@phdthesis{Aichner2009,
  author    = {Aichner, Bernhard},
  title     = {Aquatic macrophyte-derived biomarkers as palaeolimnological proxies on the Tibetan Plateau},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-42095},
  school      = {Universit{\"a}t Potsdam},
  year      = {2009},
  abstract  = {The Tibetan Plateau is the largest elevated landmass in the world and profoundly influences atmospheric circulation patterns such as the Asian monsoon system. Therefore this area has been increasingly in focus of palaeoenvironmental studies. This thesis evaluates the applicability of organic biomarkers for palaeolimnological purposes on the Tibetan Plateau with a focus on aquatic macrophyte-derived biomarkers. Submerged aquatic macrophytes have to be considered to significantly influence the sediment organic matter due to their high abundance in many Tibetan lakes. They can show highly 13C-enriched biomass because of their carbon metabolism and it is therefore crucial for the interpretation of δ13C values in sediment cores to understand to which extent aquatic macrophytes contribute to the isotopic signal of the sediments in Tibetan lakes and in which way variations can be explained in a palaeolimnological context. Additionally, the high abundance of macrophytes makes them interesting as potential recorders of lake water δD. Hydrogen isotope analysis of biomarkers is a rapidly evolving field to reconstruct past hydrological conditions and therefore of special relevance on the Tibetan Plateau due to the direct linkage between variations of monsoon intensity and changes in regional precipitation / evaporation balances. A set of surface sediment and aquatic macrophyte samples from the central and eastern Tibetan Plateau was analysed for composition as well as carbon and hydrogen isotopes of n-alkanes. It was shown how variable δ13C values of bulk organic matter and leaf lipids can be in submerged macrophytes even of a single species and how strongly these parameters are affected by them in corresponding sediments. The estimated contribution of the macrophytes by means of a binary isotopic model was calculated to be up to 60\% (mean: 40\%) to total organic carbon and up to 100\% (mean: 66\%) to mid-chain n-alkanes. Hydrogen isotopes of n-alkanes turned out to record δD of meteoric water of the summer precipitation. The apparent enrichment factor between water and n-alkanes was in range of previously reported ones (≈-130 per mille) at the most humid sites, but smaller (average: -86 per mille) at sites with a negative moisture budget. This indicates an influence of evaporation and evapotranspiration on δD of source water for aquatic and terrestrial plants. The offset between δD of mid- and long-chain n-alkanes was close to zero in most of the samples, suggesting that lake water as well as soil and leaf water are affected to a similar extent by those effects. To apply biomarkers in a palaeolimnological context, the aliphatic biomarker fraction of a sediment core from Lake Koucha (34.0° N; 97.2° E; eastern Tibetan Plateau) was analysed for concentrations, δ13C and δD values of compounds. Before ca. 8 cal ka BP, the lake was dominated by aquatic macrophyte-derived mid-chain n-alkanes, while after 6 cal ka BP high concentrations of a C20 highly branched isoprenoid compound indicate a predominance of phytoplankton. Those two principally different states of the lake were linked by a transition period with high abundances of microbial biomarkers. δ13C values were relatively constant for long-chain n-alkanes, while mid-chain n-alkanes showed variations between -23.5 to -12.6 per mille. Highest values were observed for the assumed period of maximum macrophyte growth during the late glacial and for the phytoplankton maximum during the middle and late Holocene. Therefore, the enriched values were interpreted to be caused by carbon limitation which in turn was induced by high macrophyte and primary productivity, respectively. Hydrogen isotope signatures of mid-chain n-alkanes have been shown to be able to track a previously deduced episode of reduced moisture availability between ca. 10 and 7 cal ka BP, indicated by a 20 per mille shift towards higher δD values. Indications for cooler episodes at 6.0, 3.1 and 1.8 cal ka BP were gained from drops of biomarker concentrations, especially