@article{KutzschbachWunderKrstulovicetal.2016, author = {Kutzschbach, Martin and Wunder, Bernd and Krstulovic, Marija and Ertl, Andreas and Trumbull, Robert B. and Rocholl, Alexander and Giester, Gerald}, title = {First high-pressure synthesis of rossmanitic tourmaline and evidence for the incorporation of Li at the X site}, series = {Physics and chemistry of minerals / in cooperation with the International Mineralogical Association (IMA)}, volume = {44}, journal = {Physics and chemistry of minerals / in cooperation with the International Mineralogical Association (IMA)}, publisher = {Springer}, address = {New York}, issn = {0342-1791}, doi = {10.1007/s00269-016-0863-0}, pages = {353 -- 363}, year = {2016}, abstract = {Lithium is an important component of some tourmalines, especially in chemically evolved granites and pegmatites. All attempts at synthesizing Li-rich tourmaline have so far been unsuccessful. Here we describe the first synthesis of rossmanitic tourmaline at 4 GPa and 700 degrees C in the system Li2OAl2O3SiO2B2O3H2O (LASBH) from seed-free solid starting materials consisting of a homogenous mixture of Li2O, gamma-Al2O3, quartz and H3BO3. The solid run products after 12-day run duration comprise rossmanitic tourmaline (68 wt\%), dumortierite (28 wt\%) and traces of spodumene (3 wt\%) and coesite (1 wt\%). Tourmaline forms idiomorphic, large prismatic crystals (30 X 100 mu m), which are inclusion free and chemically unzoned. The refined cell dimensions of the tourmaline are: a = 15.7396(9) angstrom, c = 7.0575(5) angstrom, V = 1514.1(2) angstrom 3. Conventionally, the Li+ ion is assumed to exclusively occupy the octahedral Y site in the tourmaline structure to a maximum of 2 Li per formula unit (pfu). However, the chemical composition of our synthetic tourmaline determined by electron microprobe and secondary ion mass spectroscopy results in the formula: (X)(square Li-0.67(11)(0.33(11)))(Y)(Al2.53(10)Li0.47(10))(Z)(Al-6)T(Si5.42(15)B0.58(15))O-18(B)(BO3)(3)(V+W)[(OH)(2.40(3))O-1.60(3)], wherein a significant amount of Li occupies the X site for charge balance requirements. Reliable assignment of the OH-stretching vibrations in a polarized single-crystal Raman spectrum such as a single-crystal XRD structure refinement, confirms the incorporation of Li at the X site [0.24(9) and 0.15(5) Li-X pfu, respectively]. The SREF data show that the LiO1 distances are shortened significantly in order to compensate for the smaller ionic radius of Li+ compared to Na+, K+ or Ca2+ at the X site, i.e., Li is closer to the Si6O18 ring and to a sevenfold coordination with oxygen.}, language = {en} } @article{KornhuberPetoukhovPetrietal.2016, author = {Kornhuber, Kai and Petoukhov, Vladimir and Petri, Stefan and Rahmstorf, Stefan and Coumou, Dim}, title = {Evidence for wave resonance as a key mechanism for generating high-amplitude quasi-stationary waves in boreal summer}, series = {Climate dynamics : observational, theoretical and computational research on the climate system}, volume = {49}, journal = {Climate dynamics : observational, theoretical and computational research on the climate system}, publisher = {Springer}, address = {New York}, issn = {0930-7575}, doi = {10.1007/s00382-016-3399-6}, pages = {1961 -- 1979}, year = {2016}, abstract = {Several recent northern hemisphere summer extremes have been linked to persistent high-amplitude wave patterns (e.g. heat waves in Europe 2003, Russia 2010 and in the US 2011, Floods in Pakistan 2010 and Europe 2013). Recently quasi-resonant amplification (QRA) was proposed as a mechanism that, when certain dynamical conditions are fulfilled, can lead to such high-amplitude wave events. Based on these resonance conditions a detection scheme to scan reanalysis data for QRA events in boreal summer months was implemented. With this objective detection scheme we analyzed the occurrence and duration of QRA events and the associated atmospheric flow patterns in 1979-2015 reanalysis data. We detect a total number of 178 events for wave 6, 7 and 8 and find that during roughly one-third of all high amplitude events QRA conditions were met for respective waves. Our analysis reveals a significant shift for quasi-stationary waves 6 and 7 towards high amplitudes during QRA events, lagging first QRA-detection by typically one week. The results provide further evidence for the validity of the QRA hypothesis and its important role in generating high amplitude waves in boreal summer.