage) and post-attack defenses (e.g., weaponry) that act at different phases of the predator—prey interaction. We consider a food web model with one predator, two prey types and one resource. One prey type is undefended, while the other one is pre- or post-attack defended paying costs either by a higher half-saturation constant for resource uptake or a lower maximum growth rate. We show that post-attack defenses promote prey coexistence and stabilize the population dynamics more strongly than pre-attack defenses by interfering with the predator's functional response: Because the predator spends time handling "noncrackable" prey, the undefended prey is indirectly facilitated. A high half-saturation constant as defense costs promotes coexistence more and stabilizes the dynamics less than a low maximum growth rate. The former imposes high costs at low resource concentrations but allows for temporally high growth rates at predator-induced resource peaks preventing the extinction of the defended prey. We evaluate the effects of the different defense mechanisms and costs on coexistence under different enrichment levels in order to vary the importance of bottom-up and top-down control of the prey community.},
  language  = {en}
}
@article{FilipovicGerkeFilipovicetal.2018,
  author    = {Filipovic, Vilim and Gerke, Horst H. and Filipovic, Lana and Sommer, Michael},
  title     = {Quantifying subsurface lateral flow along sloping horizon boundaries in soil profiles of a hummocky ground moraine},
  series = {Vadose zone journal},
  volume    = {17},
  journal   = {Vadose zone journal},
  number    = {1},
  publisher = {Soil Science Society of America},
  address   = {Madison},
  issn      = {1539-1663},
  doi       = {10.2136/vzj2017.05.0106},
  pages     = {12},
  year      = {2018},
  abstract  = {Subsurface lateral flow in hillslope soils depends on lower permeability or texture-contrasting soil horizons. In the arable hummocky soil landscape, erosion processes caused glacial till appearance closer to the soil surface at upslope positions. The objective of this work was to quantify the potential for subsurface lateral flow depending on the erosion-affected spatial hydropedological complexity. The eroded Haplic Luvisol profile was studied due to the presence of a relatively dense C horizon that varied in depth, thickness, and sloping angle. A two-dimensional numerical modeling and sensitivity analysis for the saturated hydraulic conductivity (K-s) of the C horizon and the depth to C horizon (i.e., soil solum thickness) was performed for rainstorms in 2011 and 2012 using HYDRUS-2D. A K-s value of <2.5 cm d(-1) for the C horizon was required for lateral flow initiation. Lateral flow was (i) increasing with decreasing solum thickness, indicating an erosion-induced feedback on subsurface lateral flow, and (ii) dependent on the soil moisture regime prior to rainstorms. The effect of lateral flow on the movement of a conservative tracer was simulated in the form of a "virtual experiment". Simulation scenarios revealed only a relatively small lateral shift of the tracer plume caused by a local decoupling of water (already lateral) from subsequent tracer movement (still vertical). Longer term simulations suggested that, for the present conditions, lateral flow was limited mostly to occasional summer storm events. Even without considering preferential flow contribution to lateral flow, highly complex hydropedologic interactions are present in erosion-affected heterogeneous soil profiles.},
  language  = {en}
}
@article{CasadoLandaisPicardetal.2018,
  author    = {Casado, Mathieu and Landais, Amaelle and Picard, Ghislain and M{\"u}nch, Thomas and Laepple, Thomas and Stenni, Barbara and Dreossi, Giuliano and Ekaykin, Alexey and Arnaud, Laurent and Genthon, Christophe and Touzeau, Alexandra and Masson-Delmotte, Valerie and Jouzel, Jean},
  title     = {Archival processes of the water stable isotope signal in East Antarctic ice cores},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {12},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {5},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-12-1745-2018},
  pages     = {1745 -- 1766},
  year      = {2018},
  abstract  = {The oldest ice core records are obtained from the East Antarctic Plateau. Water isotopes are key proxies to reconstructing past climatic conditions over the ice sheet and at the evaporation source. The accuracy of climate reconstructions depends on knowledge of all processes affecting water vapour, precipitation and snow isotopic compositions. Fractionation processes are well understood and can be integrated in trajectory-based Rayleigh distillation and isotope-enabled climate models. However, a quantitative understanding of processes potentially altering snow isotopic composition after deposition is still missing. In low-accumulation sites, such as those found in East Antarctica, these poorly constrained processes are likely to play a significant role and limit the interpretability of an ice core's isotopic composition. By combining observations of isotopic composition in vapour, precipitation, surface snow and buried snow from Dome C, a deep ice core site on the East Antarctic Plateau, we found indications of a seasonal impact of metamorphism on the surface snow isotopic signal when compared to the initial precipitation. Particularly in summer, exchanges of water molecules between vapour and snow are driven by the diurnal sublimation-condensation cycles. Overall, we observe in between precipitation events modification of the surface snow isotopic composition. Using high-resolution water isotopic composition profiles from snow pits at five Antarctic sites with different accumulation rates, we identified common patterns which cannot be attributed to the seasonal variability of precipitation. These differences in the precipitation, surface snow and buried snow isotopic composition provide evidence of post-deposition processes affecting ice core records in low-accumulation areas.},
  language  = {en}
}
@article{LehrDannowskiKalettkaetal.2018,
  author    = {Lehr, Christian and Dannowski, Ralf and Kalettka, Thomas and Merz, Christoph and Schr{\"o}der, Boris and Steidl, J{\"o}rg and Lischeid, Gunnar},
  title     = {Detecting dominant changes in irregularly sampled multivariate water quality data sets},
  series = {Hydrology and earth system sciences : HESS},
  volume    = {22},
  journal   = {Hydrology and earth system sciences : HESS},
  number    = {8},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1027-5606},
  doi       = {10.5194/hess-22-4401-2018},
  pages     = {4401 -- 4424},
  year      = {2018},
  abstract  = {Time series of groundwater and stream water quality often exhibit substantial temporal and spatial variability, whereas typical existing monitoring data sets, e.g. from environmental agencies, are usually characterized by relatively low sampling frequency and irregular sampling in space and/or time. This complicates the differentiation between anthropogenic influence and natural variability as well as the detection of changes in water quality which indicate changes in single drivers. We suggest the new term "dominant changes" for changes in multivariate water quality data which concern (1) multiple variables, (2) multiple sites and (3) long-term patterns and present an exploratory framework for the detection of such dominant changes in data sets with irregular sampling in space and time. Firstly, a non-linear dimension-reduction technique was used to summarize the dominant spatiotemporal dynamics in the multivariate water quality data set in a few components. Those were used to derive hypotheses on the dominant drivers influencing water quality. Secondly, different sampling sites were compared with respect to median component values. Thirdly, time series of the components at single sites were analysed for long-term patterns. We tested the approach with a joint stream water and groundwater data set quality consisting of 1572 samples, each comprising sixteen variables, sampled with a spatially and temporally irregular sampling scheme at 29 sites in northeast Germany from 1998 to 2009. The first four components were interpreted as (1) an agriculturally induced enhancement of the natural background level of solute concentration, (2) a redox sequence from reducing conditions in deep groundwater to post-oxic conditions in shallow groundwater and oxic conditions in stream water, (3) a mixing ratio of deep and shallow groundwater to the streamflow and (4) sporadic events of slurry application in the agricultural practice. Dominant changes were observed for the first two components. The changing intensity of the first component was interpreted as response to the temporal variability of the thickness of the unsaturated zone. A steady increase in the second component at most stream water sites pointed towards progressing depletion of the denitrification capacity of the deep aquifer.},
  language  = {en}
}
@article{BruneWilliamsMueller2018,
  author    = {Brune, Sascha and Williams, Simon E. and M{\"u}ller, R. Dietmar},
  title     = {Oblique rifting: the rule, not the exception},
  series = {Solid earth},
  volume    = {9},
  journal   = {Solid earth},
  number    = {5},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1869-9510},
  doi       = {10.5194/se-9-1187-2018},
  pages     = {1187 -- 1206},
  year      = {2018},
  abstract  = {Movements of tectonic plates often induce oblique deformation at divergent plate boundaries. This is in striking contrast with traditional conceptual models of rifting and rifted margin formation, which often assume 2-D deformation where the rift velocity is oriented perpendicular to the plate boundary. Here we quantify the validity of this assumption by analysing the kinematics of major continent-scale rift systems in a global plate tectonic reconstruction from the onset of Pangea breakup until the present day. We evaluate rift obliquity by joint examination of relative extension velocity and local rift trend using the script-based plate reconstruction software pyGPlates. Our results show that the global mean rift obliquity since 230 Ma amounts to 34 degrees with a standard deviation of 24 degrees, using the convention that the angle of obliquity is spanned by extension direction and rift trend normal. We find that more than similar to 70 \% of all rift segments exceeded an obliquity of 20 degrees demonstrating that oblique rifting should be considered the rule, not the exception. In many cases, rift obliquity and extension velocity increase during rift evolution (e.g. Australia-Antarctica, Gulf of California, South Atlantic, India-Antarctica), which suggests an underlying geodynamic correlation via obliquity-dependent rift strength. Oblique rifting produces 3-D stress and strain fields that cannot be accounted for in simplified 2-D plane strain analysis. We therefore highlight the importance of 3-D approaches in modelling, surveying, and interpretation of most rift segments on Earth where oblique rifting is the dominant mode of deformation.},
  language  = {en}
}
@article{CoesfeldAndersonBaughetal.2018,
  author    = {Coesfeld, Jacqueline and Anderson, Sharolyn J. and Baugh, Kimberly and Elvidge, Christopher D. and Schernthanner, Harald and Kyba, Christopher C. M.},
  title     = {Variation of Individual Location Radiance in VIIRS DNB Monthly Composite Images},
  series = {Remote sensing},
  volume    = {10},
  journal   = {Remote sensing},
  number    = {12},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2072-4292},
  doi       = {10.3390/rs10121964},
  pages     = {17},
  year      = {2018},
  abstract  = {With the growing size and use of night light time series from the Visible Infrared Imaging Radiometer Suite Day/Night Band (DNB), it is important to understand the stability of the dataset. All satellites observe differences in pixel values during repeat observations. In the case of night light data, these changes can be due to both environmental effects and changes in light emission. Here we examine the stability of individual locations of particular large scale light sources (e.g., airports and prisons) in the monthly composites of DNB data from April 2012 to September 2017. The radiances for individual pixels of most large light emitters are approximately normally distributed, with a standard deviation of typically 15-20\% of the mean. Greenhouses and flares, however, are not stable sources. We observe geospatial autocorrelation in the monthly variations for nearby sites, while the correlation for sites separated by large distances is small. This suggests that local factors contribute most to the variation in the pixel radiances and furthermore that averaging radiances over large areas will reduce the total variation. A better understanding of the causes of temporal variation would improve the sensitivity of DNB to lighting changes.},
  language  = {en}
}
@article{LatimerJacobsGianolietal.2019,
  author    = {Latimer, Andrew M. and Jacobs, Brooke S. and Gianoli, Ernesto and Heger, Tina and Salgado-Luarte, Cristian},
  title     = {Parallel functional differentiation of an invasive annual plant on two continents},
  series = {AoB PLANTS},
  volume    = {11},
  journal   = {AoB PLANTS},
  number    = {2},
  publisher = {Oxford University Press},
  address   = {Oxford},
  issn      = {2041-2851},
  doi       = {10.1093/aobpla/plz010},
  pages     = {16},
  year      = {2019},
  abstract  = {Rapid local adaptation frequently occurs during the spread of invading species. It remains unclear, however, how consistent, and therefore potentially predictable, such patterns of local adaptation are. One approach to this question is to measure patterns of local differentiation in functional traits and plasticity levels in invasive species in multiple regions. Finding consistent patterns of local differentiation in replicate regions suggests that these patterns are adaptive. Further, this outcome indicates that the invading species likely responds predictably to selection along environmental gradients, even though standing genetic variation is likely to have been reduced during introduction. We studied local differentiation in the invasive annual plant Erodium cicutarium in two invaded regions, California and Chile. We collected seeds from across strong gradients in precipitation and temperature in Mediterranean-climate parts of the two regions (10 populations per region). We grew seeds from maternal families from these populations through two generations and exposed the second generation to contrasting levels of water and nutrient availability. We measured growth, flowering time and leaf functional traits across these treatments to obtain trait means and plasticity measures. We found strong differentiation among populations in all traits. Plants from drier environments flowered earlier, were less plastic in flowering time and reached greater size in all treatments. Correlations among traits within regions suggested a coordinated evolutionary response along environmental gradients associated with growing season length. There was little divergence in traits and trait intercorrelations between regions, but strongly parallel divergence in traits within regions. Similar, statistically consistent patterns of local trait differentiation across two regions suggest that local adaptation to environmental gradients has aided the spread of this invasive species, and that the formation of ecotypes in newly invaded environments has been relatively consistent and predictable.},
  language  = {en}
}
@article{JavharChenBaoetal.2019,
  author    = {Javhar, Aminov and Chen, Xi and Bao, Anming and Jamshed, Aminov and Yunus, Mamadjanov and Jovid, Aminov and Latipa, Tuerhanjiang},
  title     = {Comparison of Multi-Resolution Optical Landsat-8, Sentinel-2 and Radar Sentinel-1 Data for Automatic Lineament Extraction},
  series = {Remote sensing},
  volume    = {11},
  journal   = {Remote sensing},
  number    = {7},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2072-4292},
  doi       = {10.3390/rs11070778},
  pages     = {29},
  year      = {2019},
  abstract  = {Lineament mapping, which is an important part of any structural geological investigation, is made more efficient and easier by the availability of optical as well as radar remote sensing data, such as Landsat and Sentinel with medium and high spatial resolutions. However, the results from these multi-resolution data vary due to their difference in spatial resolution and sensitivity to soil occupation. The accuracy and quality of extracted lineaments depend strongly on the spatial resolution of the imagery. Therefore, the aim of this study was to compare the optical Landsat-8, Sentinel-2A, and radar Sentinel-1A satellite data for automatic lineament extraction. The framework of automatic approach includes defining the optimal parameters for automatic lineament extraction with a combination of edge detection and line-linking algorithms and determining suitable bands from optical data suited for lineament mapping in the study area. For the result validation, the extracted lineaments are compared against the manually obtained lineaments through the application of directional filtering and edge enhancement as well as to the lineaments digitized from the existing geological maps of the study area. In addition, a digital elevation model (DEM) has been utilized for an accuracy assessment followed by the field verification. The obtained results show that the best correlation between automatically extracted lineaments, manual interpretation, and the preexisting lineament map is achieved from the radar Sentinel-1A images. The tests indicate that the radar data used in this study, with 5872 and 5865 lineaments extracted from VH and VV polarizations respectively, is more efficient for structural lineament mapping than the Landsat-8 and Sentinel-2A optical imagery, from which 2338 and 4745 lineaments were extracted respectively.},
  language  = {en}
}
@misc{HargisGotschPoradaetal.2019,
  author    = {Hargis, Hailey and Gotsch, Sybil G. and Porada, Philipp and Moore, Georgianne W. and Ferguson, Briana and Van Stan, John T.},
  title     = {Arboreal epiphytes in the soil-atmosphere interface},
  series = {Geosciences},
  volume    = {9},
  journal   = {Geosciences},
  number    = {8},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2076-3263},
  doi       = {10.3390/geosciences9080342},
  pages     = {17},
  year      = {2019},
  abstract  = {Arboreal epiphytes (plants residing in forest canopies) are present across all major climate zones and play important roles in forest biogeochemistry. The substantial water storage capacity per unit area of the epiphyte "bucket" is a key attribute underlying their capability to influence forest hydrological processes and their related mass and energy flows. It is commonly assumed that the epiphyte bucket remains saturated, or near-saturated, most of the time; thus, epiphytes (particularly vascular epiphytes) can store little precipitation, limiting their impact on the forest canopy water budget. We present evidence that contradicts this common assumption from (i) an examination of past research; (ii) new datasets on vascular epiphyte and epi-soil water relations at a tropical montane cloud forest (Monteverde, Costa Rica); and (iii) a global evaluation of non-vascular epiphyte saturation state using a process-based vegetation model, LiBry. All analyses found that the external and internal water storage capacity of epiphyte communities is highly dynamic and frequently available to intercept precipitation. Globally, non-vascular epiphytes spend <20\% of their time near saturation and regionally, including the humid tropics, model results found that non-vascular epiphytes spend similar to 1/3 of their time in the dry state (0-10\% of water storage capacity). Even data from Costa Rican cloud forest sites found the epiphyte community was saturated only 1/3 of the time and that internal leaf water storage was temporally dynamic enough to aid in precipitation interception. Analysis of the epi-soils associated with epiphytes further revealed the extent to which the epiphyte bucket emptied-as even the canopy soils were often <50\% saturated (29-53\% of all days observed). Results clearly show that the epiphyte bucket is more dynamic than currently assumed, meriting further research on epiphyte roles in precipitation interception, redistribution to the surface and chemical composition of "net" precipitation waters reaching the surface.},
  language  = {en}
}
@article{CordonnierBovyBraun2019,
  author    = {Cordonnier, Guillaume and Bovy, Benoit and Braun, Jean},
  title     = {A versatile, linear complexity algorithm for flow routing in topographies with depressions},
  series = {Earth surface dynamics},
  volume    = {7},
  journal   = {Earth surface dynamics},
  number    = {2},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {2196-6311},
  doi       = {10.5194/esurf-7-549-2019},
  pages     = {549 -- 562},
  year      = {2019},
  abstract  = {We present a new algorithm for solving the common problem of flow trapped in closed depressions within digital elevation models, as encountered in many applications relying on flow routing. Unlike other approaches (e.g., the Priority-Flood depression filling algorithm), this solution is based on the explicit computation of the flow paths both within and across the depressions through the construction of a graph connecting together all adjacent drainage basins. Although this represents many operations, a linear time complexity can be reached for the whole computation, making it very efficient. Compared to the most optimized solutions proposed so far, we show that this algorithm of flow path enforcement yields the best performance when used in landscape evolution models. In addition to its efficiency, our proposed method also has the advantage of letting the user choose among different strategies of flow path enforcement within the depressions (i.e., filling vs. carving). Furthermore, the computed graph of basins is a generic structure that has the potential to be reused for solving other problems as well, such as the simulation of erosion. This sequential algorithm may be helpful for those who need to, e.g., process digital elevation models of moderate size on single computers or run batches of simulations as part of an inference study.},
  language  = {en}
}
@article{MassonBambergStrickeretal.2019,
  author    = {Masson, Torsten and Bamberg, Sebastian and Stricker, Michael and Heidenreich, Anna},
  title     = {"We can help ourselves": does community resilience buffer against the negative impact of flooding on mental health?},
  series = {Natural hazards and earth system sciences},
  volume    = {19},
  journal   = {Natural hazards and earth system sciences},
  number    = {11},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1561-8633},
  doi       = {10.5194/nhess-19-2371-2019},
  pages     = {2371 -- 2384},