microbial-derived hopanoids, and from coincidental shifts towards lower δ13C values. Those episodes correspond well with cool events reported from other locations on the Tibetan Plateau as well as in the Northern Hemisphere. To conclude, the study of recent sediments and plants improved the understanding of factors affecting the composition and isotopic signatures of aliphatic biomarkers in sediments. Concentrations and isotopic signatures of the biomarkers in Lake Koucha could be interpreted in a palaeolimnological context and contribute to the knowledge about the history of the lake. Aquatic macrophyte-derived mid-chain n-alkanes were especially useful, due to their high abundance in many Tibetan Lakes and their ability to record major changes of lake productivity and palaeo-hydrological conditions. Therefore, they have the potential to contribute to a fuller understanding of past climate variability in this key region for atmospheric circulation systems.},
  language  = {en}
}
@phdthesis{Barsch2003,
  author    = {Barsch, Andreas},
  title     = {Zum Einfluss von Witterung und Klima auf den Landschaftszustand und die Landschaftsentwicklung im Uvs-Nuur-Becken (NW-Mongolei)},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-0001184},
  school      = {Universit{\"a}t Potsdam},
  year      = {2003},
  abstract  = {Im Landschaftszustand und in der Landschaftsentwicklung kommen funktionale Beziehungen zwischen dem naturbedingten Energie-, Wasser- und Stoffhaushalt einerseits und den Auswirkungen der Landnutzung andererseits zum Ausdruck. Gegenw{\"a}rtig ver{\"a}ndert der globale Anstieg der bodennahen Temperaturen vielerorts den landschaftlichen Energie-, Wasser- und Stoffhaushalt, wobei besonders in Trockengebieten zu erwarten ist, dass dieser Trend in Verbindung mit einer unangepassten Landnutzung das Regenerationsverm{\"o}gen der Vegetation einschr{\"a}nkt und zur Zerst{\"o}rung der Bodendecke f{\"u}hrt. F{\"u}r die Mongolei und f{\"u}r benachbarte Gebiete Asiens sind in Szenarien zur globalen Erw{\"a}rmung hohe Werte des Temperaturanstiegs prognostiziert worden. Eine globale Einsch{\"a}tzung der anthropogen induzierten Bodendegradation hat diese Region als stark oder extrem stark betroffen eingestuft. Vor diesem Hintergrund wurde im Uvs-Nuur-Becken, das im Nordwesten der Mongolei und damit in einer der trockensten Regionen des Landes gelegen ist, untersucht, wie sich der globale Temperaturanstieg auf der lokalen und regionalen Ebene widerspiegelt und wie der Landschaftshaushalt dabei ver{\"a}ndert wird. Die Auswirkungen des sommerlichen Witterungsverlaufes auf den Landschaftszustand sind 1997 bis 1999 an einem Transsekt erfasst worden, das sich zwischen dem Kharkhiraa-Gebirge am Westrand des Beckens und dem See Uvs Nuur im Beckeninneren von den Polsterfluren und Matten der alpinen Stufe {\"u}ber die Gebirgswaldsteppe, die Trockensteppe bis zur Halbw{\"u}ste erstreckt. An neun Messpunkten wurden witterungsklimatische Daten in Verbindung mit Merkmalen der Vegetation, des Bodens und der Bodenfeuchte aufgenommen. Die im Sommer 1998 gewonnenen Messwerte wurden mit Hilfe einer Clusteranalyse geb{\"u}ndelt und verdichtet. Auf dieser Grundlage konnten landschaftliche Zustandsformen inhaltlich gekennzeichnet, zeitlich eingeordnet und durch Zeit-Verhaltens-Modelle (Stacks) abgebildet werden. Aus den Zeit-Verhaltens-Modellen wird ersichtlich, dass man Zustandsformen, in denen die Hitze und die Trockenheit des Sommers 1998 besonders stark zum Ausdruck kommen, an allen Messpunkten beobachten kann, nimmt man die Station auf dem fast 3.000 m hohen Gipfel des Khukh Uul sowie die grundwasserbeeinflusste Station in unmittelbarer Seen{\"a}he aus. In ihrer extremen Form sind Trockenperioden jedoch nur im Beckeninneren und am Fuß der Randgebirge, also in der Halbw{\"u}ste, in der Trockensteppe und in der Wiesensteppe aufgetreten. Im Bergwald sowie im Bereich der alpinen Matten und Polsterfluren fehlen sie. Am st{\"a}rksten sind die grundwasserfreien Bereiche der Halbw{\"u}ste von der Hitze und Niederschlagsarmut des Sommers 1998 betroffen. An vier F{\"u}nfteln der Tage des Beobachtungszeitraumes herrscht an diesem Messpunkt extreme Trockenheit. Es f{\"a}llt entweder gar kein Niederschlag oder nur so wenig, dass der seit dem Fr{\"u}hjahr ersch{\"o}pfte Bodenwasservorrat