}, language = {en} } @article{GonschorekLangerBernhardtetal.2016, author = {Gonschorek, Julia and Langer, Anja and Bernhardt, Benjamin and Raebiger, Caroline}, title = {Big Data in the Field of Civil Security Research: Approaches for the Visual Preprocessing of Fire Brigade Operations}, series = {Science}, volume = {7}, journal = {Science}, publisher = {IGI Global}, address = {Hershey}, issn = {1947-3192}, doi = {10.4018/IJAEIS.2016010104}, pages = {54 -- 64}, year = {2016}, abstract = {This article gives insight in a running dissertation at the University in Potsdam. Point of discussion is the spatial and temporal distribution of emergencies of German fire brigades that have not sufficiently been scientifically examined. The challenge is seen in Big Data: enormous amounts of data that exist now (or can be collected in the future) and whose variables are linked to one another. These analyses and visualizations can form a basis for strategic, operational and tactical planning, as well as prevention measures. The user-centered (geo-) visualization of fire brigade data accessible to the general public is a scientific contribution to the research topic 'geovisual analytics and geographical profiling'. It may supplement antiquated methods such as the so-called pinmaps as well as the areas of engagement that are freehand constructions in GIS. Considering police work, there are already numerous scientific projects, publications, and software solutions designed to meet the specific requirements of Crime Analysis and Crime Mapping. By adapting and extending these methods and techniques, civil security research can be tailored to the needs of fire departments. In this paper, a selection of appropriate visualization methods will be presented and discussed.}, language = {en} } @article{LangerwischWalzRammigetal.2016, author = {Langerwisch, Fanny and Walz, Ariane and Rammig, Anja and Tietjen, Britta and Thonicke, Kirsten and Cramer, Wolfgang}, title = {Deforestation in Amazonia impacts riverine carbon dynamics}, series = {Earth system dynamics}, volume = {7}, journal = {Earth system dynamics}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {2190-4979}, doi = {10.5194/esd-7-953-2016}, pages = {953 -- 968}, year = {2016}, abstract = {Fluxes of organic and inorganic carbon within the Amazon basin are considerably controlled by annual flooding, which triggers the export of terrigenous organic material to the river and ultimately to the Atlantic Ocean. The amount of carbon imported to the river and the further conversion, transport and export of it depend on temperature, atmospheric CO2, terrestrial productivity and carbon storage, as well as discharge. Both terrestrial productivity and discharge are influenced by climate and land use change. The coupled LPJmL and RivCM model system (Langerwisch et al., 2016) has been applied to assess the combined impacts of climate and land use change on the Amazon riverine carbon dynamics. Vegetation dynamics (in LPJmL) as well as export and conversion of terrigenous carbon to and within the river (RivCM) are included. The model system has been applied for the years 1901 to 2099 under two deforestation scenarios and with climate forcing of three SRES emission scenarios, each for five climate models. We find that high deforestation (business-as-usual scenario) will strongly decrease (locally by up to 90 \%) riverine particulate and dissolved organic carbon amount until the end of the current century. At the same time, increase in discharge leaves net carbon transport during the first decades of the century roughly unchanged only if a sufficient area is still forested. After 2050 the amount of transported carbon will decrease drastically. In contrast to that, increased temperature and atmospheric CO2 concentration determine the amount of riverine inorganic carbon stored in the Amazon basin. Higher atmospheric CO2 concentrations increase riverine inorganic carbon amount by up to 20\% (SRES A2). The changes in riverine carbon fluxes have direct effects on carbon export, either to the atmosphere via outgassing or to the Atlantic Ocean via discharge. The outgassed carbon will increase slightly in the Amazon basin, but can be regionally reduced by up to 60\% due to deforestation. The discharge of organic carbon to the ocean will be reduced by about 40\% under the most severe deforestation and climate change scenario. These changes would have local and regional consequences on the carbon balance and habitat characteristics in the Amazon basin itself as well as in the adjacent Atlantic Ocean.