  year      = {2019},
  abstract  = {Empirical evidence of the relationship between social support and post-disaster mental health provides support for a general beneficial effect of social support (main-effect model; Wheaton, 1985). From a theoretical perspective, a buffering effect of social support on the negative relationship between disaster-related stress and mental health also seems plausible (stress-buffering model; Wheaton, 1985). Previous studies, however, (a) have paid less attention to the buffering effect of social support and (b) have mainly relied on interpersonal support (but not collective-level support such as community resilience) when investigating this issue. This previous work might have underestimated the effect of support on post-disaster mental health. Building on a sample of residents in Germany recently affected by flooding (N = 118), we show that community resilience to flooding (but not general interpersonal social support) buffered against the negative effects of flooding on post-disaster mental health. The results support the stress-buffering model and call for a more detailed look at the relationship between support and resilience and post-disaster adjustment, including collective-level variables.},
  language  = {en}
}
@misc{AyzelIzhitskiy2018,
  author    = {Ayzel, Georgy and Izhitskiy, Alexander},
  title     = {Coupling physically based and data-driven models for assessing freshwater inflow into the Small Aral Sea},
  series = {Innovative Water Resources Management in a Changing Environment - Understanding and Balancing Interactions between Humankind and Nature},
  volume    = {379},
  journal   = {Innovative Water Resources Management in a Changing Environment - Understanding and Balancing Interactions between Humankind and Nature},
  editor    = {Xu, Z Peng},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {2199-899X},
  doi       = {10.5194/piahs-379-151-2018},
  pages     = {151 -- 158},
  year      = {2018},
  abstract  = {The Aral Sea desiccation and related changes in hydroclimatic conditions on a regional level is a hot topic for past decades. The key problem of scientific research projects devoted to an investigation of modern Aral Sea basin hydrological regime is its discontinuous nature - the only limited amount of papers takes into account the complex runoff formation system entirely. Addressing this challenge we have developed a continuous prediction system for assessing freshwater inflow into the Small Aral Sea based on coupling stack of hydrological and data-driven models. Results show a good prediction skill and approve the possibility to develop a valuable water assessment tool which utilizes the power of classical physically based and modern machine learning models both for territories with complex water management system and strong water-related data scarcity. The source code and data of the proposed system is available on a Github page (https://github.com/SMASHIproject/IWRM2018).},
  language  = {en}
}
@article{TotzPetriLehmannetal.2019,
  author    = {Totz, Sonja Juliana and Petri, Stefan and Lehmann, Jascha and Peukert, Erik and Coumou, Dim},
  title     = {Exploring the sensitivity of Northern Hemisphere atmospheric circulation to different surface temperature forcing using a statistical-dynamical atmospheric model},
  series = {Nonlinear processes in geophysics},
  volume    = {26},
  journal   = {Nonlinear processes in geophysics},
  number    = {1},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1023-5809},
  doi       = {10.5194/npg-26-1-2019},
  pages     = {1 -- 12},
  year      = {2019},
  abstract  = {Climate and weather conditions in the mid-latitudes are strongly driven by the large-scale atmosphere circulation. Observational data indicate that important components of the large-scale circulation have changed in recent decades, including the strength and the width of the Hadley cell, jets, storm tracks and planetary waves. Here, we use a new statistical-dynamical atmosphere model (SDAM) to test the individual sensitivities of the large-scale atmospheric circulation to changes in the zonal temperature gradient, meridional temperature gradient and global-mean temperature. We analyze the Northern Hemisphere Hadley circulation, jet streams, storm tracks and planetary waves by systematically altering the zonal temperature asymmetry, the meridional temperature gradient and the global-mean temperature. Our results show that the strength of the Hadley cell, storm tracks and jet streams depend, in terms of relative changes, almost linearly on both the global-mean temperature and the meridional temperature gradient, whereas the zonal temperature asymmetry has little or no influence. The magnitude of planetary waves is affected by all three temperature components, as expected from theoretical dynamical considerations. The width of the Hadley cell behaves nonlinearly with respect to all three temperature components in the SDAM. Moreover, some of these observed large-scale atmospheric changes are expected from dynamical equations and are therefore an important part of model validation.},
  language  = {en}
}
@article{GailletonMuddClubbetal.2019,
  author    = {Gailleton, Boris and Mudd, Simon M. and Clubb, Fiona J. and Peifer, Daniel and Hurst, Martin D.},
  title     = {A segmentation approach for the reproducible extraction and quantification of knickpoints from river long profiles},
  series = {Earth surface dynamics},
  volume    = {7},
  journal   = {Earth surface dynamics},
  number    = {1},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {2196-6311},
  doi       = {10.5194/esurf-7-211-2019},
  pages     = {211 -- 230},
  year      = {2019},
  abstract  = {Changes in the steepness of river profiles or abrupt vertical steps (i.e. waterfalls) are thought to be indicative of changes in erosion rates, lithology or other factors that affect landscape evolution. These changes are referred to as knickpoints or knickzones and are pervasive in bedrock river systems. Such features are thought to reveal information about landscape evolution and patterns of erosion, and therefore their locations are often reported in the geomorphic literature. It is imperative that studies reporting knickpoints and knickzones use a reproducible method of quantifying their locations, as their number and spatial distribution play an important role in interpreting tectonically active landscapes. In this contribution we introduce a reproducible knickpoint and knickzone extraction algorithm that uses river profiles transformed by integrating drainage area along channel length (the so-called integral or chi method). The profile is then statistically segmented and the differing slopes and step changes in the elevations of these segments are used to identify knickpoints, knickzones and their relative magnitudes. The output locations of identified knickpoints and knickzones compare favourably with human mapping: we test the method on Santa Cruz Island, CA, using previously reported knickzones and also test the method against a new dataset from the Quadrilatero Ferrifero in Brazil. The algorithm allows for the extraction of varying knickpoint morphologies, including stepped, positive slope-break (concave upward) and negative slope-break knickpoints. We identify parameters that most affect the resulting knickpoint and knickzone locations and provide guidance for both usage and outputs of the method to produce reproducible knickpoint datasets.},
  language  = {en}
}
@article{RodriguezZuluagaStolle2019,
  author    = {Rodriguez-Zuluaga, Juan and Stolle, Claudia},
  title     = {Interhemispheric field-aligned currents at the edges of equatorial plasma depletions},
  series = {Scientific reports},
  volume    = {9},
  journal   = {Scientific reports},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-018-37955-z},
  pages     = {8},
  year      = {2019},
  abstract  = {A comprehensive description of electromagnetic processes related to equatorial plasma depletions (EPDs) is essential for understanding their evolution and day-to-day variability. Recently, field-aligned currents (FACs) flowing at both western and eastern edges of EPDs were observed to be interhemispheric rather than anti-parallel about the dip equator, as suggested by previous theoretical studies. In this paper, we investigate the spatial and temporal variability of the FACs orientation using simultaneous measurements of electron density and magnetic field gathered by ESA's Swarm constellation mission. By using empirical models, we assess the role of the Pedersen conductance in the preference of the FACs to close either in the northern or southern magnetic hemisphere. Here we show that the closure of the FACs agrees with an electrostatic regime determined by a hemispherical asymmetry of the Pedersen conductance. That is, the EPD-related FACs close at lower altitudes in the hemisphere with the highest conductivity. The evidence of this conclusion stands on the general agreement between the longitudinal and seasonal variability of both the conductivity and the FACs orientation.},
  language  = {en}
}
@article{ReschkeRehfeldLaepple2019,
  author    = {Reschke, Maria and Rehfeld, Kira and Laepple, Thomas},
  title     = {Empirical estimate of the signal content of Holocene temperature proxy records},
  series = {Climate of the past : an interactive open access journal of the European Geosciences Union},
  volume    = {15},
  journal   = {Climate of the past : an interactive open access journal of the European Geosciences Union},
  number    = {2},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1814-9324},
  doi       = {10.5194/cp-15-521-2019},
  pages     = {521 -- 537},
  year      = {2019},
  abstract  = {Proxy records from climate archives provide evidence about past climate changes, but the recorded signal is affected by non-climate-related effects as well as time uncertainty. As proxy-based climate reconstructions are frequently used to test climate models and to quantitatively infer past climate, we need to improve our understanding of the proxy record signal content as well as the uncertainties involved. In this study, we empirically estimate signal-to-noise ratios (SNRs) of temperature proxy records used in global compilations of the middle to late Holocene (last 6000 years). This is achieved through a comparison of the correlation of proxy time series from nearby sites of three compilations and model time series extracted at the proxy sites from two transient climate model simulations: a Holocene simulation of the ECHAM5/MPI-OM model and the Holocene part of the TraCE-21ka simulation. In all comparisons, we found the mean correlations of the proxy time series on centennial to millennial timescales to be low (R < 0.2), even for nearby sites, which resulted in low SNR estimates. The estimated SNRs depend on the assumed time uncertainty of the proxy records, the timescale analysed, and the model simulation used. Using the spatial correlation structure of the ECHAM5/MPI-OM simulation, the estimated SNRs on centennial timescales ranged from 0.05 - assuming no time uncertainty - to 0.5 for a time uncertainty of 400 years. On millennial timescales, the estimated SNRs were generally higher. Use of the TraCE-21ka correlation structure generally resulted in lower SNR estimates than for ECHAM5/MPI-OM. As the number of available high-resolution proxy records continues to grow, a more detailed analysis of the signal content of specific proxy types should become feasible in the near future. The estimated low signal content of Holocene temperature compilations should caution against over-interpretation of these multi-proxy and multisite syntheses until further studies are able to facilitate a better characterisation of the signal content in paleoclimate records.},
  language  = {en}
}
@article{PetitgirardSahleWeisetal.2019,
  author    = {Petitgirard, Sylvian and Sahle, C. J. and Weis, C. and Gilmore, K. and Spiekermann, Georg and Tse, J. S. and Wilke, Max and Cavallari, C. and Cerantola, V and Sternemann, Christian},
  title     = {Magma properties at deep Earth's conditions from electronic structure of silica},
  series = {Geochemical perspectives letters},
  volume    = {9},
  journal   = {Geochemical perspectives letters},
  publisher = {Association of Geochemistry},
  address   = {Paris},
  issn      = {2410-339X},
  doi       = {10.7185/geochemlet.1902},
  pages     = {32 -- 37},
  year      = {2019},
  abstract  = {SiO(2 )is the main component of silicate melts and thus controls their network structure and physical properties. The compressibility and viscosities of melts at depth are governed by their short range atomic and electronic structure. We measured the O K-edge and the Si L-2,L-3-edge in silica up to 110 GPa using X-ray Raman scattering spectroscopy, and found a striking match to calculated spectra based on structures from molecular dynamic simulations. Between 20 and 27 GPa, Si-[4] species are converted into a mixture of Si-[5] and Si-[6] species and between 60 and 70 GPa, Si-[6] becomes dominant at the expense of Si-[5] with no further increase up to at least 110 GPa. Coordination higher than 6 is only reached beyond 140 GPa, corroborating results from Brillouin scattering. Network modifying elements in silicate melts may shift this change in coordination to lower pressures and thus magmas could be denser than residual solids at the depth of the core-mantle boundary.},
  language  = {en}
}
@article{ZornLeCorvecVarleyetal.2019,
  author    = {Zorn, Edgar Ulrich and Le Corvec, Nicolas and Varley, Nick R. and Salzer, Jacqueline T. and Walter, Thomas R. and Navarro-Ochoa, Carlos and Vargas-Bracamontes, Dulce M. and Thiele, Samuel T. and Ar{\´a}mbula Mendoza, Ra{\´u}l},
  title     = {Load stress controls on directional lava dome growth at Volcan de Colima, Mexico},
  series = {Frontiers in Earth Science},
  volume    = {7},
  journal   = {Frontiers in Earth Science},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {2296-6463},
  doi       = {10.3389/feart.2019.00084},
  pages     = {18},
  year      = {2019},
  abstract  = {During eruptive activity of andesitic stratovolcanoes, the extrusion of lava domes, their collapse and intermittent explosions are common volcanic hazards. Many lava domes grow in a preferred direction, in turn affecting the direction of lava flows and pyroclastic density currents. Access to active lava domes is difficult and hazardous, so detailed data characterizing lava dome growth are typically limited, keeping the processes controlling the directionality of extrusions unclear. Here we combine TerraSAR-X satellite radar observations with high-resolution airborne photogrammetry to assess morphological changes, and perform finite element modeling to investigate the impact of loading stress on shallow magma ascent directions associated with lava dome extrusion and crater formation at Volcan de Colima, Mexico. The TerraSAR-X data, acquired in similar to 1-m resolution spotlight mode, enable us to derive a chronology of the eruptive processes from intensity-based time-lapse observations of the general crater and dome evolution. The satellite images are complemented by close-range airborne photos, processed by the Structure-from-Motion workflow. This allows the derivation of high-resolution digital elevation models, providing insight into detailed loading and unloading features. During the observation period from Jan-2013 to Feb-2016, we identify a dominantly W-directed dome growth and lava flow production until Jan-2015. In Feb-2015, following the removal of the active summit dome, the surface crater widened and elongated along a NE-SW axis. Later in May-2015, a new dome grew toward the SW of the crater while a separate vent developed in the NE of the crater, reflecting a change in the direction of magma ascent and possible conduit bifurcation. Finite element models show a significant stress change in agreement with the observed magma ascent direction changes in response to the changing surface loads, both for loading (dome growth) and unloading (crater forming excavation) cases. These results allow insight into shallow dome growth dynamics and the migration of magma ascent in response to changing volcano summit morphology. They further highlight the importance of detailed volcano summit morphology surveillance, as changes in direction or location of dome extrusion may have major implications regarding the directions of potential volcanic hazards, such as pyroclastic density currents generated by dome collapse.},
  language  = {en}
}
@article{AsgarimehrWickertReich2019,
  author    = {Asgarimehr, Milad and Wickert, Jens and Reich, Sebastian},
  title     = {Evaluating impact of rain attenuation on space-borne GNSS reflectometry wind speeds},
  series = {Remote Sensing},
  volume    = {11},
  journal   = {Remote Sensing},
  number    = {9},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2072-4292},
  doi       = {10.3390/rs11091048},
  pages     = {18},
  year      = {2019},
  abstract  = {The novel space-borne Global Navigation Satellite System Reflectometry (GNSS-R) technique has recently shown promise in monitoring the ocean state and surface wind speed with high spatial coverage and unprecedented sampling rate. The L-band signals of GNSS are structurally able to provide a higher quality of observations from areas covered by dense clouds and under intense precipitation, compared to those signals at higher frequencies from conventional ocean scatterometers. As a result, studying the inner core of cyclones and improvement of severe weather forecasting and cyclone tracking have turned into the main objectives of GNSS-R satellite missions such as Cyclone Global Navigation Satellite System (CYGNSS). Nevertheless, the rain attenuation impact on GNSS-R wind speed products is not yet well documented. Evaluating the rain attenuation effects on this technique is significant since a small change in the GNSS-R can potentially cause a considerable bias in the resultant wind products at intense wind speeds. Based on both empirical evidence and theory, wind speed is inversely proportional to derived bistatic radar cross section with a natural logarithmic relation, which introduces high condition numbers (similar to ill-posed conditions) at the inversions to high wind speeds. This paper presents an evaluation of the rain signal attenuation impact on the bistatic radar cross section and the derived wind speed. This study is conducted simulating GNSS-R delay-Doppler maps at different rain rates and reflection geometries, considering that an empirical data analysis at extreme wind intensities and rain rates is impossible due to the insufficient number of observations from these severe conditions. Finally, the study demonstrates that at a wind speed of 30 m/s and incidence angle of 30 degrees, rain at rates of 10, 15, and 20 mm/h might cause overestimation as large as approximate to 0.65 m/s (2\%), 1.00 m/s (3\%), and 1.3 m/s (4\%), respectively, which are still smaller than the CYGNSS required uncertainty threshold. The simulations are conducted in a pessimistic condition (severe continuous rainfall below the freezing height and over the entire glistening zone) and the bias is expected to be smaller in size in real environments.},
  language  = {en}
}
@article{StichMartinMoralesetal.2020,
  author    = {Stich, Daniel and Martin, Rosa and Morales, Jose and Lopez-Comino, Jose Angel and Mancilla, Flor de Lis},
  title     = {Slip partitioning in the 2016 Alboran Sea earthquake sequence (western Mediterranean)},
  series = {Frontiers in Earth Science},
  volume    = {8},
  journal   = {Frontiers in Earth Science},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {2296-6463},
  doi       = {10.3389/feart.2020.587356},
  pages     = {19},
  year      = {2020},
  abstract  = {AM(W)= 5.1 earthquake on January 21st, 2016 marked the beginning of a significant seismic sequence in the southern Alboran Sea, culminating in aM(W)= 6.3 earthquake on January 25th, and continuing with further moderate magnitude earthquakes until March. We use data from 35 seismic broadband stations in Spain, Morocco and Portugal to relocate the seismicity, estimate seismic moment tensors, and isolate regional apparent source time functions for the main earthquake. Relocation and regional moment tensor inversion consistently yield very shallow depths for the majority of events. We obtain 50 moment tensors for the sequence, showing a mixture of strike-slip faulting for the foreshock and the main event and reverse faulting for the major aftershocks. The leading role of reverse focal mechanisms among the aftershocks may be explained by the geometry of the fault network. The mainshock nucleates at a bend along the left-lateral Al-Idrisi fault, introducing local transpression within the transtensional Alboran Basin. The shallow depths of the 2016 Alboran Sea earthquakes may favor slip-partitioning on the involved faults. Apparent source durations for the main event suggest a similar to 21 km long, asymmetric rupture that propagates primarily toward NE into the restraining fault segment, with fast rupture speed of similar to 3.0 km/s. Consistently, the inversion for laterally variable fault displacement situates the main slip in the restraining segment. The partitioning into strike-slip rupture and dip-slip aftershocks confirms a non-optimal orientation of this segment, and suggests that the 2016 event settled a slip deficit from previous ruptures that could not propagate into the stronger restraining segment.},
  language  = {en}
}
@article{CrisologoHeistermann2020,
  author    = {Crisologo, Irene and Heistermann, Maik},
  title     = {Using ground radar overlaps to verify the retrieval of calibration bias estimates from spaceborne platforms},
  series = {Atmospheric measurement techniques : an interactive open access journal of the European Geosciences Union},
  volume    = {13},
  journal   = {Atmospheric measurement techniques : an interactive open access journal of the European Geosciences Union},
  number    = {2},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1867-1381},
  doi       = {10.5194/amt-13-645-2020},
  pages     = {645 -- 659},
  year      = {2020},