nicht aufgef{\"u}llt wird. Das Verh{\"a}ltnis zwischen Niederschlag und potenzieller Verdunstung liegt hier bei 1:12. In der Halbw{\"u}ste zeichnet sich eine fortschreitende Desertifikation ab, zumal hier eine nichtangepasste Weidenutzung dominiert, in der Ziegen eine immer gr{\"o}ßere Rolle spielen. Dies gilt insbesondere f{\"u}r Bereiche in Siedlungsn{\"a}he. {\"O}rtlich ist auch der Bestand der Trockensteppe gef{\"a}hrdet, die sich an die Halbw{\"u}ste zum Beckenrand hin anschließt. Hier ist nicht nur die Viehdichte am h{\"o}chsten, sondern hier werden auch die meisten unbefestigten Fahrwege wild angelegt und die Bodendecke damit zerst{\"o}rt. Dies kann im Endeffekt zu einem {\"U}bergreifen von Prozessen der Desertifikation f{\"u}hren. Aus methodischer Sicht zeigt sich, dass die Kennzeichnung landschaftlicher Zustandsformen durch Zeit-Verhaltens-Modelle die Ermittlung der Auswirkungen von Witterung und Klima auf den Landschaftszustand erleichtert, da sie deren Aussage konzentriert. Zur Interpretation der Ergebnisse ist jedoch ein R{\"u}ckgriff auf die beschreibende Darstellung der Messwerte notwendig. Die im westlichen Uvs-Nuur-Becken und seinen Randgebirgen angewandte Verfahrensweise erm{\"o}glicht es, globale Aussagen zur globalen Erw{\"a}rmung der Kontinente regional oder lokal zu {\"u}berpr{\"u}fen und zu untersetzen."},
  language  = {de}
}
@phdthesis{Bookhagen2004,
  author    = {Bookhagen, Bodo},
  title     = {Late quaternary climate changes and landscape evolution in the Northwest Himalaya : geomorphologic processes in the Indian Summer Monsoon Domain},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-0001956},
  school      = {Universit{\"a}t Potsdam},
  year      = {2004},
  abstract  = {The India-Eurasia continental collision zone provides a spectacular example of active mountain building and climatic forcing. In order to quantify the critically important process of mass removal, I analyzed spatial and temporal precipitation patterns of the oscillating monsoon system and their geomorphic imprints. I processed passive microwave satellite data to derive high-resolution rainfall estimates for the last decade and identified an abnormal monsoon year in 2002. During this year, precipitation migrated far into the Sutlej Valley in the northwestern part of the Himalaya and reached regions behind orographic barriers that are normally arid. There, sediment flux, mean basin denudation rates, and channel-forming processes such as erosion by debris-flows increased significantly. Similarly, during the late Pleistocene and early Holocene, solar forcing increased the strength of the Indian summer monsoon for several millennia and presumably lead to analogous precipitation distribution as were observed during 2002. However, the persistent humid conditions in the steep, high-elevation parts of the Sutlej River resulted in deep-seated landsliding. Landslides were exceptionally large, mainly due to two processes that I infer for this time: At the onset of the intensified monsoon at 9.7 ka BP heavy rainfall and high river discharge removed material stored along the river, and lowered the baselevel. Second, enhanced discharge, sediment flux, and increased pore-water pressures along the hillslopes eventually lead to exceptionally large landslides that have not been observed in other periods. The excess sediments that were removed from the upstream parts of the Sutlej Valley were rapidly deposited in the low-gradient sectors of the lower Sutlej River. Timing of downcutting correlates with centennial-long weaker monsoon periods that were characterized by lower rainfall. I explain this relationship by taking sediment flux and rainfall dynamics into account: High sediment flux derived from the upstream parts of the Sutlej River during strong monsoon phases prevents fluvial incision due to oversaturation the fluvial sediment-transport capacity. In contrast, weaker monsoons result in a lower sediment flux that allows incision in the low-elevation parts of the Sutlej River.},
  language  = {en}
}
@phdthesis{Dahlke2020,
  author    = {Dahlke, Sandro},
  title     = {Rapid climate changes in the arctic region of Svalbard},
  doi       = {10.25932/publishup-44554},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-445542},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xv, 123},
