@article{RamachandranRupakhetiCherianetal.2022, author = {Ramachandran, Srikanthan and Rupakheti, Maheswar and Cherian, R. and Lawrence, Mark}, title = {Climate Benefits of Cleaner Energy Transitions in East and South Asia Through Black Carbon Reduction}, series = {Frontiers in environmental science}, volume = {10}, journal = {Frontiers in environmental science}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-665X}, doi = {10.3389/fenvs.2022.842319}, pages = {16}, year = {2022}, abstract = {The state of air pollution has historically been tightly linked to how we produce and use energy. Air pollutant emissions over Asia are now changing rapidly due to cleaner energy transitions; however, magnitudes of benefits for climate and air quality remain poorly quantified. The associated risks involve adverse health impacts, reduced agricultural yields, reduced freshwater availability, contributions to climate change, and economic costs. We focus particularly on climate benefits of energy transitions by making first-time use of two decades of high quality observations of atmospheric loading of light-absorbing black carbon (BC) over Kanpur (South Asia) and Beijing (East Asia) and relating these observations to changing energy, emissions, and economic trends in India and China. Our analysis reveals that absorption aerosol optical depth (AAOD) due to BC has decreased substantially, by 40\% over Kanpur and 60\% over Beijing between 2001 and 2017, and thus became decoupled from regional economic growth. Furthermore, the resultant decrease in BC emissions and BC AAOD over Asia is regionally coherent and occurs primarily due to transitions into cleaner energies (both renewables and fossil fuels) and not due to the decrease in primary energy supply or decrease in use of fossil use and biofuels and waste. Model simulations show that BC aerosols alone contribute about half of the surface temperature change (warming) of the total forcing due to greenhouse gases, natural and internal variability, and aerosols, thus clearly revealing the climate benefits due to a reduction in BC emissions, which would significantly reduce global warming. However, this modeling study excludes responses from natural variability, circulation, and sea ice responses, which cause relatively strong temperature fluctuations that may mask signals from BC aerosols. Our findings show additional benefits for climate (beyond benefits of CO2 reduction) and for several other issues of sustainability over South and East Asia, provide motivation for ongoing cleaner energy production, and consumption transitions, especially when they are associated with reduced emissions of air pollutants. Such an analysis connecting the trends in energy transitions and aerosol absorption loading, unavailable so far, is crucial for simulating the aerosol climate impacts over Asia which is quite uncertain.}, language = {en} } @phdthesis{Meijer2020, author = {Meijer, Niels}, title = {Asian dust, monsoons and westerlies during the Eocene}, doi = {10.25932/publishup-48868}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-488687}, school = {Universit{\"a}t Potsdam}, pages = {ix, 155}, year = {2020}, abstract = {The East Asian monsoons characterize the modern-day Asian climate, yet their geological history and driving mechanisms remain controversial. The southeasterly summer monsoon provides moisture, whereas the northwesterly winter monsoon sweeps up dust from the arid Asian interior to form the Chinese Loess Plateau. The onset of this loess accumulation, and therefore of the monsoons, was thought to be 8 million years ago (Ma). However, in recent years these loess records have been extended further back in time to the Eocene (56-34 Ma), a period characterized by significant changes in both the regional geography and global climate. Yet the extent to which these reconfigurations drive atmospheric circulation and whether the loess-like deposits are monsoonal remains debated. In this thesis, I study the terrestrial deposits of the Xining Basin previously identified as Eocene loess, to derive the paleoenvironmental evolution of the region and identify the geological processes that have shaped the Asian climate. I review dust deposits in the geological record and conclude that these are commonly represented by a mix of both windblown and water-laid sediments, in contrast to the pure windblown material known as loess. Yet by using a combination of quartz surface morphologies, provenance characteristics and distinguishing grain-size distributions, windblown dust can be identified and quantified in a variety of settings. This has important implications for tracking aridification and dust-fluxes throughout the geological record. Past reversals of Earth's magnetic field are recorded in the deposits of the Xining Basin and I use these together with a dated volcanic ash layer to accurately constrain the age to the Eocene period. A combination of pollen assemblages, low dust abundances and other geochemical data indicates that the early Eocene was relatively humid suggesting an intensified summer monsoon due to the warmer greenhouse climate at this time. A subsequent shift from predominantly freshwater to salt lakes reflects a long-term aridification trend possibly driven by global cooling and the continuous uplift of the Tibetan Plateau. Superimposed on this aridification are wetter intervals