}, language = {en} } @article{NitzeGrosse2016, author = {Nitze, Ingmar and Grosse, Guido}, title = {Detection of landscape dynamics in the Arctic Lena Delta with temporally dense Landsat time-series stacks}, series = {Remote sensing of environment : an interdisciplinary journal}, volume = {181}, journal = {Remote sensing of environment : an interdisciplinary journal}, publisher = {Elsevier}, address = {New York}, issn = {0034-4257}, doi = {10.1016/j.rse.2016.03.038}, pages = {27 -- 41}, year = {2016}, abstract = {Arctic permafrost landscapes are among the most vulnerable and dynamic landscapes globally, but due to their extent and remoteness most of the landscape changes remain unnoticed. In order to detect disturbances in these areas we developed an automated processing chain for the calculation and analysis of robust trends of key land surface indicators based on the full record of available Landsat TM, ETM +, and OLI data. The methodology was applied to the similar to 29,000 km(2) Lena Delta in Northeast Siberia, where robust trend parameters (slope, confidence intervals of the slope, and intercept) were calculated for Tasseled Cap Greenness, Wetness and Brightness, NDVI, and NDWI, and NDMI based on 204 Landsat scenes for the observation period between 1999 and 2014. The resulting datasets revealed regional greening trends within the Lena Delta with several localized hot-spots of change, particularly in the vicinity of the main river channels. With a 30-m spatial resolution various permafrost-thaw related processes and disturbances, such as thermokarst lake expansion and drainage, fluvial erosion, and coastal changes were detected within the Lena Delta region, many of which have not been noticed or described before. Such hotspots of permafrost change exhibit significantly different trend parameters compared to non-disturbed areas. The processed dataset, which is made freely available through the data archive PANGAEA, will be a useful resource for further process specific analysis by researchers and land managers. With the high level of automation and the use of the freely available Landsat archive data, the workflow is scalable and transferrable to other regions, which should enable the comparison of land surface changes in different permafrost affected regions and help to understand and quantify permafrost landscape dynamics. (C) 2016 Elsevier Inc. All rights reserved.}, language = {en} } @article{RybskiReusserWinzetal.2016, author = {Rybski, Diego and Reusser, Dominik Edwin and Winz, Anna-Lena and Fichtner, Christina and Sterzel, Till and Kropp, J{\"u}rgen}, title = {Cities as nuclei of sustainability?}, series = {Environment and Planning B: Urban Analytics and City Science}, volume = {44}, journal = {Environment and Planning B: Urban Analytics and City Science}, number = {3}, publisher = {Sage Publ.}, address = {London}, issn = {2399-8083}, doi = {10.1177/0265813516638340}, pages = {425 -- 440}, year = {2016}, abstract = {We have assembled CO2 emission figures from collections of urban GHG emission estimates published in peer-reviewed journals or reports from research institutes and non-governmental organizations. Analyzing the scaling with population size, we find that the exponent is development dependent with a transition from super- to sub-linear scaling. From the climate change mitigation point of view, the results suggest that urbanization is desirable in developed countries. Further, we compare this analysis with a second scaling relation, namely the fundamental allometry between city population and area, and propose that density might be a decisive quantity too. Last, we derive the theoretical country-wide urban emissions by integration and obtain a dependence on the size of the largest city.}, language = {en} }