  abstract  = {Many institutions struggle to tap into the potential of their large archives of radar reflectivity: these data are often affected by miscalibration, yet the bias is typically unknown and temporally volatile. Still, relative calibration techniques can be used to correct the measurements a posteriori. For that purpose, the usage of spaceborne reflectivity observations from the Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) platforms has become increasingly popular: the calibration bias of a ground radar (GR) is estimated from its average reflectivity difference to the spaceborne radar (SR). Recently, Crisologo et al. (2018) introduced a formal procedure to enhance the reliability of such estimates: each match between SR and GR observations is assigned a quality index, and the calibration bias is inferred as a quality-weighted average of the differences between SR and GR. The relevance of quality was exemplified for the Subic S-band radar in the Philippines, which is greatly affected by partial beam blockage. The present study extends the concept of quality-weighted averaging by accounting for path-integrated attenuation (PIA) in addition to beam blockage. This extension becomes vital for radars that operate at the C or X band. Correspondingly, the study setup includes a C-band radar that substantially overlaps with the S-band radar. Based on the extended quality-weighting approach, we retrieve, for each of the two ground radars, a time series of calibration bias estimates from suitable SR overpasses. As a result of applying these estimates to correct the ground radar observations, the consistency between the ground radars in the region of overlap increased substantially. Furthermore, we investigated if the bias estimates can be interpolated in time, so that ground radar observations can be corrected even in the absence of prompt SR overpasses. We found that a moving average approach was most suitable for that purpose, although limited by the absence of explicit records of radar maintenance operations.},
  language  = {en}
}
@article{WieczorekHerzschuh2020,
  author    = {Wieczorek, Mareike and Herzschuh, Ulrike},
  title     = {Compilation of relative pollen productivity (RPP) estimates and taxonomically harmonised RPP datasets for single continents and Northern Hemisphere extratropics},
  series = {Earth system science data : ESSD},
  volume    = {12},
  journal   = {Earth system science data : ESSD},
  number    = {4},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1866-3508},
  doi       = {10.5194/essd-12-3515-2020},
  pages     = {3515 -- 3528},
  year      = {2020},
  abstract  = {Relative pollen productivity (RPP) estimates are fractionate values, often in relation to Poaceae, that allow vegetation cover to be estimated from pollen counts with the help of models. RPP estimates are especially used in the scientific community in Europe and China, with a few studies in North America. Here we present a comprehensive compilation of available northern hemispheric RPP studies and their results arising from 51 publications with 60 sites and 131 taxa. This compilation allows scientists to identify data gaps in need of further RPP analyses but can also aid them in finding an RPP set for their study region. We also present a taxonomically harmonised, unified RPP dataset for the Northern Hemisphere and subsets for North America (including Greenland), Europe (including arctic Russia), and China, which we generated from the available studies. The unified dataset gives the mean RPP for 55 harmonised taxa as well as fall speeds, which are necessary to reconstruct vegetation cover from pollen counts and RPP values. Data are openly available at https://doi.org/10.1594/PANGAEA.922661 (Wieczorek and Herzschuh, 2020).},
  language  = {en}
}
@article{WetzelKempkaKuehn2020,
  author    = {Wetzel, Maria and Kempka, Thomas and K{\"u}hn, Michael},
  title     = {Hydraulic and mechanical impacts of pore space alterations within a sandstone quantified by a flow velocity-dependent precipitation approach},
  series = {Materials},
  volume    = {13},
  journal   = {Materials},
  number    = {14},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1996-1944},
  doi       = {10.3390/ma13143100},
  pages     = {20},
  year      = {2020},
  abstract  = {Geochemical processes change the microstructure of rocks and thereby affect their physical behaviour at the macro scale. A micro-computer tomography (micro-CT) scan of a typical reservoir sandstone is used to numerically examine the impact of three spatial alteration patterns on pore morphology, permeability and elastic moduli by correlating precipitation with the local flow velocity magnitude. The results demonstrate that the location of mineral growth strongly affects the permeability decrease with variations by up to four orders in magnitude. Precipitation in regions of high flow velocities is characterised by a predominant clogging of pore throats and a drastic permeability reduction, which can be roughly described by the power law relation with an exponent of 20. A continuous alteration of the pore structure by uniform mineral growth reduces the permeability comparable to the power law with an exponent of four or the Kozeny-Carman relation. Preferential precipitation in regions of low flow velocities predominantly affects smaller throats and pores with a minor impact on the flow regime, where the permeability decrease is considerably below that calculated by the power law with an exponent of two. Despite their complete distinctive impact on hydraulics, the spatial precipitation patterns only slightly affect the increase in elastic rock properties with differences by up to 6.3\% between the investigated scenarios. Hence, an adequate characterisation of the spatial precipitation pattern is crucial to quantify changes in hydraulic rock properties, whereas the present study shows that its impact on elastic rock parameters is limited. The calculated relations between porosity and permeability, as well as elastic moduli can be applied for upscaling micro-scale findings to reservoir-scale models to improve their predictive capabilities, what is of paramount importance for a sustainable utilisation of the geological subsurface.},
  language  = {en}
}
@article{WetzelKempkaKuehn2018,
  author    = {Wetzel, Maria and Kempka, Thomas and K{\"u}hn, Michael},
  title     = {Quantifying rock weakening due to decreasing calcite mineral content by numerical simulations},
  series = {Materials},
  volume    = {11},
  journal   = {Materials},
  number    = {4},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1996-1944},
  doi       = {10.3390/ma11040542},
  pages     = {19},
  year      = {2018},
  abstract  = {The quantification of changes in geomechanical properties due to chemical reactions is of paramount importance for geological subsurface utilisation, since mineral dissolution generally reduces rock stiffness. In the present study, the effective elastic moduli of two digital rock samples, the Fontainebleau and Bentheim sandstones, are numerically determined based on micro-CT images. Reduction in rock stiffness due to the dissolution of 10\% calcite cement by volume out of the pore network is quantified for three synthetic spatial calcite distributions (coating, partial filling and random) using representative sub-cubes derived from the digital rock samples. Due to the reduced calcite content, bulk and shear moduli decrease by 34\% and 38\% in maximum, respectively. Total porosity is clearly the dominant parameter, while spatial calcite distribution has a minor impact, except for a randomly chosen cement distribution within the pore network. Moreover, applying an initial stiffness reduced by 47\% for the calcite cement results only in a slightly weaker mechanical behaviour. Using the quantitative approach introduced here substantially improves the accuracy of predictions in elastic rock properties compared to general analytical methods, and further enables quantification of uncertainties related to spatial variations in porosity and mineral distribution.},
  language  = {en}
}
@article{NakatenKempka2019,
  author    = {Nakaten, Natalie Christine and Kempka, Thomas},
  title     = {Techno-Economic Comparison of Onshore and Offshore Underground Coal Gasification End-Product Competitiveness},
  series = {Energies},
  volume    = {12},
  journal   = {Energies},
  number    = {17},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1996-1073},
  doi       = {10.3390/en12173252},
  pages     = {28},
  year      = {2019},
  abstract  = {Underground coal gasification (UCG) enables utilization of coal reserves, currently not economically exploitable due to complex geological boundary conditions. Hereby, UCG produces a high-calorific synthesis gas that can be used for generation of electricity, fuels, and chemical feedstock. The present study aims to identify economically-competitive, site-specific end-use options for onshore- and offshore-produced UCG synthesis gas, taking into account the capture and storage (CCS) and/or utilization (CCU) of produced CO2. Modeling results show that boundary conditions favoring electricity, methanol, and ammonia production expose low costs for air separation, low compression power requirements, and appropriate shares of H-2/N-2. Hereby, a gasification agent ratio of more than 30\% oxygen by volume is not favorable from the economic and CO2 mitigation viewpoints. Compared to the costs of an offshore platform with its technical equipment, offshore drilling costs are marginal. Thus, uncertainties related to parameters influenced by drilling costs are negligible. In summary, techno-economic process modeling results reveal that air-blown gasification scenarios are the most cost-effective ones, while offshore UCG-CCS/CCU scenarios are up to 1.7 times more expensive than the related onshore processes. Hereby, all investigated onshore scenarios except from ammonia production under the assumed worst-case conditions are competitive on the European market.},
  language  = {en}
}
@article{ChengMilsch2020,
  author    = {Cheng, Chaojie and Milsch, Harald},
  title     = {Evolution of fracture aperture in quartz sandstone under hydrothermal conditions},
  series = {Minerals},
  volume    = {10},
  journal   = {Minerals},
  number    = {8},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2075-163X},
  doi       = {10.3390/min10080657},
  pages     = {18},
  year      = {2020},
  abstract  = {Fractures efficiently affect fluid flow in geological formations, and thereby determine mass and energy transport in reservoirs, which are not least exploited for economic resources. In this context, their response to mechanical and thermal changes, as well as fluid-rock interactions, is of paramount importance. In this study, a two-stage flow-through experiment was conducted on a pure quartz sandstone core of low matrix permeability, containing one single macroscopic tensile fracture. In the first short-term stage, the effects of mechanical and hydraulic aperture on pressure and temperature cycles were investigated. The purpose of the subsequent intermittent-flow long-term (140 days) stage was to constrain the evolution of the geometrical and hydraulic fracture properties resulting from pressure solution. Deionized water was used as the pore fluid, and permeability, as well as the effluent Si concentrations, were systematically measured. Overall, hydraulic aperture was shown to be significantly less affected by pressure, temperature and time, in comparison to mechanical aperture. During the long-term part of the experiment at 140 degrees C, the effluent Si concentrations likely reached a chemical equilibrium state within less than 8 days of stagnant flow, and exceeded the corresponding hydrostatic quartz solubility at this temperature. This implies that the pressure solution was active at the contacting fracture asperities, both at 140 degrees C and after cooling to 33 degrees C. The higher temperature yielded a higher dissolution rate and, consequently, a faster attainment of chemical equilibrium within the contact fluid. X-ray mu CT observations evidenced a noticeable increase in fracture contact area ratio, which, in combination with theoretical considerations, implies a significant decrease in mechanical aperture. In contrast, the sample permeability, and thus the hydraulic fracture aperture, virtually did not vary. In conclusion, pressure solution-induced fracture aperture changes are affected by the degree of time-dependent variations in pore fluid composition. In contrast to the present case of a quasi-closed system with mostly stagnant flow, in an open system with continuous once-through fluid flow, the activity of the pressure solution may be amplified due to the persistent fluid-chemical nonequilibrium state, thus possibly enhancing aperture and fracture permeability changes.},
  language  = {en}
}
@article{ScholzVoigt2022,
  author    = {Scholz, Carolin and Voigt, Christian C.},
  title     = {Diet analysis of bats killed at wind turbines suggests large-scale losses of trophic interactions},
  series = {Conservation science and practice},
  volume    = {4},
  journal   = {Conservation science and practice},
  number    = {7},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2578-4854},
  doi       = {10.1111/csp2.12744},
  pages     = {12},
  year      = {2022},
  abstract  = {Agricultural practice has led to landscape simplification and biodiversity decline, yet recently, energy-producing infrastructures, such as wind turbines, have been added to these simplified agroecosystems, turning them into multi-functional energy-agroecosystems. Here, we studied the trophic interactions of bats killed at wind turbines using a DNA metabarcoding approach to shed light on how turbine-related bat fatalities may possibly affect local habitats. Specifically, we identified insect DNA in the stomachs of common noctule bats (Nyctalus noctula) killed by wind turbines in Germany to infer in which habitats these bats hunted. Common noctule bats consumed a wide variety of insects from different habitats, ranging from aquatic to terrestrial ecosystems (e.g., wetlands, farmland, forests, and grasslands). Agricultural and silvicultural pest insects made up about 20\% of insect species consumed by the studied bats. Our study suggests that the potential damage of wind energy production goes beyond the loss of bats and the decline of bat populations. Bat fatalities at wind turbines may lead to the loss of trophic interactions and ecosystem services provided by bats, which may add to the functional simplification and impaired crop production, respectively, in multi-functional ecosystems.},
  language  = {en}
}
@article{BaesSobolevGeryaetal.2020,
  author    = {Baes, Marzieh and Sobolev, Stephan and Gerya, Taras V. and Brune, Sascha},
  title     = {Plume-induced subduction initiation},
  series = {Geochemistry, geophysics, geosystems},
  volume    = {21},
  journal   = {Geochemistry, geophysics, geosystems},
  number    = {2},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {1525-2027},
  doi       = {10.1029/2019GC008663},
  pages     = {19},
  year      = {2020},
  abstract  = {Initiation of subduction following the impingement of a hot buoyant mantle plume is one of the few scenarios that allow breaking the lithosphere and recycling a stagnant lid without requiring any preexisting weak zones. Here, we investigate factors controlling the number and shape of retreating subducting slabs formed by plume-lithosphere interaction. Using 3-D thermomechanical models we show that the deformation regime, which defines formation of single-slab or multi-slab subduction, depends on several parameters such as age of oceanic lithosphere, thickness of the crust and large-scale lithospheric extension rate. Our model results indicate that on present-day Earth multi-slab plume-induced subduction is initiated only if the oceanic lithosphere is relatively young (<30-40 Myr, but >10 Myr), and the crust has a typical thickness of 8 km. In turn, development of single-slab subduction is facilitated by older lithosphere and pre-imposed extensional stresses. In early Earth, plume-lithosphere interaction could have led to formation of either episodic short-lived circular subduction when the oceanic lithosphere was young or to multi-slab subduction when the lithosphere was old.},
  language  = {en}
}
@article{BaesSobolevGeryaetal.2020,
  author    = {Baes, Marzieh and Sobolev, Stephan V. and Gerya, Taras V. and Brune, Sascha},
  title     = {Subduction initiation by Plume-Plateau interaction},
  series = {Geochemistry, geophysics, geosystems},
  volume    = {21},
  journal   = {Geochemistry, geophysics, geosystems},
  number    = {8},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {1525-2027},
  doi       = {10.1029/2020GC009119},
  pages     = {17},
  year      = {2020},
  abstract  = {It has recently been demonstrated that the interaction of a mantle plume with sufficiently old oceanic lithosphere can initiate subduction. However, the existence of large lithospheric heterogeneities, such as a buoyant plateau, in proximity to a rising plume head may potentially hinder the formation of a new subduction zone. Here, we investigate this scenario by means of 3-D numerical thermomechanical modeling. We explore how plume-lithosphere interaction is affected by lithospheric age, relative location of plume head and plateau border, and the strength of the oceanic crust. Our numerical experiments suggest four different geodynamic regimes: (a) oceanic trench formation, (b) circular oceanic-plateau trench formation, (c) plateau trench formation, and (d) no trench formation. We show that regardless of the age and crustal strength of the oceanic lithosphere, subduction can initiate when the plume head is either below the plateau border or at a distance less than the plume radius from the plateau edge. Crustal heterogeneity facilitates subduction initiation of old oceanic lithosphere. High crustal strength hampers the formation of a new subduction zone when the plume head is located below a young lithosphere containing a thick and strong plateau. We suggest that plume-plateau interaction in the western margin of the Caribbean could have resulted in subduction initiation when the plume head impinged onto the oceanic lithosphere close to the border between plateau and oceanic crust.},
  language  = {en}
}
@article{ScherlerSchwanghart2020,
  author    = {Scherler, Dirk and Schwanghart, Wolfgang},
  title     = {Drainage divide networks},
  series = {Earth surface dynamics},
  volume    = {8},
  journal   = {Earth surface dynamics},
  number    = {2},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {2196-6311},
  doi       = {10.5194/esurf-8-261-2020},
  pages     = {261 -- 274},
  year      = {2020},
  abstract  = {Drainage divides are organized into tree-like networks that may record information about drainage divide mobility. However, views diverge about how to best assess divide mobility. Here, we apply a new approach of automatically extracting and ordering drainage divide networks from digital elevation models to results from landscape evolution model experiments. We compared landscapes perturbed by strike-slip faulting and spatiotemporal variations in erodibility to a reference model to assess which topographic metrics (hillslope relief, flow distance, and chi) are diagnostic of divide mobility. Results show that divide segments that are a minimum distance of similar to 5 km from river confluences strive to attain constant values of hillslope relief and flow distance to the nearest stream. Disruptions of such patterns can be related to mobile divides that are lower than stable divides, closer to streams, and often asymmetric in shape. In general, we observe that drainage divides high up in the network, i.e., at great distances from river confluences, are more susceptible to disruptions than divides closer to these confluences and are thus more likely to record disturbance for a longer time period. We found that across-divide differences in hillslope relief proved more useful for assessing divide migration than other tested metrics. However, even stable drainage divide networks exhibit across-divide differences in any of the studied topographic metrics. Finally, we propose a new metric to quantify the connectivity of divide junctions.},
  language  = {en}
}
@article{RolphOverduinRavensetal.2022,
  author    = {Rolph, Rebecca and Overduin, Pier Paul and Ravens, Thomas and Lantuit, Hugues and Langer, Moritz},
  title     = {ArcticBeach v1.0},
  series = {Frontiers in Earth Science},
  volume    = {10},
  journal   = {Frontiers in Earth Science},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {2296-6463},
  doi       = {10.3389/feart.2022.962208},
  pages     = {19},
  year      = {2022},
  abstract  = {In the Arctic, air temperatures are increasing and sea ice is declining, resulting in larger waves and a longer open water season, all of which intensify the thaw and erosion of ice-rich coasts. Climate change has been shown to increase the rate of Arctic coastal erosion, causing problems for Arctic cultural heritage, existing industrial, military, and civil infrastructure, as well as changes in nearshore biogeochemistry. Numerical models that reproduce historical and project future Arctic erosion rates are necessary to understand how further climate change will affect these problems, and no such model yet exists to simulate the physics of erosion on a pan-Arctic scale. We have coupled a bathystrophic storm surge model to a simplified physical erosion model of a permafrost coastline. This Arctic erosion model, called ArcticBeach v1.0, is a first step toward a physical parameterization of Arctic shoreline erosion for larger-scale models. It is forced by wind speed and direction, wave period and height, sea surface temperature, all of which are masked during times of sea ice cover near the coastline. Model tuning requires observed historical retreat rates (at least one value), as well as rough nearshore bathymetry. These parameters are already available on a pan-Arctic scale. The model is validated at three study sites at 1) Drew Point (DP), Alaska, 2) Mamontovy Khayata (MK), Siberia, and 3) Veslebogen Cliffs, Svalbard. Simulated cumulative retreat rates for DP and MK respectively (169 and 170 m) over the time periods studied at each site (2007-2016, and 1995-2018) are found to the same order of magnitude as observed cumulative retreat (172 and 120 m). The rocky Veslebogen cliffs have small observed cumulative retreat rates (0.05 m over 2014-2016), and our model was also able to reproduce this same order of magnitude of retreat (0.08 m). Given the large differences in geomorphology between the study sites, this study provides a proof-of-concept that ArcticBeach v1.0 can be applied on very different permafrost coastlines. ArcticBeach v1.0 provides a promising starting point to project retreat of Arctic shorelines, or to evaluate historical retreat in places that have had few observations.},
  language  = {en}
}
@article{HeckenbachBruneGlerumetal.2021,
  author    = {Heckenbach, Esther Lina and Brune, Sascha and Glerum, Anne C. and Bott, Judith},
  title     = {Is there a speed limit for the thermal steady-state assumption in continental rifts?},
  series = {Geochemistry, geophysics, geosystems : G 3 ; an electronic journal of the earth sciences},
  volume    = {22},
  journal   = {Geochemistry, geophysics, geosystems : G 3 ; an electronic journal of the earth sciences},
  number    = {3},
  publisher = {Wiley},
  address   = {Hoboken, NJ},
  issn      = {1525-2027},
  doi       = {10.1029/2020GC009577},
  pages     = {18},
  year      = {2021},