reflected in more abundant lake deposits which correlate with highstands of the inland proto-Paratethys Sea. This sea covered the Eurasian continent and thereby provided additional moisture to the winter-time westerlies during the middle to late Eocene. The long-term aridification culminated in an abrupt shift at 40 Ma reflected by the onset of windblown dust, an increase in steppe-desert pollen, the occurrence of high-latitude orbital cycles and northwesterly winds identified in deflated salt deposits. Together, these indicate the onset of a Siberian high atmospheric pressure system driving the East Asian winter monsoon as well as dust storms and was triggered by a major sea retreat from the Asian interior. These results therefore show that the proto-Paratethys Sea, though less well recognized than the Tibetan Plateau and global climate, has been a major driver in setting up the modern-day climate in Asia.}, language = {en} } @article{KayaDupontNivetProustetal.2019, author = {Kaya, Mustafa Y{\"u}cel and Dupont-Nivet, Guillaume and Proust, Jean-No{\"e}l and Roperch, Pierrick and Bougeois, Laurie and Meijer, Niels and Frieling, Joost and Fioroni, Chiara and Altiner, Sevin{\c{c}} {\"O}zkan and Vardar, Ezgi and Barbolini, Natasha and Stoica, Marius and Aminov, Jovid and Mamtimin, Mehmut and Zhaojie, Guo}, title = {Paleogene evolution and demise of the proto-Paratethys Sea in Central Asia (Tarim and Tajik basins)}, series = {Basin research}, volume = {31}, journal = {Basin research}, number = {3}, publisher = {Wiley}, address = {Hoboken}, issn = {0950-091X}, doi = {10.1111/bre.12330}, pages = {461 -- 486}, year = {2019}, abstract = {The proto-Paratethys Sea covered a vast area extending from the Mediterranean Tethys to the Tarim Basin in western China during Cretaceous and early Paleogene. Climate modelling and proxy studies suggest that Asian aridification has been governed by westerly moisture modulated by fluctuations of the proto-Paratethys Sea. Transgressive and regressive episodes of the proto-Paratethys Sea have been previously recognized but their timing, extent and depositional environments remain poorly constrained. This hampers understanding of their driving mechanisms (tectonic and/or eustatic) and their contribution to Asian aridification. Here, we present a new chronostratigraphic framework based on biostratigraphy and magnetostratigraphy as well as a detailed palaeoenvironmental analysis for the Paleogene proto-Paratethys Sea incursions in the Tajik and Tarim basins. This enables us to identify the major drivers of marine fluctuations and their potential consequences on Asian aridification. A major regional restriction event, marked by the exceptionally thick (<= 400 m) shelf evaporites is assigned a Danian-Selandian age (ca. 63-59 Ma) in the Aertashi Formation. This is followed by the largest recorded proto-Paratethys Sea incursion with a transgression estimated as early Thanetian (ca. 59-57 Ma) and a regression within the Ypresian (ca. 53-52 Ma), both within the Qimugen Formation. The transgression of the next incursion in the Kalatar and Wulagen formations is now constrained as early Lutetian (ca. 47-46 Ma), whereas its regression in the Bashibulake Formation is constrained as late Lutetian (ca. 41 Ma) and is associated with a drastic increase in both tectonic subsidence and basin infilling. The age of the final and least pronounced sea incursion restricted to the westernmost margin of the Tarim Basin is assigned as Bartonian-Priabonian (ca. 39.7-36.7 Ma). We interpret the long-term westward retreat of the proto-Paratethys Sea starting at ca. 41 Ma to be associated with far-field tectonic effects of the Indo-Asia collision and Pamir/Tibetan plateau uplift. Short-term eustatic sea level transgressions are superimposed on this long-term regression and seem coeval with the transgression events in the other northern Peri-Tethyan sedimentary provinces for the 1st and 2nd sea incursions. However, the 3rd sea incursion is interpreted as related to tectonism. The transgressive and regressive intervals of the proto-Paratethys Sea correlate well with the reported humid and arid phases, respectively in the Qaidam and Xining basins, thus demonstrating the role of the proto-Paratethys Sea as an important moisture source for the Asian interior and its regression as a contributor to Asian aridification.}, language = {en} } @article{GerlitzSteirouSchneideretal.2019, author = {Gerlitz, Lars and Steirou, Eva and Schneider, Christoph and Moron, Vincent and Vorogushyn, Sergiy and Merz, Bruno}, title = {Variability of the Cold Season Climate in Central Asia. Part II: Hydroclimatic Predictability}, series = {Journal of climate}, volume = {32}, journal = {Journal of climate}, number = {18}, publisher = {American Meteorological Soc.}, address = {Boston}, issn = {0894-8755}, doi = {10.1175/JCLI-D-18-0892.1}, pages = {6015 -- 6033}, year = {2019}, abstract = {Central Asia (CA) is subjected to a large variability of precipitation. This study presents a statistical model, relating precipitation anomalies in three subregions of CA in the cold season (November-March) with various predictors in the preceding October. Promising forecast skill is achieved for two subregions covering 1) Uzbekistan, Turkmenistan, Kyrgyzstan, Tajikistan, and southern Kazakhstan and 2) Iran, Afghanistan, and Pakistan. ENSO in October is identified as the major predictor. Eurasian snow cover and the quasi-biennial oscillation further improve the forecast performance. To understand the physical mechanisms, an analysis of teleconnections between these predictors and the wintertime circulation over CA is conducted. The correlation analysis of predictors and large-scale circulation indices suggests a seasonal persistence of tropical circulation modes and a dynamical forcing of the westerly circulation by snow cover variations over Eurasia. An EOF analysis of pressure and humidity patterns allows separating the circulation variability over CA into westerly and tropical modes and confirms that the identified predictors affect the respective circulation characteristics. Based on the previously established weather type classification for CA, the predictors are investigated with regard to their effect on the regional circulation. The results suggest a modification of the Hadley cell due to ENSO variations, with enhanced moisture supply from the Arabian Gulf during El Nino. They further indicate an influence of Eurasian snow cover on the wintertime Arctic Oscillation (AO) and Northern Hemispheric Rossby wave tracks. Positive anomalies favor weather types associated with dry conditions, while negative anomalies promote the formation of a quasi-stationary trough over CA, which typically occurs during positive AO conditions.}, 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 = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {703}, issn = {1866-8372}, doi = {10.25932/publishup-42787}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427873}, 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{GaubertPatelVeronetal.2016, author = {Gaubert, Philippe and Patel, Riddhi P. and Veron, Geraldine and Goodman, Steven M. and Willsch, Maraike and Vasconcelos, Raquel and Lourenco, Andre and Sigaud, Marie and Justy, Fabienne and Joshi, Bheem Dutt and Fickel, J{\"o}rns and Wilting, Andreas}, title = {Phylogeography of the Small Indian Civet and Origin of Introductions to Western Indian Ocean Islands}, series = {The journal of heredity : official journal of the American Genetic Association}, volume = {108}, journal = {The journal of heredity : official journal of the American Genetic Association}, publisher = {Oxford Univ. Press}, address = {Cary}, issn = {0022-1503}, doi = {10.1093/jhered/esw085}, pages = {270 -- 279}, year = {2016}, abstract = {The biogeographic dynamics affecting the Indian subcontinent, East and Southeast Asia during the Plio-Pleistocene has generated complex biodiversity patterns. We assessed the molecular biogeography of the small Indian civet (Viverricula indica) through mitogenome and cytochrome b + control region sequencing of 89 historical and modern samples to (1) establish a time-calibrated phylogeography across the species' native range and (2) test introduction scenarios to western Indian Ocean islands. Bayesian phylogenetic analyses identified 3 geographic lineages (East Asia, sister-group to Southeast Asia and the Indian subcontinent + northern Indochina) diverging 3.2-2.3 million years ago (Mya), with no clear signature of past demographic expansion. Within Southeast Asia, Balinese populations separated from the rest 2.6-1.3 Mya. Western Indian Ocean populations were assigned to the Indian subcontinent + northern Indochina lineage and had the lowest mitochondrial diversity. Approximate Bayesian computation did not distinguish between single versus multiple introduction scenarios. The early diversification of the small Indian civet was likely shaped by humid periods in the Late Pliocene-Early Pleistocene that created evergreen rainforest barriers, generating areas of intra-specific endemism in the Indian subcontinent, East, and Southeast Asia. Later, Pleistocene dispersals through drier conditions in South and Southeast Asia were likely, giving rise to the species' current natural distribution. Our molecular data supported the delineation of only 4 subspecies in V. indica, including an endemic Balinese lineage. Our study also highlighted the influence of prefirst millennium AD introductions to western Indian Ocean islands, with Indian and/or Arab traders probably introducing the species for its civet oil.}, language = {en} } @article{GhodsShabanianBergmanetal.2015, author = {Ghods, Abdolreza and Shabanian, Esmaeil and Bergman, Eric and Faridi, Mohammad and Donner, Stefanie and Mortezanejad, Gholamreza and Aziz-Zanjani, Asiyeh}, title = {The Varzaghan-Ahar, Iran, Earthquake Doublet (M-w 6.4, 6.2): implications for the geodynamics of northwest Iran}, series = {Geophysical journal international}, volume = {203}, journal = {Geophysical journal international}, number = {1}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0956-540X}, doi = {10.1093/gji/ggv306}, pages = {522 -- 540}, year = {2015}, abstract = {On 2012 August 11, a pair of large, damaging earthquakes struck the Varzaghan-Ahar region in northwest Iran, in a region where there was no major mapped fault or any well-documented historical seismicity. To investigate the active tectonics of the source region we applied a combination of seismological methods (local aftershock network, calibrated multiple event relocation and focal mechanism studies), field observations (structural geology and geomorphological) and inversions for the regional stress field. The epicentral region is north of the North