  abstract  = {The lithosphere is often assumed to reside in a thermal steady-state when quantitatively describing the temperature distribution in continental interiors and sedimentary basins, but also at active plate boundaries. Here, we investigate the applicability limit of this assumption at slowly deforming continental rifts. To this aim, we assess the tectonic thermal imprint in numerical experiments that cover a range of realistic rift configurations. For each model scenario, the deviation from thermal equilibrium is evaluated. This is done by comparing the transient temperature field of every model to a corresponding steady-state model with an identical structural configuration. We find that the validity of the thermal steady-state assumption strongly depends on rift type, divergence velocity, sampling location, and depth within the rift. Maximum differences between transient and steady-state models occur in narrow rifts, at the rift sides, and if the extension rate exceeds 0.5-2 mm/a. Wide rifts, however, reside close to thermal steady-state even for high extension velocities. The transient imprint of rifting appears to be overall negligible for shallow isotherms with a temperature less than 100 degrees C. Contrarily, a steady-state treatment of deep crustal isotherms leads to an underestimation of crustal temperatures, especially for narrow rift settings. Thus, not only relatively fast rifts like the Gulf of Corinth, Red Sea, and Main Ethiopian Rift, but even slow rifts like the Kenya Rift, Rhine Graben, and Rio Grande Rift must be expected to feature a pronounced transient component in the temperature field and to therefore violate the thermal steady-state assumption for deeper crustal isotherms.},
  language  = {en}
}
@article{DeLuciaKuehn2021,
  author    = {De Lucia, Marco and K{\"u}hn, Michael},
  title     = {DecTree v1.0-chemistry speedup in reactive transport simulations},
  series = {Geoscientific model development : an interactive open access journal of the European Geosciences Union},
  volume    = {14},
  journal   = {Geoscientific model development : an interactive open access journal of the European Geosciences Union},
  number    = {7},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1991-959X},
  doi       = {10.5194/gmd-14-4713-2021},
  pages     = {4713 -- 4730},
  year      = {2021},
  abstract  = {The computational costs associated with coupled reactive transport simulations are mostly due to the chemical subsystem: replacing it with a pre-trained statistical surrogate is a promising strategy to achieve decisive speedups at the price of small accuracy losses and thus to extend the scale of problems which can be handled. We introduce a hierarchical coupling scheme in which "full-physics" equation-based geochemical simulations are partially replaced by surrogates. Errors in mass balance resulting from multivariate surrogate predictions effectively assess the accuracy of multivariate regressions at runtime: inaccurate surrogate predictions are rejected and the more expensive equation-based simulations are run instead. Gradient boosting regressors such as XGBoost, not requiring data standardization and being able to handle Tweedie distributions, proved to be a suitable emulator. Finally, we devise a surrogate approach based on geochemical knowledge, which overcomes the issue of robustness when encountering previously unseen data and which can serve as a basis for further development of hybrid physics-AI modelling.},
  language  = {en}
}
@article{RamageIrrgangMorgensternetal.2018,
  author    = {Ramage, Justine Lucille and Irrgang, Anna Maria and Morgenstern, Anne and Lantuit, Hugues},
  title     = {Increasing coastal slump activity impacts the release of sediment and organic carbon into the Arctic Ocean},
  series = {Biogeosciences},
  volume    = {15},
  journal   = {Biogeosciences},
  number    = {5},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1726-4170},
  doi       = {10.5194/bg-15-1483-2018},
  pages     = {1483 -- 1495},
  year      = {2018},
  abstract  = {Retrogressive thaw slumps (RTSs) are among the most active thermokarst landforms in the Arctic and deliver a large amount of material to the Arctic Ocean. However, their contribution to the organic carbon (OC) budget is unknown. We provide the first estimate of the contribution of RTSs to the nearshore OC budget of the Yukon Coast, Canada, and describe the evolution of coastal RTSs between 1952 and 2011 in this area. We (1) describe the evolution of RTSs between 1952 and 2011; (2) calculate the volume of eroded material and stocks of OC mobilized through slumping, including soil organic carbon (SOC) and dissolved organic carbon (DOC); and (3) estimate the OC fluxes mobilized through slumping between 1972 and 2011. We identified RTSs using high- resolution satellite imagery from 2011 and geocoded aerial photographs from 1952 and 1972. To estimate the volume of eroded material, we applied spline interpolation on an airborne lidar dataset acquired in July 2013. We inferred the stocks of mobilized SOC and DOC from existing related literature. Our results show a 73\% increase in the number of RTSs and 14\% areal expansion between 1952 and 2011. In the study area, RTSs displaced at least 16.6 x 10(6) m(3) of material, 53\% of which was ice, and mobilized 145.9 x 10(6) kg of OC. Between 1972 and 2011, 49 RTSs displaced 8.6 x 10(3) m(3) yr(-1) of material, adding 0.6\% to the OC flux released by coastal retreat along the Yukon Coast. Our results show that the contribution of RTSs to the nearshore OC budget is non-negligible and should be included when estimating the quantity of OC released from the Arctic coast to the ocean.},
  language  = {en}
}
@article{NicoliFerrero2021,
  author    = {Nicoli, Gautier and Ferrero, Silvio},
  title     = {Nanorocks, volatiles and plate tectonics},
  series = {Geoscience frontiers},
  volume    = {12},
  journal   = {Geoscience frontiers},
  number    = {5},
  publisher = {Amsterdam [u.a.]},
  address   = {Elsevier},
  issn      = {1674-9871},
  doi       = {10.1016/j.gsf.2021.101188},
  pages     = {13},
  year      = {2021},
  abstract  = {The global geological volatile cycle (H, C, N) plays an important role in the long term self-regulation of the Earth system. However, the complex interaction between its deep, solid Earth components (i.e. crust and mantle), Earth's fluid envelopes (i.e. atmosphere and hydrosphere) and plate tectonic processes is a subject of ongoing debate. In this study we want to draw attention to how the presence of primary melt (MI) and fluid (FI) inclusions in high-grade metamorphic minerals could help constrain the crustal component of the volatile cycle. To that end, we review the distribution of MI and FI throughout Earth's history, from ca. 3.0 Ga ago up to the present day. We argue that the lower crust might constitute an important, long-term, volatile storage unit, capable to influence the composition of the surface envelopes through the mean of weathering, crustal thickening, partial melting and crustal assimilation during volcanic activity. Combined with thermodynamic modelling, our compilation indicates that periods of well-established plate tectonic regimes at <0.85 Ga and 1.7-2.1 Ga, might be more prone to the reworking of supracrustal lithologies and the storage of volatiles in the lower crust. Such hypothesis has implication beyond the scope of metamorphic petrology as it potentially links geodynamic mechanisms to habitable surface conditions. MI and FI in metamorphic crustal rocks then represent an invaluable archive to assess and quantify the co-joint evolution of plate tectonics and Earth's external processes. (C) 2021 China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).},
  language  = {en}
}
@article{KwiatekSaarnoAderetal.2019,
  author    = {Kwiatek, Grzegorz and Saarno, Tero and Ader, Thomas and Bl{\"u}mle, Felix and Bohnhoff, Marco and Chendorain, Michael and Dresen, Georg and Heikkinen, Pekka and Kukkonen, Ilmo and Leary, Peter and Leonhardt, Maria and Malin, Peter and Martinez-Garzon, Patricia and Passmore, Kevin and Passmore, Paul and Valenzuela, Sergio and Wollin, Christopher},
  title     = {Controlling fluid-induced seismicity during a 6.1-km-deep geothermal stimulation in Finland},
  series = {Science Advances},
  volume    = {5},
  journal   = {Science Advances},
  number    = {5},
  publisher = {American Association for the Advancement of Science},
  address   = {Washington},
  issn      = {2375-2548},
  doi       = {10.1126/sciadv.aav7224},
  pages     = {11},
  year      = {2019},
  abstract  = {We show that near-real-time seismic monitoring of fluid injection allowed control of induced earthquakes during the stimulation of a 6.1-km-deep geothermal well near Helsinki, Finland. A total of 18,160 m(3) of fresh water was pumped into crystalline rocks over 49 days in June to July 2018. Seismic monitoring was performed with a 24-station borehole seismometer network. Using near-real-time information on induced-earthquake rates, locations, magnitudes, and evolution of seismic and hydraulic energy, pumping was either stopped or varied-in the latter case, between well-head pressures of 60 and 90 MPa and flow rates of 400 and 800 liters/min. This procedure avoided the nucleation of a project-stopping magnitude M-W 2.0 induced earthquake, a limit set by local authorities. Our results suggest a possible physics-based approach to controlling stimulation-induced seismicity in geothermal projects.},
  language  = {en}
}
@article{RoudWackGilderetal.2021,
  author    = {Roud, Sophie and Wack, Michael Richard and Gilder, Stuart A. and Kudriavtseva, Anna and Sobel, Edward},
  title     = {Miocene to early pleistocene depositional history and tectonic evolution of the Issyk-Kul Basin, Central Tian Shan},
  series = {Geochemistry, geophysics, geosystems : G 3 ; an electronic journal of the earth sciences},
  volume    = {22},
  journal   = {Geochemistry, geophysics, geosystems : G 3 ; an electronic journal of the earth sciences},
  number    = {4},
  publisher = {Wiley},
  address   = {Hoboken, NJ},
  issn      = {1525-2027},
  doi       = {10.1029/2020GC009556},
  pages     = {16},
  year      = {2021},
  abstract  = {The Issyk-Kul Basin (Kyrgyzstan), situated in the central Tian Shan Mountains, hosts the largest and deepest mountain lake in Central Asia. Erosion of the surrounding Terskey and Kungey ranges led to the accumulation of up to 4 km of sediment in the adjacent depression. Creation of the basin from regional shortening and uplift likely initiated around the Oligocene-Miocene, yet precise age control is sparse. To better understand the timing of these processes, we obtained magnetostratigraphic age constraints on fossil-poor, fluvio-lacustrine sediments exposed south of Lake Issyk-Kul, that agree well with previous age constraints of the equivalent strata outside the Issyk-Kul Basin. Two 500-650 m thick sections comprised mainly of Chu Group sediments were dated at 6.3-2.8 Ma and 7.0-2.4 Ma (late Miocene to early Pleistocene). Together with reinterpreted magnetostratigraphic constraints from underlying strata, we find that syn-tectonic deposition commenced at similar to 22 Ma with average sedimentation rates <10 cm/ka. Sedimentation rates increased to 10-30 cm/ka at 7 Ma, concurrent with accelerated uplift in the Terskey Range to the south. A deformation event in one section (Kaji-Say) between 5 and 3 Ma together with concurrent shifts of depositional centers throughout the basin signal the onset of substantial uplift of the Kungey Range to the north at similar to 5 Ma. This uplift and deformation transformed the Issyk-Kul area into a closed basin that facilitated the formation of a deep lake. Lacustrine facies deposited around 3 Ma mark the existence of Lake Issyk-Kul by that time.},
  language  = {en}
}
@article{HennigKuehn2021,
  author    = {Hennig, Theresa and K{\"u}hn, Michael},
  title     = {Surrogate model for multi-component diffusion of Uranium through Opalinus Clay on the host rock scale},
  series = {Applied Sciences : open access journal},
  volume    = {11},
  journal   = {Applied Sciences : open access journal},
  number    = {2},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2076-3417},
  doi       = {10.3390/app11020786},
  pages     = {21},
  year      = {2021},
  abstract  = {Multi-component (MC) diffusion simulations enable a process based and more precise approach to calculate transport and sorption compared to the commonly used single-component (SC) models following Fick's law. The MC approach takes into account the interaction of chemical species in the porewater with the diffuse double layer (DDL) adhering clay mineral surfaces. We studied the shaly, sandy and carbonate-rich facies of the Opalinus Clay. High clay contents dominate diffusion and sorption of uranium. The MC simulations show shorter diffusion lengths than the SC models due to anion exclusion from the DDL. This hampers diffusion of the predominant species CaUO2(CO3)32-. On the one side, species concentrations and ionic strengths of the porewater and on the other side surface charge of the clay minerals control the composition and behaviour of the DDL. For some instances, it amplifies the diffusion of uranium. We developed a workflow to transfer computationally intensive MC simulations to SC models via calibrated effective diffusion and distribution coefficients. Simulations for one million years depict maximum uranium diffusion lengths between 10 m and 35 m. With respect to the minimum requirement of a thickness of 100 m, the Opalinus Clay seems to be a suitable host rock for nuclear waste repositories.},
  language  = {en}
}
@article{DiBaldassarreKreibichVorogushynetal.2018,
  author    = {Di Baldassarre, Giuliano and Kreibich, Heidi and Vorogushyn, Sergiy and Aerts, Jeroen and Arnbjerg-Nielsen, Karsten and Barendrecht, Marlies and Bates, Paul and Borga, Marco and Botzen, Wouter and Bubeck, Philip and De Marchi, Bruna and Llasat, Carmen Maria and Mazzoleni, Maurizio and Molinari, Daniela and Mondino, Elena and Mard, Johanna and Petrucci, Olga and Scolobig, Anna and Viglione, Alberto and Ward, Philip J.},
  title     = {Hess Opinions: An interdisciplinary research agenda to explore the unintended consequences of structural flood protection},
  series = {Hydrology and earth system sciences : HESS},
  volume    = {22},
  journal   = {Hydrology and earth system sciences : HESS},
  number    = {11},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1027-5606},
  doi       = {10.5194/hess-22-5629-2018},
  pages     = {5629 -- 5637},
  year      = {2018},
  abstract  = {One common approach to cope with floods is the implementation of structural flood protection measures, such as levees or flood-control reservoirs, which substantially reduce the probability of flooding at the time of implementation. Numerous scholars have problematized this approach. They have shown that increasing the levels of flood protection can attract more settlements and high-value assets in the areas protected by the new measures. Other studies have explored how structural measures can generate a sense of complacency, which can act to reduce preparedness. These paradoxical risk changes have been described as "levee effect", "safe development paradox" or "safety dilemma". In this commentary, we briefly review this phenomenon by critically analysing the intended benefits and unintended effects of structural flood protection, and then we propose an interdisciplinary research agenda to uncover these paradoxical dynamics of risk.},
  language  = {en}
}
@article{PanSchicks2021,
  author    = {Pan, Mengdi and Schicks, Judith M.},
  title     = {Influence of gas supply changes on the formation process of complex mixed gas hydrates},
  series = {Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International},
  volume    = {26},
  journal   = {Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International},
  number    = {10},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1420-3049},
  doi       = {10.3390/molecules26103039},
  pages     = {18},
  year      = {2021},
  abstract  = {Natural gas hydrate occurrences contain predominantly methane; however, there are increasing reports of complex mixed gas hydrates and coexisting hydrate phases. Changes in the feed gas composition due to the preferred incorporation of certain components into the hydrate phase and an inadequate gas supply is often assumed to be the cause of coexisting hydrate phases. This could also be the case for the gas hydrate system in Qilian Mountain permafrost (QMP), which is mainly controlled by pores and fractures with complex gas compositions. This study is dedicated to the experimental investigations on the formation process of mixed gas hydrates based on the reservoir conditions in QMP. Hydrates were synthesized from water and a gas mixture under different gas supply conditions to study the effects on the hydrate formation process. In situ Raman spectroscopic measurements and microscopic observations were applied to record changes in both gas and hydrate phase over the whole formation process. The results demonstrated the effects of gas flow on the composition of the resulting hydrate phase, indicating a competitive enclathration of guest molecules into the hydrate lattice depending on their properties. Another observation was that despite significant changes in the gas composition, no coexisting hydrate phases were formed.},
  language  = {en}
}
@article{CochJuhlsLamoureuxetal.2019,
  author    = {Coch, Caroline and Juhls, Bennet and Lamoureux, Scott F. and Lafreniere, Melissa J. and Fritz, Michael and Heim, Birgit and Lantuit, Hugues},
  title     = {Comparisons of dissolved organic matter and its optical characteristics in small low and high Arctic catchments},
  series = {Biogeosciences},
  volume    = {16},
  journal   = {Biogeosciences},
  number    = {23},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1726-4170},
  doi       = {10.5194/bg-16-4535-2019},
  pages     = {4535 -- 4553},
  year      = {2019},
  abstract  = {Climate change is affecting the rate of carbon cycling, particularly in the Arctic. Permafrost degradation through deeper thaw and physical disturbances results in the release of carbon dioxide and methane to the atmosphere and to an increase in lateral dissolved organic matter (DOM) fluxes. Whereas riverine DOM fluxes of the large Arctic rivers are well assessed, knowledge is limited with regard to small catchments that cover more than 40\% of the Arctic drainage basin. Here, we use absorption measurements to characterize changes in DOM quantity and quality in a low Arctic (Herschel Island, Yukon, Canada) and a high Arctic (Cape Bounty, Melville Island, Nunavut, Canada) setting with regard to geographical differences, impacts of permafrost degradation, and rainfall events. We find that DOM quantity and quality is controlled by differences in vegetation cover and soil organic carbon content (SOCC). The low Arctic site has higher SOCC and greater abundance of plant material resulting in higher chromophoric dissolved organic matter (cDOM) and dissolved organic carbon (DOC) than in the high Arctic. DOC concentration and cDOM in surface waters at both sites show strong linear relationships similar to the one for the great Arctic rivers. We used the optical characteristics of DOM such as cDOM absorption, specific ultraviolet absorbance (SUVA), ultraviolet (UV) spectral slopes (S275-295), and slope ratio (SR) for assessing quality changes downstream, at base flow and storm flow conditions, and in relation to permafrost disturbance. DOM in streams at both sites demonstrated optical signatures indicative of photodegradation downstream processes, even over short distances of 2000 m. Flow pathways and the connected hydrological residence time control DOM quality. Deeper flow pathways allow the export of permafrost-derived DOM (i.e. from deeper in the active layer), whereas shallow pathways with shorter residence times lead to the export of fresh surface- and near-surface-derived DOM. Compared to the large Arctic rivers, DOM quality exported from the small catchments studied here is much fresher and therefore prone to degradation. Assessing optical properties of DOM and linking them to catchment properties will be a useful tool for understanding changing DOM fluxes and quality at a pan-Arctic scale.},
  language  = {en}
}
@article{WetzelKempkaKuehn2021,
  author    = {Wetzel, Maria and Kempka, Thomas and K{\"u}hn, Michael},
  title     = {Diagenetic trends of synthetic reservoir sandstone properties assessed by digital rock physics},
  series = {Minerals},
  volume    = {11},
  journal   = {Minerals},
  number    = {2},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2075-163X},
  doi       = {10.3390/min11020151},
  pages     = {21},
  year      = {2021},
  abstract  = {Quantifying interactions and dependencies among geometric, hydraulic and mechanical properties of reservoir sandstones is of particular importance for the exploration and utilisation of the geological subsurface and can be assessed by synthetic sandstones comprising the microstructural complexity of natural rocks. In the present study, three highly resolved samples of the Fontainebleau, Berea and Bentheim sandstones are generated by means of a process-based approach, which combines the gravity-driven deposition of irregularly shaped grains and their diagenetic cementation by three different schemes. The resulting evolution in porosity, permeability and rock stiffness is examined and compared to the respective micro-computer tomographic (micro-CT) scans. The grain contact-preferential scheme implies a progressive clogging of small throats and consequently produces considerably less connected and stiffer samples than the two other schemes. By contrast, uniform quartz overgrowth continuously alters the pore space and leads to the lowest elastic properties. The proposed stress-dependent cementation scheme combines both approaches of contact-cement and quartz overgrowth, resulting in granulometric, hydraulic and elastic properties equivalent to those of the respective micro-CT scans, where bulk moduli slightly deviate by 0.8\%, 4.9\% and 2.5\% for the Fontainebleau, Berea and Bentheim sandstone, respectively. The synthetic samples can be further altered to examine the impact of mineral dissolution or precipitation as well as fracturing on various petrophysical correlations, which is of particular relevance for numerous aspects of a sustainable subsurface utilisation.},
  language  = {en}
}
@article{StedingKempkaKuehn2021,
  author    = {Steding, Svenja and Kempka, Thomas and K{\"u}hn, Michael},
  title     = {How insoluble inclusions and intersecting layers affect the leaching process within potash seams},
  series = {Applied Sciences : open access journal},
  volume    = {11},
  journal   = {Applied Sciences : open access journal},
  number    = {19},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2076-3417},
  doi       = {10.3390/app11199314},
  pages     = {21},
  year      = {2021},
  abstract  = {Potash seams are a valuable resource containing several economically interesting, but also highly soluble minerals. In the presence of water, uncontrolled leaching can occur, endangering subsurface mining operations. In the present study, the influence of insoluble inclusions and intersecting layers on leaching zone evolution was examined by means of a reactive transport model. For that purpose, a scenario analysis was carried out, considering different rock distributions within a carnallite-bearing potash seam. The results show that reaction-dominated systems are not affected by heterogeneities at all, whereas transport-dominated systems exhibit a faster advance in homogeneous rock compositions. In return, the ratio of permeated rock in vertical direction is higher in heterogeneous systems. Literature data indicate that most natural potash systems are transport-dominated. Accordingly, insoluble inclusions and intersecting layers can usually be seen as beneficial with regard to reducing hazard potential as long as the mechanical stability of leaching zones is maintained. Thereby, the distribution of insoluble areas is of minor impact unless an inclined, intersecting layer occurs that accelerates leaching zone growth in one direction. Moreover, it is found that the saturation dependency of dissolution rates increases the growth rate in the long term, and therefore must be considered in risk assessments.},
  language  = {en}
}
@article{ZimmermannStoofLeichsenringKruseetal.2020,
  author    = {Zimmermann, Heike Hildegard and Stoof-Leichsenring, Kathleen Rosemarie and Kruse, Stefan and M{\"u}ller, Juliane and Stein, Ruediger and Tiedemann, Ralf and Herzschuh, Ulrike},
  title     = {Changes in the composition of marine and sea-ice diatoms derived from sedimentary ancient DNA of the eastern Fram Strait over the past 30 000 years},
  series = {Ocean science},
  volume    = {16},
  journal   = {Ocean science},
  number    = {5},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1812-0784},
  doi       = {10.5194/os-16-1017-2020},
  pages     = {1017 -- 1032},
  year      = {2020},
  abstract  = {The Fram Strait is an area with a relatively low and irregular distribution of diatom microfossils in surface sediments, and thus microfossil records are scarce, rarely exceed the Holocene, and contain sparse information about past richness and taxonomic composition. These attributes make the Fram Strait an ideal study site to test the utility of sedimentary ancient DNA (sedaDNA) metabarcoding. Amplifying a short, partial rbcL marker from samples of sediment core MSM05/5-712-2 resulted in 95.7\% of our sequences being assigned to diatoms across 18 different families, with 38.6\% of them being resolved to species and 25.8\% to genus level. Independent replicates show a high similarity of PCR products, especially in the oldest samples. Diatom sedaDNA richness is highest in the Late Weichselian and lowest in Mid- and Late Holocene samples. Taxonomic composition is dominated by cold-water and sea-ice-associated diatoms and suggests several reorganisations - after the Last Glacial Maximum, after the Younger Dryas, and after the Early and after the Mid-Holocene. Different sequences assigned to, amongst others, Chaetoceros socialis indicate the detectability of intra-specific diversity using sedaDNA. We detect no clear pattern between our diatom sedaDNA record and the previously published IP25 record of this core, although proportions of pennate diatoms increase with higher IP25 concentrations and proportions of Nitzschia cf. frigida exceeding 2\% of the assemblage point towards past sea-ice presence.},
  language  = {en}
}
@article{GuzmanSamprognaMohorMendiondo2020,
  author    = {Guzman, Diego A. and Samprogna Mohor, Guilherme and Mendiondo, Eduardo Mario},
  title     = {Multi-year index-based insurance for adapting Water Utility Companies to hydrological drought},
  series = {Water},
  volume    = {12},
  journal   = {Water},
  number    = {11},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2073-4441},
  doi       = {10.3390/w12112954},
  pages     = {22},
  year      = {2020},
  abstract  = {The sustainability of water utility companies is threatened by non-stationary drivers, such as climate and anthropogenic changes. To cope with potential economic losses, instruments such as insurance are useful for planning scenarios and mitigating impacts, but data limitations and risk uncertainties affect premium estimation and, consequently, business sustainability. This research estimated the possible economic impacts of business interruption to the Sao Paulo Water Utility Company derived from hydrological drought and how this could be mitigated with an insurance scheme. Multi-year insurance (MYI) was proposed through a set of "change" drivers: the climate driver, through forcing the water evaluation and planning system (WEAP) hydrological tool; the anthropogenic driver, through water demand projections; and the economic driver, associated with recent water price policies adopted by the utility company during water scarcity periods. In our study case, the evaluated indices showed that MYI contracts that cover only longer droughts, regardless of the magnitude, offer better financial performance than contracts that cover all events (in terms of drought duration). Moreover, through MYI contracts, we demonstrate solvency for the insurance fund in the long term and an annual average actuarially fair premium close to the total expected revenue reduction.},
  language  = {en}
}
@article{Braun2022,
  author    = {Braun, Jean},
  title     = {Comparing the transport-limited and ξ-q models for sediment transport},
  series = {Earth surface dynamics},
  volume    = {10},
  journal   = {Earth surface dynamics},
  number    = {2},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {2196-6311},
  doi       = {10.5194/esurf-10-301-2022},
  pages     = {301 -- 327},
  year      = {2022},
  abstract  = {Here I present a comparison between two of the most widely used reduced-complexity models for the representation of sediment transport and deposition processes, namely the transport-limited (or TL) model and the under-capacity (or xi-q) model more recently developed by Davy and Lague (2009). Using both models, I investigate the behavior of a sedimentary continental system of length L fed by a fixed sedimentary flux from a catchment of size A(0) in a nearby active orogen through which sediments transit to a fixed base level representing a large river, a lake or an ocean. This comparison shows that the two models share the same steady-state solution, for which I derive a simple 1D analytical expression that reproduces the major features of such sedimentary systems: a steep fan that connects to a shallower alluvial plain. The resulting fan geometry obeys basic observational constraints on fan size and slope with respect to the upstream drainage area, A(0). The solution is strongly dependent on the size of the system, L, in comparison to a distance L-0, which is determined by the size of A(0), and gives rise to two fundamentally different types of sedimentary systems: a constrained system where L < L-0 and open systems where L > L-0. I derive simple expressions that show the dependence of the system response time on the system characteristics, such as its length, the size of the upstream catchment area, the amplitude of the incoming sedimentary flux and the respective rate parameters (diffusivity or erodibility) for each of the two models. I show that the xi-q model predicts longer response times. I demonstrate that although the manner in which signals propagates through the sedimentary system differs greatly between the two models, they both predict that perturbations that last longer than the response time of the system can be recorded in the stratigraphy of the sedimentary system and in particular of the fan. Interestingly, the xi-q model predicts that all perturbations in the incoming sedimentary flux will be transmitted through the system, whereas the TL model predicts that rapid perturbations cannot. I finally discuss why and under which conditions these differences are important and propose observational ways to determine which of the two models is most appropriate to represent natural systems.},
  language  = {en}
}
@article{HennigKuehn2021,
  author    = {Hennig, Theresa and K{\"u}hn, Michael},
  title     = {Potential uranium migration within the geochemical gradient of the opalinus clay system at the Mont Terri},
  series = {Minerals},
  volume    = {11},
  journal   = {Minerals},
  number    = {10},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2075-163X},
  doi       = {10.3390/min11101087},
  pages     = {22},
  year      = {2021},
  abstract  = {Transport properties of potential host rocks for nuclear waste disposal are typically determined in laboratory or in-situ experiments under geochemically controlled and constant conditions. Such a homogeneous assumption is no longer applicable on the host rock scale as can be seen from the pore water profiles of the potential host rock Opalinus Clay at Mont Terri (Switzerland). The embedding aquifers are the hydro-geological boundaries, that established gradients in the 210 m thick low permeable section through diffusive exchange over millions of years. Present-day pore water profiles were confirmed by a data-driven as well as by a conceptual scenario. Based on the modelled profiles, the influence of the geochemical gradient on uranium migration was quantified by comparing the distances after one million years with results of common homogeneous models. Considering the heterogeneous system, uranium migrated up to 24 m farther through the formation depending on the source term position within the gradient and on the partial pressure of carbon dioxide pCO2 of the system. Migration lengths were almost equal for single- and multicomponent diffusion. Differences can predominantly be attributed to changes in the sorption capacity, whereby pCO2 governs how strong uranium migration is affected by the geochemical gradient. Thus, the governing parameters for uranium migration in the Opalinus Clay can be ordered in descending priority: pCO2, geochemical gradients, mineralogical heterogeneity.</p>},
  language  = {en}
}
@article{LiSpangenbergSchicksetal.2022,
  author    = {Li, Zhen and Spangenberg, Erik and Schicks, Judith Maria and Kempka, Thomas},
  title     = {Numerical simulation of hydrate formation in the LArge-Scale Reservoir Simulator (LARS)},
  series = {Energies : open-access journal of related scientific research, technology development and studies in policy and management},
  volume    = {15},
  journal   = {Energies : open-access journal of related scientific research, technology development and studies in policy and management},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1996-1073},
  doi       = {10.3390/en15061974},
  pages     = {27},
  year      = {2022},
  abstract  = {The LArge-scale Reservoir Simulator (LARS) has been previously developed to study hydrate dissociation in hydrate-bearing systems under in-situ conditions. In the present study, a numerical framework of equations of state describing hydrate formation at equilibrium conditions has been elaborated and integrated with a numerical flow and transport simulator to investigate a multi-stage hydrate formation experiment undertaken in LARS. A verification of the implemented modeling framework has been carried out by benchmarking it against another established numerical code. Three-dimensional (3D) model calibration has been performed based on laboratory data available from temperature sensors, fluid sampling, and electrical resistivity tomography. The simulation results demonstrate that temperature profiles, spatial hydrate distribution, and bulk hydrate saturation are consistent with the observations. Furthermore, our numerical framework can be applied to calibrate geophysical measurements, optimize post-processing workflows for monitoring data, improve the design of hydrate formation experiments, and investigate the temporal evolution of sub-permafrost methane hydrate reservoirs.},
  language  = {en}
}
@article{KoertingKoellnerKurasetal.2021,
  author    = {K{\"o}rting, Friederike Magdalena and K{\"o}llner, Nicole and Kuras, Agnieszka and B{\"o}sche, Nina Kristin and Rogass, Christian and Mielke, Christian and Elger, Kirsten and Altenberger, Uwe},
  title     = {A solar optical hyperspectral library of rare-earth-bearing minerals, rare-earth oxide powders, copper-bearing minerals and Apliki mine surface samples},
  series = {Earth system science data : ESSD},
  volume    = {13},
  journal   = {Earth system science data : ESSD},
  publisher = {Copernics Publications},
  address   = {Katlenburg-Lindau},
  issn      = {1866-3508},
  doi       = {10.5194/essd-13-923-2021},
  pages     = {923 -- 942},
  year      = {2021},
  abstract  = {Mineral resource exploration and mining is an essential part of today's high-tech industry. Elements such as rare-earth elements (REEs) and copper are, therefore, in high demand. Modern exploration techniques from multiple platforms (e.g., spaceborne and airborne), to detect and map the spectral characteristics of the materials of interest, require spectral libraries as an essential reference. They include field and laboratory spectral information in combination with geochemical analyses for validation. Here, we present a collection of REE- and copper-related hyperspectral spectra with associated geochemical information. The libraries contain reflectance spectra from rare-earth element oxides, REE-bearing minerals, copper-bearing minerals and mine surface samples from the Apliki copper-gold-pyrite mine in the Republic of Cyprus. The samples were measured with the HySpex imaging spectrometers in the visible and near infrared (VNIR) and shortwave infrared (SWIR) range (400-2500 nm). The geochemical validation of each sample is provided with the reflectance spectra. The spectral libraries are openly available to assist future mineral mapping campaigns and laboratory spectroscopic analyses. The spectral libraries and corresponding geochemistry are published via GFZ Data Services with the following DOIs: https://doi.org/10.5880/GFZ.1.4.2019.004 (13 REE-bearing minerals and 16 oxide powders, Koerting et al., 2019a), https://doi.org/10.5880/GFZ.1.4.2019.003 (20 copper-bearing minerals, Koellner et al., 2019), and https://doi.org/10.5880/GFZ.1.4.2019.005 (37 copper-bearing surface material samples from the Apliki coppergold-pyrite mine in Cyprus, Koerting et al., 2019b). All spectral libraries are united and comparable by the internally consistent method of hyperspectral data acquisition in the laboratory.},
  language  = {en}
}
@article{LiSpangenbergSchicksetal.2022,
  author    = {Li, Zhen and Spangenberg, Erik and Schicks, Judith Maria and Kempka, Thomas},
  title     = {Numerical Simulation of Coastal Sub-Permafrost Gas Hydrate Formation in the Mackenzie Delta, Canadian Arctic},
  series = {Energies},
  volume    = {15},
  journal   = {Energies},
  number    = {14},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1996-1073},
  doi       = {10.3390/en15144986},
  pages     = {25},
  year      = {2022},
  abstract  = {The Mackenzie Delta (MD) is a permafrost-bearing region along the coasts of the Canadian Arctic which exhibits high sub-permafrost gas hydrate (GH) reserves. The GH occurring at the Mallik site in the MD is dominated by thermogenic methane (CH4), which migrated from deep conventional hydrocarbon reservoirs, very likely through the present fault systems. Therefore, it is assumed that fluid flow transports dissolved CH4 upward and out of the deeper overpressurized reservoirs via the existing polygonal fault system and then forms the GH accumulations in the Kugmallit-Mackenzie Bay Sequences. We investigate the feasibility of this mechanism with a thermo-hydraulic-chemical numerical model, representing a cross section of the Mallik site. We present the first simulations that consider permafrost formation and thawing, as well as the formation of GH accumulations sourced from the upward migrating CH4-rich formation fluid. The simulation results show that temperature distribution, as well as the thickness and base of the ice-bearing permafrost are consistent with corresponding field observations. The primary driver for the spatial GH distribution is the permeability of the host sediments. Thus, the hypothesis on GH formation by dissolved CH4 originating from deeper geological reservoirs is successfully validated. Furthermore, our results demonstrate that the permafrost has been substantially heated to 0.8-1.3 degrees C, triggered by the global temperature increase of about 0.44 degrees C and further enhanced by the Arctic Amplification effect at the Mallik site from the early 1970s to the mid-2000s.},
  language  = {en}
}
@article{HanKuhlicke2021,
  author    = {Han, Sungju and Kuhlicke, Christian},
  title     = {Barriers and drivers for mainstreaming nature-based solutions for flood risks},
  series = {International journal of disaster risk science},
  volume    = {12},
  journal   = {International journal of disaster risk science},
  number    = {5},
  publisher = {Springer},
  address   = {New York},
  issn      = {2095-0055},
  doi       = {10.1007/s13753-021-00372-4},
  pages     = {661 -- 672},
  year      = {2021},
  abstract  = {Nature-based solutions (NBS) are seen as a promising adaptation measure that sustainably deals with diverse societal challenges, while simultaneously delivering multiple benefits. Nature-based solutions have been highlighted as a resilient and sustainable means of mitigating floods and other hazards globally. This study examined diverging conceptualizations of NBS, as well as the attitudinal (for example, emotions and beliefs) and contextual (for example, legal and political aspects) barriers and drivers of NBS for flood risks in South Korea. Semistructured interviews were conducted with 11 experts and focused on the topic of flood risk measures and NBS case studies. The analysis found 11 barriers and five drivers in the attitudinal domain, and 13 barriers and two drivers in the contextual domain. Most experts see direct monetary benefits as an important attitudinal factor for the public. Meanwhile, the cost-effectiveness of NBS and their capacity to cope with flood risks were deemed influential factors that could lead decision makers to opt for NBS. Among the contextual factors, insufficient systems to integrate NBS in practice and the ideologicalization of NBS policy were found to be peculiar barriers, which hinder consistent realization of initiatives and a long-term national plan for NBS. Understanding the barriers and drivers related to the mainstreaming of NBS is critical if we are to make the most of such solutions for society and nature. It is also essential that we have a shared definition, expectation, and vision of NBS.},
  language  = {en}
}
@article{LoiblBookhagenValadeetal.2019,
  author    = {Loibl, David and Bookhagen, Bodo and Valade, Sebastien and Schneider, Christoph},
  title     = {OSARIS, the "Open Source SAR Investigation System" for Automatized Parallel InSAR Processing of Sentinel-1 Time Series Data With Special Emphasis on Cryosphere Applications},
  series = {Frontiers in Earth Science},
  volume    = {7},
  journal   = {Frontiers in Earth Science},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {2296-6463},
  doi       = {10.3389/feart.2019.00172},
  pages     = {20},
  year      = {2019},
  abstract  = {With the advent of the two Sentinel-1 (S1) satellites, Synthetic Aperture Radar (SAR) data with high temporal and spatial resolution are freely available. This provides a promising framework to facilitate detailed investigations of surface instabilities and movements on large scales with high temporal resolution, but also poses substantial processing challenges because of storage and computation requirements. Methods are needed to efficiently detect short term changes in dynamic environments. Approaches considering pair-wise processing of a series of consecutive scenes to retain maximum temporal resolution in conjunction with time series analyses are required. Here we present OSARIS, the "Open Source SAR Investigation System," as a framework to process large stacks of S1 data on high-performance computing clusters. Based on Generic Mapping Tools SAR, shell scripts, and the workload manager Slurm, OSARIS provides an open and modular framework combining parallelization of high-performance C programs, flexible processing schemes, convenient configuration, and generation of geocoded stacks of analysis-ready base data, including amplitude, phase, coherence, and unwrapped interferograms. Time series analyses can be conducted by applying automated modules to the data stacks. The capabilities of OSARIS are demonstrated in a case study from the northwestern Tien Shan, Central Asia. After merging of slices, a total of 80 scene pairs were processed from 174 total input scenes. The coherence time series exhibits pronounced seasonal variability, with relatively high coherence values prevailing during the summer months in the nival zone. As an example of a time series analysis module, we present OSARIS' "Unstable Coherence Metric" which identifies pixels affected by significant drops from high to low coherence values. Measurements of motion provided by LOSD measurements require careful evaluation because interferometric phase unwrapping is prone to errors. Here, OSARIS provides a series of modules to detect and mask unwrapping errors, correct for atmospheric disturbances, and remove large-scale trends. Wall clock processing time for the case study (area ~9,000 km2) was ~12 h 4 min on a machine with 400 cores and 2 TB RAM. In total, ~12 d 10 h 44 min (~96\%) were saved through parallelization. A comparison of selected OSARIS datasets to results from two state-of-the-art SAR processing suites, ISCE and SNAP, shows that OSARIS provides products of competitive quality despite its high level of automatization. OSARIS thus facilitates efficient S1-based region-wide investigations of surface movement events over multiple years.},
  language  = {en}
}
@article{DalleauKramerSchadtGangatetal.2019,
  author    = {Dalleau, Mayeul and Kramer-Schadt, Stephanie and Gangat, Yassine and Bourjea, Jerome and Lajoie, Gilles and Grimm, Volker},
  title     = {Modeling the emergence of migratory corridors and foraging hot spots of the green sea turtle},
  series = {Ecology and evolution},
  volume    = {9},
  journal   = {Ecology and evolution},
  number    = {18},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2045-7758},
  doi       = {10.1002/ece3.5552},
  pages     = {10317 -- 10342},
  year      = {2019},