Tabriz Fault. The first main shock is characterized by right-lateral strike-slip motion on an almost E-W fault plane of about 23 km length extending from the surface to a depth of about 14 km. The second main shock occurred on an ENE-striking fault that dips at 60-70A degrees to the NW. Independent inversions of focal mechanisms and geologically determined fault kinematic data for the active stress state yield a transpressional tectonic regime with sigma(1) oriented N132E. For the region northeast of the North Tabriz Fault, the presence of rigid lithosphere of the South Caspian Basin implies the kinematic adjustment by northward transferring of the contracted masses through both distributed deformation and structural deflections. Our results suggest that the kinematic adjustment inside a contracting wedge may occur along interacting crosswise or conjugate faults to accommodate low rates of internal deformation. At a global scale, our results indicate that despite the basic assumption of 'rigid blocks' in geodetic plate modelling, internal deformation of block-like regions could control the kinematics of deformation and the level of seismic hazard within and around such regions of low deformation rate.}, language = {en} } @article{RohrmannHeermanceKappetal.2013, author = {Rohrmann, Alexander and Heermance, Richard and Kapp, Paul and Cai, Fulong}, title = {Wind as the primary driver of erosion in the Qaidam Basin, China}, series = {Earth \& planetary science letters}, volume = {374}, journal = {Earth \& planetary science letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-821X}, doi = {10.1016/j.epsl.2013.03.011}, pages = {1 -- 10}, year = {2013}, abstract = {Deserts are a major source of loess and may undergo substantial wind-erosion as evidenced by yardang fields, deflation pans, and wind-scoured bedrock landscapes. However, there are few quantitative estimates of bedrock removal by wind abrasion and deflation. Here, we report wind-erosion rates in the western Qaidam Basin in central China based on measurements of cosmogenic Be-10 in exhumed Miocene sedimentary bedrock. Sedimentary bedrock erosion rates range from 0.05 to 0.4 mm/yr, although the majority of measurements cluster at 0.125 +/- 0.05 mm/yr. These results, combined with previous work, indicate that strong winds, hyper-aridity, exposure of friable Neogene strata, and ongoing rock deformation and uplift in the western Qaidam Basin have created an environment where wind, instead of water, is the dominant agent of erosion and sediment transport. Its geographic location (upwind) combined with volumetric estimates suggest that the Qaidam Basin is a major source (up to 50\%) of dust to the Chinese Loess Plateau to the east. The cosmogenically derived wind erosion rates are within the range of erosion rates determined from glacial and fluvial dominated landscapes worldwide, exemplifying the effectiveness of wind to erode and transport significant quantities of bedrock.}, language = {en} } @article{BraeuerAschHofstetteretal.2012, author = {Braeuer, B. and Asch, G{\"u}nter and Hofstetter, Rami and Haberland, Christian and Jaser, Darweesh and El-Kelani, Radwan J.. and Weber, Michael H.}, title = {Microseismicity distribution in the southern Dead Sea basin and its implications on the structure of the basin}, series = {Geophysical journal international}, volume = {188}, journal = {Geophysical journal international}, number = {3}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {0956-540X}, doi = {10.1111/j.1365-246X.2011.05318.x}, pages = {873 -- 878}, year = {2012}, abstract = {While the Dead Sea basin has been studied for a long time, the available knowledge about the detailed seismicity distribution in the area, as well as the deeper structure of the basin, is limited. Therefore, within the framework of the international project DESIRE (DEad Sea Integrated REsearch project), a dense temporary local seismological network was operated in the southern Dead Sea area. We use 530 local earthquakes, having all together 26 730 P- and S-arrival times for a simultaneous inversion of 1-D velocity models, station corrections and precise earthquake locations. Jackknife tests suggest an accuracy of the derived hypocentre locations of about 1 km. Thus, the result is the first clear image of the absolute distribution of the microseismicity of the area, especially in depth. The seismicity is concentrated in the upper crust down to 20 km depth while the lower limit of the seismicity is reached at 31 km depth. The seismic events at the eastern boundary fault (EBF) in the southern part of the study area represent the northward transform motion of the Arabian Plate along the Dead Sea Transform. North of the Boqeq fault the seismic activity represents the transfer of the motion in the pull-apart basin from the eastern to the western boundary. We find that from the surface downward the seismic events are tracing the boundary faults of the basin. The western boundary is mapped down to 12 km depth while the EBF reaches about 17 km depth, forming an asymmetric basin. One fifth of the data set is related to a specific cluster in time and space, which occurred in 2007 February at the western border fault. This cluster is aligned vertically, that is, it is perpendicular to the direction of the dominating left-lateral strike-slip movement at the main transform fault.}, language = {en} }