  abstract  = {Environmental factors shape the spatial distribution and dynamics of populations. Understanding how these factors interact with movement behavior is critical for efficient conservation, in particular for migratory species. Adult female green sea turtles, Chelonia mydas, migrate between foraging and nesting sites that are generally separated by thousands of kilometers. As an emblematic endangered species, green turtles have been intensively studied, with a focus on nesting, migration, and foraging. Nevertheless, few attempts integrated these behaviors and their trade-offs by considering the spatial configurations of foraging and nesting grounds as well as environmental heterogeneity like oceanic currents and food distribution. We developed an individual-based model to investigate the impact of local environmental conditions on emerging migratory corridors and reproductive output and to thereby identify conservation priority sites. The model integrates movement, nesting, and foraging behavior. Despite being largely conceptual, the model captured realistic movement patterns which confirm field studies. The spatial distribution of migratory corridors and foraging hot spots was mostly constrained by features of the regional landscape, such as nesting site locations, distribution of feeding patches, and oceanic currents. These constraints also explained the mixing patterns in regional forager communities. By implementing alternative decision strategies of the turtles, we found that foraging site fidelity and nesting investment, two characteristics of green turtles' biology, are favorable strategies under unpredictable environmental conditions affecting their habitats. Based on our results, we propose specific guidelines for the regional conservation of green turtles as well as future research suggestions advancing spatial ecology of sea turtles. Being implemented in an easy to learn open-source software, our model can coevolve with the collection and analysis of new data on energy budget and movement into a generic tool for sea turtle research and conservation. Our modeling approach could also be useful for supporting the conservation of other migratory marine animals.},
  language  = {en}
}
@article{RegmiBookhagen2022,
  author    = {Regmi, Shakil and Bookhagen, Bodo},
  title     = {The spatial pattern of extreme precipitation from 40 years of gauge data in the central Himalaya},
  series = {Weather and climate extremes},
  volume    = {37},
  journal   = {Weather and climate extremes},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2212-0947},
  doi       = {10.1016/j.wace.2022.100470},
  pages     = {14},
  year      = {2022},
  abstract  = {The topography of the Himalaya exerts a substantial control on the spatial distribution of monsoonal rainfall, which is a vital water source for the regional economy and population. But the occurrence of short-lived and high-intensity precipitation results in socio-economic losses. This study relies on 40 years of daily data from 204 ground stations in Nepal to derive extreme precipitation thresholds, amounts, and days at the 95th percentile. We additionally determine the precipitation magnitude-frequency relation. We observe that extreme precipitation amounts follow an almost uniform band parallel to topographic contour lines in the southern Himalaya mountains in central and eastern Nepal but not in western Nepal. The relationship of extreme precipitation indices with topographic relief shows that extreme precipitation thresholds decrease with increasing elevation, but extreme precipitation days increase in higher elevation areas. Furthermore, stations above 1 km elevation exhibit a power-law relation in the rainfall magnitude-frequency framework. Stations at higher elevations generally have lower values of power-law exponents than low elevation areas. This suggests a fundamentally different behaviour of the rainfall distribution and an increased occurrence of extreme rainfall storms in the high elevation areas of Nepal.},
  language  = {en}
}
@article{StedingKempkaZirkleretal.2021,
  author    = {Steding, Svenja and Kempka, Thomas and Zirkler, Axel and K{\"u}hn, Michael},
  title     = {Spatial and temporal evolution of leaching zones within potash seams reproduced by reactive transport simulations},
  series = {Water / Molecular Diversity Preservation International (MDPI)},
  volume    = {13},
  journal   = {Water / Molecular Diversity Preservation International (MDPI)},
  number    = {2},
  publisher = {Molecular Diversity Preservation International},
  address   = {Basel},
  issn      = {2073-4441},
  doi       = {10.3390/w13020168},
  pages     = {21},
  year      = {2021},
  abstract  = {Leaching zones within potash seams generally represent a significant risk to subsurface mining operations and the construction of technical caverns in salt rocks, but their temporal and spatial formation has been investigated only rudimentarily to date. To the knowledge of the authors, current reactive transport simulation implementations are not capable to address hydraulic-chemical interactions within potash salt. For this reason, a reactive transport model has been developed and complemented by an innovative approach to calculate the interchange of minerals and solution at the water-rock interface. Using this model, a scenario analysis was carried out based on a carnallite-bearing potash seam. The results show that the evolution of leaching zones depends on the mineral composition and dissolution rate of the original salt rock, and that the formation can be classified by the dimensionless parameters of Peclet (Pe) and Damkohler (Da). For Pe > 2 and Da > 1, a funnel-shaped leaching zone is formed, otherwise the dissolution front is planar. Additionally, Da > 1 results in the formation of a sylvinitic zone and a flow barrier. Most scenarios represent hybrid forms of these cases. The simulated shapes and mineralogies are confirmed by literature data and can be used to assess the hazard potential.},
  language  = {en}
}
@article{FranzSudoKhomenko2022,
  author    = {Franz, Gerhard and Sudo, Masafumi and Khomenko, Vladimir},
  title     = {40Ar/39Ar dating of a hydrothermal pegmatitic buddingtonite-muscovite assemblage from Volyn, Ukraine},
  series = {European journal of mineralogy : EJM : an international journal on mineralogy, petrology, geochemistry, and related sciences},
  volume    = {34},
  journal   = {European journal of mineralogy : EJM : an international journal on mineralogy, petrology, geochemistry, and related sciences},
  number    = {1},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {0935-1221},
  doi       = {10.5194/ejm-34-7-2022},
  pages     = {7 -- 18},
  year      = {2022},
  abstract  = {We determined Ar-40/Ar-39 ages of buddingtonite, occurring together with muscovite, with the laser-ablation method. This is the first attempt to date the NH4-feldspar buddingtonite, which is typical for sedimentary-diagenetic environments of sediments, rich in organic matter, or in hydrothermal environments, associated with volcanic geyser systems. The sample is a hydrothermal breccia, coming from the Paleoproterozoic pegmatite field of the Korosten Plutonic Complex, Volyn, Ukraine. A detailed characterization by optical methods, electron microprobe analyses, backscattered electron imaging, and IR analyses showed that the buddingtonite consists of euhedral-appearing platy crystals of tens of micrometers wide, 100 or more micrometers in length, which consist of fine-grained fibers of <= 1 mu m thickness. The crystals are sector and growth zoned in terms of K-NH4-H3O content. The content of K allows for an age determination with the Ar-40/Ar-39 method, as well as in the accompanying muscovite, intimately intergrown with the buddingtonite. The determinations on muscovite yielded an age of 1491 +/- 9 Ma, interpreted as the hydrothermal event forming the breccia. However, buddingtonite apparent ages yielded a range of 563 +/- 14 Ma down to 383 +/- 12 Ma, which are interpreted as reset ages due to Ar loss of the fibrous buddingtonite crystals during later heating. We conclude that buddingtonite is suited for Ar-40/Ar-39 age determinations as a supplementary method, together with other methods and minerals; however, it requires a detailed mineralogical characterization, and the ages will likely represent minimum ages.},
  language  = {en}
}
@article{TranterDeLuciaWolfgrammetal.2020,
  author    = {Tranter, Morgan Alan and De Lucia, Marco and Wolfgramm, Markus and K{\"u}hn, Michael},
  title     = {Barite scale formation and injectivity loss models for geothermal systems},
  series = {Water},
  volume    = {12},
  journal   = {Water},
  number    = {11},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2073-4441},
  doi       = {10.3390/w12113078},
  pages     = {24},
  year      = {2020},
  abstract  = {Barite scales in geothermal installations are a highly unwanted effect of circulating deep saline fluids. They build up in the reservoir if supersaturated fluids are re-injected, leading to irreversible loss of injectivity. A model is presented for calculating the total expected barite precipitation. To determine the related injectivity decline over time, the spatial precipitation distribution in the subsurface near the injection well is assessed by modelling barite growth kinetics in a radially diverging Darcy flow domain. Flow and reservoir properties as well as fluid chemistry are chosen to represent reservoirs subject to geothermal exploration located in the North German Basin (NGB) and the Upper Rhine Graben (URG) in Germany. Fluids encountered at similar depths are hotter in the URG, while they are more saline in the NGB. The associated scaling amount normalised to flow rate is similar for both regions. The predicted injectivity decline after 10 years, on the other hand, is far greater for the NGB (64\%) compared to the URG (24\%), due to the temperature- and salinity-dependent precipitation rate. The systems in the NGB are at higher risk. Finally, a lightweight score is developed for approximating the injectivity loss using the Damkohler number, flow rate and total barite scaling potential. This formula can be easily applied to geothermal installations without running complex reactive transport simulations.},
  language  = {en}
}
@article{MikolajGuentnerBruninietal.2019,
  author    = {Mikolaj, Michal and G{\"u}ntner, Andreas and Brunini, Claudio and Wziontek, Hartmut and Gende, Mauricio and Schr{\"o}der, Stephan and Cassino, Augusto M. and Pasquare, Alfredo and Reich, Marvin and Hartmann, Anne and Oreiro, Fernando Ariel and Pendiuk, Jonathan and Guarracino, Luis and Antokoletz, Ezequiel D.},
  title     = {Hydrometeorological and gravity signals at the Argentine-German Geodetic Observatory (AGGO) in La Plata},
  series = {Earth system science data},
  volume    = {11},
  journal   = {Earth system science data},
  number    = {4},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1866-3508},
  doi       = {10.5194/essd-11-1501-2019},
  pages     = {1501 -- 1513},
  year      = {2019},
  abstract  = {The Argentine-German Geodetic Observatory (AGGO) is one of the very few sites in the Southern Hemisphere equipped with comprehensive cutting-edge geodetic instrumentation. The employed observation techniques are used for a wide range of geophysical applications. The data set provides gravity time series and selected gravity models together with the hydrometeorological monitoring data of the observatory. These parameters are of great interest to the scientific community, e.g. for achieving accurate realization of terrestrial and celestial reference frames. Moreover, the availability of the hydrometeorological products is beneficial to inhabitants of the region as they allow for monitoring of environmental changes and natural hazards including extreme events. The hydrological data set is composed of time series of groundwater level, modelled and observed soil moisture content, soil temperature, and physical soil properties and aquifer properties. The meteorological time series include air temperature, humidity, pressure, wind speed, solar radiation, precipitation, and derived reference evapotranspiration. These data products are extended by gravity models of hydrological, oceanic, La Plata estuary, and atmospheric effects. The quality of the provided meteorological time series is tested via comparison to the two closest WMO (World Meteorological Organization) sites where data are available only in an inferior temporal resolution. The hydrological series are validated by comparing the respective forward-modelled gravity effects to independent gravity observations reduced up to a signal corresponding to local water storage variation. Most of the time series cover the time span between April 2016 and November 2018 with either no or only few missing data points. The data set is available at https://doi.org/10.588/GFZ.5.4.2018.001 (Mikolaj et al., 2018).},
  language  = {en}
}
@article{SurminskiThieken2017,
  author    = {Surminski, Swenja and Thieken, Annegret},
  title     = {Promoting flood risk reduction},
  series = {Earth's Future},
  volume    = {5},
  journal   = {Earth's Future},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2328-4277},
  doi       = {10.1002/2017EF000587},
  pages     = {979 -- 1001},
  year      = {2017},
  abstract  = {Improving society's ability to prepare for, respond to and recover from flooding requires integrated, anticipatory flood risk management (FRM). However, most countries still focus their efforts on responding to flooding events if and when they occur rather than addressing their current and future vulnerability to flooding. Flood insurance is one mechanism that could promote a more ex ante approach to risk by supporting risk reduction activities. This paper uses an adapted version of Easton's System Theory to investigate the role of insurance for FRM in Germany and England. We introduce an anticipatory FRM framework, which allows flood insurance to be considered as part of a broader policy field. We analyze if and how flood insurance can catalyze a change toward a more anticipatory approach to FRM. In particular we consider insurance's role in influencing five key components of anticipatory FRM: risk knowledge, prevention through better planning, property\&\#8208;level protection measures, structural protection and preparedness (for response). We find that in both countries FRM is still a reactive, event\&\#8208;driven process, while anticipatory FRM remains underdeveloped. Collaboration between insurers and FRM decision\&\#8208;makers has already been successful, for example in improving risk knowledge and awareness, while in other areas insurance acts as a disincentive for more risk reduction action. In both countries there is evidence that insurance can play a significant role in encouraging anticipatory FRM, but this remains underutilized. Effective collaboration between insurers and government should not be seen as a cost, but as an investment to secure future insurability through flood resilience.},
  language  = {en}
}
@article{WutzlerHudsonThieken2022,
  author    = {Wutzler, Bianca and Hudson, Paul and Thieken, Annegret},
  title     = {Adaptation strategies of flood-damaged businesses in Germany},
  series = {Frontiers in water},
  volume    = {4},
  journal   = {Frontiers in water},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {2624-9375},
  doi       = {10.3389/frwa.2022.932061},
  pages     = {13},
  year      = {2022},
  abstract  = {Flood risk management in Germany follows an integrative approach in which both private households and businesses can make an important contribution to reducing flood damage by implementing property-level adaptation measures. While the flood adaptation behavior of private households has already been widely researched, comparatively less attention has been paid to the adaptation strategies of businesses. However, their ability to cope with flood risk plays an important role in the social and economic development of a flood-prone region. Therefore, using quantitative survey data, this study aims to identify different strategies and adaptation drivers of 557 businesses damaged by a riverine flood in 2013 and 104 businesses damaged by pluvial or flash floods between 2014 and 2017. Our results indicate that a low perceived self-efficacy may be an important factor that can reduce the motivation of businesses to adapt to flood risk. Furthermore, property-owners tended to act more proactively than tenants. In addition, high experience with previous flood events and low perceived response costs could strengthen proactive adaptation behavior. These findings should be considered in business-tailored risk communication.},
  language  = {en}
}
@article{VorogushynApelKemteretal.2022,
  author    = {Vorogushyn, Sergiy and Apel, Heiko and Kemter, Matthias and Thieken, Annegret},
  title     = {Analyse der Hochwassergef{\"a}hrdung im Ahrtal unter Ber{\"u}cksichtigung historischer Hochwasser},
  series = {Hydrologie und Wasserbewirtschaftung},
  volume    = {66},
  journal   = {Hydrologie und Wasserbewirtschaftung},
  number    = {5},
  publisher = {Bundesanst. f{\"u}r Gew{\"a}sserkunde},
  address   = {Koblenz},
  issn      = {1439-1783},
  doi       = {10.5675/HyWa_2022.5_2},
  pages     = {244 -- 254},
  year      = {2022},
  abstract  = {The flood disaster in July 2021 in western Germany calls for a critical discussion on flood hazard assessment, revision of flood hazard maps and communication of extreme flood scenarios. In the presented work, extreme value analysis was carried out for annual maximum peak flow series at the Altenahr gauge on the river Ahr. We compared flood statistics with and without considering historical flood events. An estimate for the return period of the recent flood based on the Generalized Extreme Value (GEV) distribution considering historical floods ranges between about 2600 and above 58700 years (90\% confidence interval) with a median of approximately 8600 years, whereas an estimate based on the 74-year long systematically recorded flow series would theoretically exceed 100 million years. Consideration of historical floods dramatically changes the flood quantiles that are used for the generation of official flood hazard maps. The fitting of the GEV to the time series with historical floods reveals, however, that the model potentially inadequately reflects the flood population. In this case, we might face a mixed sample, in which extreme floods result from very different processes compared to smaller floods. Hence, the probabilities of extreme floods could be much larger than those resulting from a single GEV model. The application of a process-based mixed flood distribution should be explored in future work. <br /> The comparison of the official HQextrem flood maps for the AhrValley with the inundation areas from July 2021 shows a striking discrepancy in the affected areas and calls for revision of design values used to define extreme flood scenarios. The hydrodynamic simulations of a 1000-year return period flood considering historical events and of the 1804 flood scenario compare much better to the flooded areas from July 2021, though both scenarios still underestimated the flood extent. <br /> Particular effects such as clogging of bridges and geomorphological changes of the river channel led to considerably larger flooded areas in July 2021 compared to the simulation results. Based on this analysis, we call for a consistent definition of HQextrem for flood hazard mapping in Germany, and suggest using high flood quantiles in the range of a 1,000-year flood. Flood maps should additionally include model-based reconstructions of the largest, reliably documented historical floods and/or synthetic worst-case scenarios. This would be an important step towards protecting potentially affected population and disaster management from surprises due to very rare and extreme flood events in future.},
  language  = {de}
}
@article{WilhelmsBoersigYangetal.2022,
  author    = {Wilhelms, Andre and B{\"o}rsig, Nicolas and Yang, Jingwei and Holbach, Andreas and Norra, Stefan},
  title     = {Insights into phytoplankton dynamics and water quality monitoring with the BIOFISH at the Elbe River, Germany},
  series = {Water},
  volume    = {14},
  journal   = {Water},
  number    = {13},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2073-4441},
  doi       = {10.3390/w14132078},
  pages     = {20},
  year      = {2022},
  abstract  = {Understanding the key factors influencing the water quality of large river systems forms an important basis for the assessment and protection of cross-regional ecosystems and the implementation of adapted water management concepts. However, identifying these factors requires in-depth comprehension of the unique environmental systems, which can only be achieved by detailed water quality monitoring. Within the scope of the joint science and sports event "Elbschwimmstaffel" (swimming relay on the river Elbe) in June/July 2017 organized by the German Ministry of Education and Research, water quality data were acquired along a 550 km long stretch of the Elbe River in Germany. During the survey, eight physiochemical water quality parameters were recorded in high spatial and temporal resolution with the BIOFISH multisensor system. Multivariate statistical methods were applied to identify and delineate processes influencing the water quality. The BIOFISH dataset revealed that phytoplankton activity has a major impact on the water quality of the Elbe River in the summer months. The results suggest that phytoplankton biomass constitutes a substantial proportion of the suspended particles and that photosynthetic activity of phytoplankton is closely related to significant temporal changes in pH and oxygen saturation. An evaluation of the BIOFISH data based on the combination of statistical analysis with weather and discharge data shows that the hydrological and meteorological history of the sampled water body was the main driver of phytoplankton dynamics. This study demonstrates the capacity of longitudinal river surveys with the BIOFISH or similar systems for water quality assessment, the identification of pollution sources and their utilization for online in situ monitoring of rivers.},
  language  = {en}
}
@article{KaiserGrosseBoikeetal.2021,
  author    = {Kaiser, Soraya and Grosse, Guido and Boike, Julia and Langer, Moritz},
  title     = {Monitoring the transformation of Arctic landscapes},
  series = {Remote sensing / Molecular Diversity Preservation International (MDPI)},
  volume    = {13},
  journal   = {Remote sensing / Molecular Diversity Preservation International (MDPI)},
  number    = {14},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2072-4292},
  doi       = {10.3390/rs13142802},
  pages     = {19},
  year      = {2021},
  abstract  = {Water bodies are a highly abundant feature of Arctic permafrost ecosystems and strongly influence their hydrology, ecology and biogeochemical cycling. While very high resolution satellite images enable detailed mapping of these water bodies, the increasing availability and abundance of this imagery calls for fast, reliable and automatized monitoring. This technical work presents a largely automated and scalable workflow that removes image noise, detects water bodies, removes potential misclassifications from infrastructural features, derives lake shoreline geometries and retrieves their movement rate and direction on the basis of ortho-ready very high resolution satellite imagery from Arctic permafrost lowlands. We applied this workflow to typical Arctic lake areas on the Alaska North Slope and achieved a successful and fast detection of water bodies. We derived representative values for shoreline movement rates ranging from 0.40-0.56 m yr(-1) for lake sizes of 0.10 ha-23.04 ha. The approach also gives an insight into seasonal water level changes. Based on an extensive quantification of error sources, we discuss how the results of the automated workflow can be further enhanced by incorporating additional information on weather conditions and image metadata and by improving the input database. The workflow is suitable for the seasonal to annual monitoring of lake changes on a sub-meter scale in the study areas in northern Alaska and can readily be scaled for application across larger regions within certain accuracy limitations.},
  language  = {en}
}
@article{KhuranaHesseHildebrandtetal.2022,
  author    = {Khurana, Swamini and Heße, Falk and Hildebrandt, Anke and Thullner, Martin},
  title     = {Predicting the impact of spatial heterogeneity on microbially mediated nutrient cycling in the subsurface},
  series = {Biogeosciences},
  volume    = {19},
  journal   = {Biogeosciences},
  number    = {3},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1726-4170},
  doi       = {10.5194/bg-19-665-2022},
  pages     = {665 -- 688},
  year      = {2022},
  abstract  = {The subsurface is a temporally dynamic and spatially heterogeneous compartment of the Earth's critical zone, and biogeochemical transformations taking place in this compartment are crucial for the cycling of nutrients. The impact of spatial heterogeneity on such microbially mediated nutrient cycling is not well known, which imposes a severe challenge in the prediction of in situ biogeochemical transformation rates and further of nutrient loading contributed by the groundwater to the surface water bodies. Therefore, we used a numerical modelling approach to evaluate the sensitivity of groundwater microbial biomass distribution and nutrient cycling to spatial heterogeneity in different scenarios accounting for various residence times. The model results gave us an insight into domain characteristics with respect to the presence of oxic niches in predominantly anoxic zones and vice versa depending on the extent of spatial heterogeneity and the flow regime. The obtained results show that microbial abundance, distribution, and activity are sensitive to the applied flow regime and that the mobile (i.e. observable by groundwater sampling) fraction of microbial biomass is a varying, yet only a small, fraction of the total biomass in a domain. Furthermore, spatial heterogeneity resulted in anaerobic niches in the domain and shifts in microbial biomass between active and inactive states. The lack of consideration of spatial heterogeneity, thus, can result in inaccurate estimation of microbial activity. In most cases this leads to an overestimation of nutrient removal (up to twice the actual amount) along a flow path. We conclude that the governing factors for evaluating this are the residence time of solutes and the Damkohler number (Da) of the biogeochemical reactions in the domain. We propose a relationship to scale the impact of spatial heterogeneity on nutrient removal governed by the logioDa. This relationship may be applied in upscaled descriptions of microbially mediated nutrient cycling dynamics in the subsurface thereby resulting in more accurate predictions of, for example, carbon and nitrogen cycling in groundwater over long periods at the catchment scale.},
  language  = {en}
}
@article{ChenChenSobeletal.2019,
  author    = {Chen, Xinwei and Chen, Hanlin and Sobel, Edward and Lin, Xiubin and Cheng, Xiaogan and Yan, Jiakai and Yang, Shaomei},
  title     = {Convergence of the Pamir and the South Tian Shan in the late Cenozoic},
  series = {Lithosphere},
  volume    = {11},
  journal   = {Lithosphere},
  number    = {4},
  publisher = {American Institute of Physics},
  address   = {Boulder},
  issn      = {1941-8264},
  doi       = {10.1130/L1028.1},
  pages     = {507 -- 523},
  year      = {2019},
  abstract  = {In response to collision and convergence between India and Asia during the Cenozoic, convergence took place between the Pamir and South Tian Shan. Here we present new detrital zircon U-Pb ages coupled with conglomerate clast counting and sedimentary data from the late Cenozoic Wuheshalu section in the convergence zone, to shed light on the convergence process of the Pamir and South Tian Shan. Large Triassic zircon U-Pb age populations in all seven samples suggest that Triassic igneous rocks from the North Pamir were the major source area for the late Cenozoic Wuheshalu section. In the Miocene, large populations of the North Pamir component supports rapid exhumation in the North Pamir and suggest that topography already existed there since the early Miocene. Exhumation of the South Tian Shan was relatively less important in the Miocene and its detritus could only reach a limited area in the foreland area. Gradually increasing sediment loading and convergence of the Pamir and South Tian Shan caused rapid subsidence in the convergence area. Since ca. 6-5.3 Ma, the combination of a major North Pamir component and a minor South Tian Shan component at the Wuheshalu section is consistent with active deformation of the South Tian Shan and the North Pamir. During deposition of the upper Atushi Formation, a larger proportion of North Pamir-derived sediments was deposited in the Wuheshalu section, maybe because faulting and northward propagation of the North Pamir caused northward displacement of the depocenter to north of the Wuheshalu section.},
  language  = {en}
}
@article{NennewitzThiedeBookhagen2018,
  author    = {Nennewitz, Markus and Thiede, Rasmus C. and Bookhagen, Bodo},
  title     = {Fault activity, tectonic segmentation, and deformation pattern of the western Himalaya on Ma timescales inferred from landscape morphology},
  series = {Lithosphere},
  volume    = {10},
  journal   = {Lithosphere},
  number    = {5},
  publisher = {American Institute of Physics},
  address   = {Boulder},
  issn      = {1941-8264},
  doi       = {10.1130/L681.1},
  pages     = {632 -- 640},
  year      = {2018},
  abstract  = {The location and magnitude of Himalayan tectonic activity has been debated for decades, and several aspects remain unknown. For instance, the spatial distribution of crustal shortening that ultimately sustains Himalayan topography and the activity of major fault zones remain unknown at Ma timescales. In this study, we address the spatial deformation pattern in the data-scarce western Himalaya. We calculated catchment averaged, normalized river-steepness indices of non-glaciated drainage basins with tributary catchment areas between 5 and 200 km(2) (n = 2138). We analyzed the spatial distribution of the relative change of river steepness both along and across strike to gain information about the regional distribution of differential uplift pattern and relate this to the activity of distinctive fault segments. For our study area, we observe a positive correlation of averaged k(sn) values with long-term exhumation rates derived from previously published thermochronologic datasets combined with thermal modeling as well as with millennial timescale denudation rates based on cosmogenic nuclide dating. Our results indicate three tectono-geomorphic segments with distinctive landscape morphology, structural architecture, and fault geometry along the western Himalaya: Garhwal-Sutlej, Chamba, and Kashmir Himalaya (from east to west). Moreover, our data recognize distinctive fault segments showing varying thrust activity along strike of the Main Frontal Thrust, the Main Boundary Thrust, and in the vicinity of the steep topographic transition between the Lesser and Greater Himalaya. In this region, we relate out-of-sequence deformation along major basement thrust ramps, such as the Munsiari Thrust with deformation along a mid-crustal ramp along the basal decollement. We suggest that during the Quaternary, all major fault zones in the Western Himalaya experienced out-of-sequence faulting and have accommodated some portion of crustal shortening.},
  language  = {en}
}
@article{TranterDeLuciaKuehn2021,
  author    = {Tranter, Morgan Alan and De Lucia, Marco and K{\"u}hn, Michael},
  title     = {Barite scaling potential modelled for fractured-porous geothermal reservoirs},
  series = {Minerals},
  volume    = {11},
  journal   = {Minerals},
  number    = {11},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2075-163X},
  doi       = {10.3390/min11111198},
  pages     = {22},
  year      = {2021},
  abstract  = {Barite scalings are a common cause of permanent formation damage to deep geothermal reservoirs. Well injectivity can be impaired because the ooling of saline fluids reduces the solubility of barite, and the continuous re-injection of supersaturated fluids forces barite to precipitate in the host rock. Stimulated reservoirs in the Upper Rhine Graben often have multiple relevant flow paths in the porous matrix and fracture zones, sometimes spanning multiple stratigraphical units to achieve the economically necessary injectivity. While the influence of barite scaling on injectivity has been investigated for purely porous media, the role of fractures within reservoirs consisting of both fractured and porous sections is still not well understood. Here, we present hydro-chemical simulations of a dual-layer geothermal reservoir to study the long-term impact of barite scale formation on well injectivity. Our results show that, compared to purely porous reservoirs, fractured porous reservoirs have a significantly reduced scaling risk by up to 50\%, depending on the flow rate ratio of fractures. Injectivity loss is doubled, however, if the amount of active fractures is increased by one order of magnitude, while the mean fracture aperture is decreased, provided the fractured aquifer dictates the injection rate. We conclude that fractured, and especially hydraulically stimulated, reservoirs are generally less affected by barite scaling and that large, but few, fractures are favourable. We present a scaling score for fractured-porous reservoirs, which is composed of easily derivable quantities such as the radial equilibrium length and precipitation potential. This score is suggested for use approximating the scaling potential and its impact on injectivity of a fractured-porous reservoir for geothermal exploitation.},
  language  = {en}
}
@article{OlatunjiKolawoleOloruntolaetal.2017,
  author    = {Olatunji, Akinade S. and Kolawole, Tesleem O. and Oloruntola, Moroof and G{\"u}nter, Christina},
  title     = {Evaluation of pollution of soils and particulate matter around metal recycling factories in Southwestern Nigeria},
  series = {Journal of health and pollutuin},
  volume    = {8},
  journal   = {Journal of health and pollutuin},
  number    = {17},
  publisher = {Blacksmith Institute and Pure Earth},
  address   = {New York},
  issn      = {2156-9614},
  doi       = {10.5696/2156-9614-8.17.20},
  pages     = {20 -- 30},
  year      = {2017},
  abstract  = {Background. Metal recycling factories (MRFs) have developed rapidly in Nigeria as recycling policies have been increasingly embraced. These MRFs are point sources for introducing potentially toxic elements (PTEs) into environmental media. Objectives. The aim of this study was to determine the constituents (elemental and mineralogy) of the wastes (slag and particulate matter, (PM)) and soils around the MRFs and to determine the level of pollution within the area. Methods. Sixty samples (30 slag samples, 15 soil samples and 15 PM samples) were collected for this study. The soils, slag and PM samples were analyzed for elemental constituents using inductively coupled plasma optical emission spectrometry. Mineralogy of the PM was determined using scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), and soil mineralogy was determined by an X-ray diffractometer (XRD). Results. The results of the soil analyses revealed the following concentrations for the selected metals in mg/kg include lead (Pb) (21.0-2399.0), zinc (Zn) (56.0-4188.0), copper (Cu) (10.0-1470.0), nickel (Ni) (6.0-215.0), chromium (Cr) (921.0-1737.0) and cadmium (Cd) (below detectable limit (Bdl)-18.1). For the slags the results were Pb (68.0-.333.0), Zn (1364.0-3062), Cu (119.0-1470.0), Ni (12.0-675.0), Cr (297-1737) and Cd (Bdl-15.8). The results in mu g/g for the metal analysis in PM were Pb (4.6-160.0), Zn (18.0-471.0), Cu (2.5-11.0), Ni (0.8-4.2), and Cr (2.5-11.0), while Cd was undetected. The slags are currently utilized for filling the foundations of buildings and roads, providing additional pathways for the introduction of PTEs into the environment from the suspended materials generated from mechanical breakdown of the slags. Conclusions. The MRFs were found to have impacted the quality of environmental media through the introduction of PTEs, impairing soil quality, in addition to PM, which can have detrimental health consequences. Further studies on the health implications of these pollutants and their impacts on human health are needed. Competing Interests. The authors declare no competing financial interests},
  language  = {en}
}
@article{JentschDuesingJolieetal.2021,
  author    = {Jentsch, Anna and D{\"u}sing, Walter and Jolie, Egbert and Zimmer, Martin},
  title     = {Monitoring the response of volcanic CO2 emissions to changes in the Los Humeros hydrothermal system},
  series = {Scientific reports},
  volume    = {11},
  journal   = {Scientific reports},
  number    = {1},
  publisher = {Macmillan Publishers Limited, part of Springer Nature},
  address   = {[London]},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-021-97023-x},
  pages     = {11},
  year      = {2021},
  abstract  = {Carbon dioxide is the most abundant, non-condensable gas in volcanic systems, released into the atmosphere through either diffuse or advective fluid flow. The emission of substantial amounts of CO2 at Earth's surface is not only controlled by volcanic plumes during periods of eruptive activity or fumaroles, but also by soil degassing along permeable structures in the subsurface. Monitoring of these processes is of utmost importance for volcanic hazard analyses, and is also relevant for managing geothermal resources. Fluid-bearing faults are key elements of economic value for geothermal power generation. Here, we describe for the first time how sensitively and quickly natural gas emissions react to changes within a deep hydrothermal system due to geothermal fluid reinjection. For this purpose, we deployed an automated, multi-chamber CO2 flux monitoring system within the damage zone of a deep-rooted major normal fault in the Los Humeros Volcanic Complex (LHVC) in Mexico and recorded data over a period of five months. After removing the atmospheric effects on variations in CO2 flux, we calculated correlation coefficients between residual CO2 emissions and reinjection rates, identifying an inverse correlation of rho = - 0.51 to - 0.66. Our results indicate that gas emissions respond to changes in reinjection rates within 24 h, proving an active hydraulic communication between the hydrothermal system and Earth's surface. This finding is a promising indication not only for geothermal reservoir monitoring but also for advanced long-term volcanic risk analysis. Response times allow for estimation of fluid migration velocities, which is a key constraint for conceptual and numerical modelling of fluid flow in fracture-dominated systems.},
  language  = {en}
}
@article{DeLuciaKuehnLindemannetal.2021,
  author    = {De Lucia, Marco and K{\"u}hn, Michael and Lindemann, Alexander and L{\"u}bke, Max and Schnor, Bettina},
  title     = {POET (v0.1): speedup of many-core parallel reactive transport simulations with fast DHT lookups},
  series = {Geoscientific model development : an interactive open access journal of the European Geosciences Union},
  volume    = {14},
  journal   = {Geoscientific model development : an interactive open access journal of the European Geosciences Union},
  number    = {12},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1991-959X},
  doi       = {10.5194/gmd-14-7391-2021},
  pages     = {7391 -- 7409},
  year      = {2021},
  abstract  = {Coupled reactive transport simulations are extremely demanding in terms of required computational power, which hampers their application and leads to coarsened and oversimplified domains. The chemical sub-process represents the major bottleneck: its acceleration is an urgent challenge which gathers increasing interdisciplinary interest along with pressing requirements for subsurface utilization such as spent nuclear fuel storage, geothermal energy and CO2 storage. In this context we developed POET (POtsdam rEactive Transport), a research parallel reactive transport simulator integrating algorithmic improvements which decisively speed up coupled simulations. In particular, POET is designed with a master/worker architecture, which ensures computational efficiency in both multicore and cluster compute environments. POET does not rely on contiguous grid partitions for the parallelization of chemistry but forms work packages composed of grid cells distant from each other. Such scattering prevents particularly expensive geochemical simulations, usually concentrated in the vicinity of a reactive front, from generating load imbalance between the available CPUs (central processing units), as is often the case with classical partitions. Furthermore, POET leverages an original implementation of the distributed hash table (DHT) mechanism to cache the results of geochemical simulations for further reuse in subsequent time steps during the coupled simulation. The caching is hence particularly advantageous for initially chemically homogeneous simulations and for smooth reaction fronts. We tune the rounding employed in the DHT on a 2D benchmark to validate the caching approach, and we evaluate the performance gain of POET's master/worker architecture and the DHT speedup on a 3D benchmark comprising around 650 000 grid elements. The runtime for 200 coupling iterations, corresponding to 960 simulation days, reduced from about 24 h on 11 workers to 29 min on 719 workers. Activating the DHT reduces the runtime further to 2 h and 8 min respectively. Only with these kinds of reduced hardware requirements and computational costs is it possible to realistically perform the longterm complex reactive transport simulations, as well as perform the uncertainty analyses required by pressing societal challenges connected with subsurface utilization.},
  language  = {en}
}
@article{BrillPassuniPinedaEspichanCuyaetal.2020,
  author    = {Brill, Fabio Alexander and Passuni Pineda, Silvia and Espichan Cuya, Bruno and Kreibich, Heidi},
  title     = {A data-mining approach towards damage modelling for El Nino events in Peru},
  series = {Geomatics, natural hazards and risk},
  volume    = {11},
  journal   = {Geomatics, natural hazards and risk},
  number    = {1},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {1947-5705},
  doi       = {10.1080/19475705.2020.1818636},
  pages     = {1966 -- 1990},
  year      = {2020},
  abstract  = {Compound natural hazards likeEl Ninoevents cause high damage to society, which to manage requires reliable risk assessments. Damage modelling is a prerequisite for quantitative risk estimations, yet many procedures still rely on expert knowledge, and empirical studies investigating damage from compound natural hazards hardly exist. A nationwide building survey in Peru after theEl Ninoevent 2017 - which caused intense rainfall, ponding water, flash floods and landslides - enables us to apply data-mining methods for statistical groundwork, using explanatory features generated from remote sensing products and open data. We separate regions of different dominant characteristics through unsupervised clustering, and investigate feature importance rankings for classifying damage via supervised machine learning. Besides the expected effect of precipitation, the classification algorithms select the topographic wetness index as most important feature, especially in low elevation areas. The slope length and steepness factor ranks high for mountains and canyons. Partial dependence plots further hint at amplified vulnerability in rural areas. An example of an empirical damage probability map, developed with a random forest model, is provided to demonstrate the technical feasibility.},
  language  = {en}
}
@article{HalamaGlodnyKonradSchmolkeetal.2018,
  author    = {Halama, Ralf and Glodny, Johannes and Konrad-Schmolke, Matthias and Sudo, Masafumi},
  title     = {Rb-Sr and in situ Ar-40/Ar-39 dating of exhumation-related shearing and fluid-induced recrystallization in the Sesia zone (Western Alps, Italy)},
  series = {Geosphere},
  volume    = {14},
  journal   = {Geosphere},
  number    = {4},
  publisher = {American Institute of Physics},
  address   = {Boulder},
  issn      = {1553-040X},
  doi       = {10.1130/GES01521.1},
  pages     = {1425 -- 1450},
  year      = {2018},
  abstract  = {The Sesia zone in the Italian Western Alps is a piece of continental crust that has been subducted to eclogite-facies conditions and records a complex metamorphic history. The exact timing of events and the significance of geochronological information are debated due to the interplay of tectonic, metamorphic, and metasomatic processes. Here we present new geochronological data using Rb-Sr internal mineral isochrons and in situ Ar-40/Ar-39 laser ablation data to provide constraints on the relative importance of fluid-mediated mineral replacement reactions and diffusion for the interpretation of radiogenic isotope signatures, and on the use of these isotopic systems for dating metamorphic and variably deformed rocks. Our study focuses on the shear zone at the contact between two major lithological units of the Sesia zone, the eclogitic micaschists and the gneiss minuti. Metasedimentary rocks of the eclogitic micaschists unit contain phengite with step-like zoning in major element chemistry as evidence for petrologic disequilibrium. Distinct Ar-40/Ar-39 spot ages of relict phengite cores and over-printed rims demonstrate the preservation of individual age domains in the crystals. The eclogitic micaschists also show systematic Sr isotope disequilibria among different phengite populations, so that minimum ages of relict assemblage crystallization can be differentiated from the timing of late increments of deformation. The preservation of these disequilibrium features shows the lack of diffusive re-equilibration and underpins that fluid-assisted dissolution and recrystallization reactions are the main factors controlling the isotope record in these subduction-related metamorphic rocks. Blueschist-facies mylonites record deformation along the major shear zone that separates the eclogitic micaschists from the gneiss minuti. Two Rb-Sr isochrones that comprise several white mica fractions and glaucophane constrain the timing of this deformation and accompanying near-complete blueschist-facies re-equilibration of the Rb-Sr system to 60.1 +/- 0.9 Ma and 60.9 +/- 2.1 Ma, respectively. Overlapping ages in eclogitic micaschists of 60.1 +/- 1.1 (Rb-Sr isochron of sheared matrix assemblage), 58.6 +/- 0.8, and 60.9 +/- 0.4 Ma (white mica Ar-40/Ar-39 inverse isochron ages) support the significance of this age and show that fluid-rock interaction and partial re-equilibration occurred as much as several kilometers away from the shear zone. An earlier equilibration during high-pressure conditions in the eclogitic mica schists is recorded in minimum Rb-Sr ages for relict assemblages (77.2 +/- 0.8 and 72.4 +/- 1.1 Ma) and an Ar-40/Ar-39 inverse isochron age of 75.4 +/- 0.8 Ma for white mica cores, again demonstrating that the two isotope systems provide mutually supporting geochronological information. Local reactivation and recrystallization along the shear zone lasted >15 m.y., as late increments of deformation are recorded in a greenschist-facies mylonite by a Rb-Sr isochron age of 46.5 +/- 0.7 Ma.},
  language  = {en}
}
@article{ZozulyaKullerudRibackietal.2020,
  author    = {Zozulya, Dmitry R. and Kullerud, Kare and Ribacki, Enrico and Altenberger, Uwe and Sudo, Masafumi and Savchenko, Yevgeny E.},
  title     = {The newly discovered neoproterozoic aillikite occurrence in Vinoren (Southern Norway)},
  series = {Minerals},
  volume    = {10},
  journal   = {Minerals},
  number    = {11},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2075-163X},
  doi       = {10.3390/min10111029},
  pages     = {26},
  year      = {2020},
  abstract  = {During the period 750-600 Ma ago, prior to the final break-up of the supercontinent Rodinia, the crust of both the North American Craton and Baltica was intruded by significant amounts of rift-related magmas originating from the mantle. In the Proterozoic crust of Southern Norway, the 580 Ma old Fen carbonatite-ultramafic complex is a representative of this type of rocks. In this paper, we report the occurrence of an ultramafic lamprophyre dyke which possibly is linked to the Fen complex, although Ar-40/Ar-39 data from phenocrystic phlogopite from the dyke gave an age of 686 +/- 9 Ma. The lamprophyre dyke was recently discovered in one of the Kongsberg silver mines at Vinoren, Norway. Whole rock geochemistry, geochronological and mineralogical data from the ultramafic lamprophyre dyke are presented aiming to elucidate its origin and possible geodynamic setting. From the whole-rock composition of the Vinoren dyke, the rock could be recognized as transitional between carbonatite and kimberlite-II (orangeite). From its diagnostic mineralogy, the rock is classified as aillikite. The compositions and xenocrystic nature of several of the major and accessory minerals from the Vinoren aillikite are characteristic for diamondiferous rocks (kimberlites/lamproites/UML): Phlogopite with kinoshitalite-rich rims, chromite-spinel-ulvospinel series, Mg- and Mn-rich ilmenites, rutile and lucasite-(Ce). We suggest that the aillikite melt formed during partial melting of a MARID (mica-amphibole-rutile-ilmenite-diopside)-like source under CO2 fluxing. The pre-rifting geodynamic setting of the Vinoren aillikite before the Rodinia supercontinent breakup suggests a relatively thick SCLM (Subcontinental Lithospheric Mantle) during this stage and might indicate a diamond-bearing source for the parental melt. This is in contrast to the about 100 Ma younger Fen complex, which were derived from a thin SCLM.},
  language  = {en}
}
@article{RiedlMelnickNjueetal.2022,
  author    = {Riedl, Simon and Melnick, Daniel and Njue, Lucy and Sudo, Masafumi and Strecker, Manfred},
  title     = {Mid-Pleistocene to recent crustal extension in the inner graben of the Northern Kenya Rift},
  series = {Geochemistry, geophysics, geosystems},
  volume    = {23},
  journal   = {Geochemistry, geophysics, geosystems},
  number    = {3},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {1525-2027},
  doi       = {10.1029/2021GC010123},
  pages     = {25},
  year      = {2022},
  abstract  = {Magmatic continental rifts often constitute nascent plate boundaries, yet long-term extension rates and transient rate changes associated with these early stages of continental breakup remain difficult to determine. Here, we derive a time-averaged minimum extension rate for the inner graben of the Northern Kenya Rift (NKR) of the East African Rift System for the last 0.5 m.y. We use the TanDEM-X science digital elevation model to evaluate fault-scarp geometries and determine fault throws across the volcano-tectonic axis of the inner graben of the NKR. Along rift-perpendicular profiles, amounts of cumulative extension are determined, and by integrating four new Ar-40/Ar-39 radiometric dates for the Silali volcano into the existing geochronology of the faulted volcanic units, time-averaged extension rates are calculated. This study reveals that in the inner graben of the NKR, the long-term extension rate based on mid-Pleistocene to recent brittle deformation has minimum values of 1.0-1.6 mm yr(-1), locally with values up to 2.0 mm yr(-1). A comparison with the decadal, geodetically determined extension rate reveals that at least 65\% of the extension must be accommodated within a narrow, 20-km-wide zone of the inner rift. In light of virtually inactive border faults of the NKR, we show that extension is focused in the region of the active volcano-tectonic axis in the inner graben, thus highlighting the maturing of continental rifting in the NKR.},
  language  = {en}
}
@article{KrmičekTimmermanZiemannetal.2020,
  author    = {Krm{\´i}ček, Luk{\´a}š and Timmerman, Martin Jan and Ziemann, Martin Andreas and Sudo, Masafumi and Ulrych, Jaromir},
  title     = {40Ar/39Ar step-heating dating of phlogopite and kaersutite megacrysts from the Železn{\´a} hůrka (Eisenb{\"u}hl) Pleistocene scoria cone, Czech Republic},
  series = {Geologica Carpathica},
  volume    = {71},
  journal   = {Geologica Carpathica},
  number    = {4},
  publisher = {Veda},
  address   = {Bratislava},
  issn      = {1335-0552},
  doi       = {10.31577/GeolCarp.71.4.6},
  pages     = {382 -- 387},
  year      = {2020},
  abstract  = {(40)A/Ar-39 step-heating of mica and amphibole megacrysts from hauyne-bearing olivine melilitite scoria/tephra from the Zelezna hurka yielded a 435 +/- 108 ka isotope correlation age for phlogopite and a more imprecise 1.55 Ma total gas age of the kaersutite megacryst. The amphibole megacrysts may constitute the first, and the younger phlogopite megacrysts the later phase of mafic, hydrous melilitic magma crystallization. It cannot be ruled out that the amphibole megacrysts are petrogenetically unrelated to tephra and phlogopite megacrysts and were derived from mantle xenoliths or disaggregated older, deep crustal pegmatites. This is in line both with the rarity of amphibole at Zelezna hurka and with the observed signs of magmatic resorption at the edges of amphibole crystals.},
  language  = {en}
}
@article{LandholmPradhanWegmannetal.2019,
  author    = {Landholm, David M. and Pradhan, Prajal and Wegmann, Peter and Romero Sanchez, Miguel Antonio and Suarez Salazar, Juan Carlos and Kropp, J{\"u}rgen},
  title     = {Reducing deforestation and improving livestock productivity: greenhouse gas mitigation potential of silvopastoral systems in Caqueta},
  series = {Environmental research letters},
  volume    = {14},
  journal   = {Environmental research letters},
  number    = {11},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {1748-9326},
  doi       = {10.1088/1748-9326/ab3db6},
  pages     = {12},
  year      = {2019},
  abstract  = {Colombia's agriculture, forestry and other land use sector accounts for nearly half of its total greenhouse gas (GHG) emissions. The importance of smallholder deforestation is comparatively high in relation to its regional counterparts, and livestock agriculture represents the largest driver of primary forest depletion. Silvopastoral systems (SPSs) are presented as agroecological solutions that synergistically enhance livestock productivity, improve local farmers' livelihoods and hold the potential to reduce pressure on forest conversion. The department of Caquet{\´a} represents Colombia's most important deforestation hotspot. Targeting smallholder livestock farms through survey data, in this work we investigate the GHG mitigation potential of implementing SPSs for smallholder farms in this region. Specifically, we assess whether the carbon sequestration taking place in the soil and biomass of SPSs is sufficient to offset the per-hectare increase in livestock GHG emissions resulting from higher stocking rates. To address these questions we use data on livestock population characteristics and historic land cover changes reported from a survey covering 158 farms and model the carbon sequestration occurring in three different scenarios of progressively-increased SPS complexity using the CO2 fix model. We find that, even with moderate tree planting densities, the implementation of SPSs can reduce GHG emissions by 2.6 Mg CO2e ha-1 yr-1 in relation to current practices, while increasing agriculture productivity and contributing to the restoration of severely degraded landscapes.},
  language  = {en}
}
@article{KriewaldPradhanCostaetal.2019,
  author    = {Kriewald, Steffen and Pradhan, Prajal and Costa, Lu{\´i}s F{\´i}l{\´i}pe Carvalho da and Ros, Anselmo Garcia Cantu and Kropp, J{\"u}rgen},
  title     = {Hungry cities: how local food self-sufficiency relates to climate change, diets, and urbanisation},
  series = {Environmental research letters},
  volume    = {14},
  journal   = {Environmental research letters},
  number    = {9},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {1748-9326},
  doi       = {10.1088/1748-9326/ab2d56},
  pages     = {9},
  year      = {2019},
  abstract  = {Using a newly developed model approach and combining it with remote sensing, population, and climate data, first insights are provided into how local diets, urbanisation, and climate change relates to local urban food self-sufficiency. In plain terms, by utilizing the global peri-urban (PU) food production potential approximately lbn urban residents (30\% of global urban population) can be locally nourished, whereby further urbanisation is by far the largest pressure factor on PU agriculture, followed by a change of diets, and climate change. A simple global food transport model which optimizes transport and neglects differences in local emission intensities indicates that CO2 emissions related to food transport can be reduced by a factor of 10.},
  language  = {en}
}
@article{PradhanCostaRybskietal.2017,
  author    = {Pradhan, Prajal and Costa, Lu{\´i}s F{\´i}l{\´i}pe Carvalho da and Rybski, Diego and Lucht, Wolfgang and Kropp, J{\"u}rgen},
  title     = {A Systematic Study of Sustainable Development Goal (SDG) Interactions},
  series = {Earths Future},
  volume    = {5},
  journal   = {Earths Future},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2328-4277},
  doi       = {10.1002/2017EF000632},
  pages     = {1169 -- 1179},
  year      = {2017},
  abstract  = {Sustainable development goals (SDGs) have set the 2030 agenda to transform our world by tackling multiple challenges humankind is facing to ensure well-being, economic prosperity, and environmental protection. In contrast to conventional development agendas focusing on a restricted set of dimensions, the SDGs provide a holistic and multidimensional view on development. Hence, interactions among the SDGs may cause diverging results. To analyze the SDG interactions we systematize the identification of synergies and trade-offs using official SDG indicator data for 227 countries. A significant positive correlation between a pair of SDG indicators is classified as a synergy while a significant negative correlation is classified as a trade-off. We rank synergies and trade-offs between SDGs pairs on global and country scales in order to identify the most frequent SDG interactions. For a given SDG, positive correlations between indicator pairs were found to outweigh the negative ones in most countries. Among SDGs the positive and negative correlations between indicator pairs allowed for the identification of particular global patterns. SDG 1 (No poverty) has synergetic relationship with most of the other goals, whereas SDG 12 (Responsible consumption and production) is the goal most commonly associated with trade-offs. The attainment of the SDG agenda will greatly depend on whether the identified synergies among the goals can be leveraged. In addition, the highlighted trade-offs, which constitute obstacles in achieving the SDGs, need to be negotiated and made structurally nonobstructive by deeper changes in the current strategies.},
  language  = {en}
}
@article{RibeiroRybskiKropp2019,
  author    = {Ribeiro, Haroldo V. and Rybski, Diego and Kropp, J{\"u}rgen},
  title     = {Effects of changing population or density on urban carbon dioxide emissions},
  series = {Nature Communications},
  volume    = {10},
  journal   = {Nature Communications},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2041-1723},
  doi       = {10.1038/s41467-019-11184-y},
  pages     = {9},
  year      = {2019},
  abstract  = {The question of whether urbanization contributes to increasing carbon dioxide emissions has been mainly investigated via scaling relationships with population or population density. However, these approaches overlook the correlations between population and area, and ignore possible interactions between these quantities. Here, we propose a generalized framework that simultaneously considers the effects of population and area along with possible interactions between these urban metrics. Our results significantly improve the description of emissions and reveal the coupled role between population and density on emissions. These models show that variations in emissions associated with proportionate changes in population or density may not only depend on the magnitude of these changes but also on the initial values of these quantities. For US areas, the larger the city, the higher is the impact of changing its population or density on its emissions; but population changes always have a greater effect on emissions than population density.},
  language  = {en}
}
@article{BastianRobelSchmidtetal.2021,
  author    = {Bastian, Philipp U. and Robel, Nathalie and Schmidt, Peter and Schrumpf, Tim and G{\"u}nter, Christina and Roddatis, Vladimir and Kumke, Michael U.},
  title     = {Resonance energy transfer to track the motion of lanthanide ions},
  series = {Biosensors : open access journal},
  volume    = {11},
  journal   = {Biosensors : open access journal},
  number    = {12},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2079-6374},
  doi       = {10.3390/bios11120515},
  pages     = {23},
  year      = {2021},
  abstract  = {The imagination of clearly separated core-shell structures is already outdated by the fact, that the nanoparticle core-shell structures remain in terms of efficiency behind their respective bulk material due to intermixing between core and shell dopant ions. In order to optimize the photoluminescence of core-shell UCNP the intermixing should be as small as possible and therefore, key parameters of this process need to be identified. In the present work the Ln(III) ion migration in the host lattices NaYF4 and NaGdF4 was monitored. These investigations have been performed by laser spectroscopy with help of lanthanide resonance energy transfer (LRET) between Eu(III) as donor and Pr(III) or Nd(III) as acceptor. The LRET is evaluated based on the Forster theory. The findings corroborate the literature and point out the migration of ions in the host lattices. Based on the introduced LRET model, the acceptor concentration in the surrounding of one donor depends clearly on the design of the applied core-shell-shell nanoparticles. In general, thinner intermediate insulating shells lead to higher acceptor concentration, stronger quenching of the Eu(III) donor and subsequently stronger sensitization of the Pr(III) or the Nd(III) acceptors. The choice of the host lattice as well as of the synthesis temperature are parameters to be considered for the intermixing process.},
  language  = {en}
}
@article{BoehnkeKrehlMoermannetal.2022,
  author    = {B{\"o}hnke, Denise and Krehl, Alice and Moermann, Kai and Volk, Rebekka and L{\"u}tzkendorf, Thomas and Naber, Elias and Becker, Ronja and Norra, Stefan},
  title     = {Mapping urban green and its ecosystem services at microscale-a methodological approach for climate adaptation and biodiversity},
  series = {Sustainability / Multidisciplinary Digital Publishing Institute (MDPI)},
  volume    = {14},
  journal   = {Sustainability / Multidisciplinary Digital Publishing Institute (MDPI)},
  number    = {15},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2071-1050},
  doi       = {10.3390/su14159029},
  pages     = {26},
  year      = {2022},
  abstract  = {The current awareness of the high importance of urban green leads to a stronger need for tools to comprehensively represent urban green and its benefits. A common scientific approach is the development of urban ecosystem services (UES) based on remote sensing methods at the city or district level. Urban planning, however, requires fine-grained data that match local management practices. Hence, this study linked local biotope and tree mapping methods to the concept of ecosystem services. The methodology was tested in an inner-city district in SW Germany, comparing publicly accessible areas and non-accessible courtyards. The results provide area-specific [m(2)] information on the green inventory at the microscale, whereas derived stock and UES indicators form the basis for comparative analyses regarding climate adaptation and biodiversity. In the case study, there are ten times more micro-scale green spaces in private courtyards than in the public space, as well as twice as many trees. The approach transfers a scientific concept into municipal planning practice, enables the quantitative assessment of urban green at the microscale and illustrates the importance for green stock data in private areas to enhance decision support in urban development. Different aspects concerning data collection and data availability are critically discussed.},
  language  = {en}
}
@article{DegenSpoonerScheckWenderothetal.2021,
  author    = {Degen, Denise and Spooner, Cameron and Scheck-Wenderoth, Magdalena and Cacace, Mauro},
  title     = {How biased are our models?},
  series = {Geoscientific model development : an interactive open access journal of the European Geosciences Union},
  volume    = {14},
  journal   = {Geoscientific model development : an interactive open access journal of the European Geosciences Union},
  number    = {11},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1991-959X},
  doi       = {10.5194/gmd-14-7133-2021},
  pages     = {7133 -- 7153},
  year      = {2021},
  abstract  = {Geophysical process simulations play a crucial role in the understanding of the subsurface. This understanding is required to provide, for instance, clean energy sources such as geothermal energy. However, the calibration and validation of the physical models heavily rely on state measurements such as temperature. In this work, we demonstrate that focusing analyses purely on measurements introduces a high bias. This is illustrated through global sensitivity studies. The extensive exploration of the parameter space becomes feasible through the construction of suitable surrogate models via the reduced basis method, where the bias is found to result from very unequal data distribution. We propose schemes to compensate for parts of this bias. However, the bias cannot be entirely compensated. Therefore, we demonstrate the consequences of this bias with the example of a model calibration.},
  language  = {en}
}
@article{RodriguezPicedaScheckWenderothBottetal.2022,
  author    = {Rodriguez Piceda, Constanza and Scheck-Wenderoth, Magdalena and Bott, Judith and Gomez Dacal, Maria Laura and Cacace, Mauro and Pons, Michael and Prezzi, Claudia and Strecker, Manfred},
  title     = {Controls of the Lithospheric Thermal Field of an Ocean-Continent Subduction Zone},
  series = {Lithosphere / Geological Society of America},
  volume    = {2022},
  journal   = {Lithosphere / Geological Society of America},
  number    = {1},
  publisher = {GeoScienceWorld},
  address   = {McLean},
  issn      = {1941-8264},
  doi       = {10.2113/2022/2237272},
  pages     = {26},
  year      = {2022},
  abstract  = {In an ocean-continent subduction zone, the assessment of the lithospheric thermal state is essential to determine the controls of the deformation within the upper plate and the dip angle of the subducting lithosphere. In this study, we evaluate the degree of influence of both the configuration of the upper plate (i.e., thickness and composition of the rock units) and variations of the subduction angle on the lithospheric thermal field of the southern Central Andes (29 degrees-39 degrees S). Here, the subduction angle increases from subhorizontal (5 degrees) north of 33 degrees S to steep (similar to 30 degrees) in the south. We derived the 3D temperature and heat flow distribution of the lithosphere in the southern Central Andes considering conversion of S wave tomography to temperatures together with steady-state conductive thermal modeling. We found that the orogen is overall warmer than the forearc and the foreland and that the lithosphere of the northern part of the foreland appears colder than its southern counterpart. Sedimentary blanketing and the thickness of the radiogenic crust exert the main control on the shallow thermal field (<50km depth). Specific conditions are present where the oceanic slab is relatively shallow (<85 km depth) and the radiogenic crust is thin. This configuration results in relatively colder temperatures compared to regions where the radiogenic crust is thick and the slab is steep. At depths >50km, the temperatures of the overriding plate are mainly controlled by the mantle heat input and the subduction angle. The thermal field of the upper plate likely preserves the flat subduction angle and influences the spatial distribution of shortening.},
  language  = {en}
}