  year      = {2020},
  abstract  = {Over the last decades, the Arctic regions of the earth have warmed at a rate 2-3 times faster than the global average- a phenomenon called Arctic Amplification. A complex, non-linear interplay of physical processes and unique pecularities in the Arctic climate system is responsible for this, but the relative role of individual processes remains to be debated. This thesis focuses on the climate change and related processes on Svalbard, an archipelago in the North Atlantic sector of the Arctic, which is shown to be a "hotspot" for the amplified recent warming during winter. In this highly dynamical region, both oceanic and atmospheric large-scale transports of heat and moisture interfere with spatially inhomogenous surface conditions, and the corresponding energy exchange strongly shapes the atmospheric boundary layer. In the first part, Pan-Svalbard gradients in the surface air temperature (SAT) and sea ice extent (SIE) in the fjords are quantified and characterized. This analysis is based on observational data from meteorological stations, operational sea ice charts, and hydrographic observations from the adjacent ocean, which cover the 1980-2016 period. It is revealed that typical estimates of SIE during late winter range from 40-50\% (80-90\%) in the western (eastern) parts of Svalbard. However, strong SAT warming during winter of the order of 2-3K per decade dictates excessive ice loss, leaving fjords in the western parts essentially ice-free in recent winters. It is further demostrated that warm water currents on the west coast of Svalbard, as well as meridional winds contribute to regional differences in the SIE evolution. In particular, the proximity to warm water masses of the West Spitsbergen Current can explain 20-37\% of SIE variability in fjords on west Svalbard, while meridional winds and associated ice drift may regionally explain 20-50\% of SIE variability in the north and northeast. Strong SAT warming has overruled these impacts in recent years, though. In the next part of the analysis, the contribution of large-scale atmospheric circulation changes to the Svalbard temperature development over the last 20 years is investigated. A study employing kinematic air-back trajectories for Ny-{\AA}lesund reveals a shift in the source regions of lower-troposheric air over time for both the winter and the summer season. In winter, air in the recent decade is more often of lower-latitude Atlantic origin, and less frequent of Arctic origin. This affects heat- and moisture advection towards Svalbard, potentially manipulating clouds and longwave downward radiation in that region. A closer investigation indicates that this shift during winter is associated with a strengthened Ural blocking high and Icelandic low, and contributes about 25\% to the observed winter warming on Svalbard over the last 20 years. Conversely, circulation changes during summer include a strengthened Greenland blocking high which leads to more frequent cold air advection from the central Arctic towards Svalbard, and less frequent air mass origins in the lower latitudes of the North Atlantic. Hence, circulation changes during winter are shown to have an amplifying effect on the recent warming on Svalbard, while summer circulation changes tend to mask warming. An observational case study using upper air soundings from the AWIPEV research station in Ny-{\AA}lesund during May-June 2017 underlines that such circulation changes during summer are associated with tropospheric anomalies in temperature, humidity and boundary layer height. In the last part of the analysis, the regional representativeness of the above described changes around Svalbard for the broader Arctic is investigated. Therefore, the terms in the diagnostic temperature equation in the Arctic-wide lower troposphere are examined for the Era-Interim atmospheric reanalysis product. Significant positive trends in diabatic heating rates, consistent with latent heat transfer to the atmosphere over regions of increasing ice melt, are found for all seasons over the Barents/Kara Seas, and in individual months in the vicinity of Svalbard. The above introduced warm (cold) advection trends during winter (summer) on Svalbard are successfully reproduced. Regarding winter, they are regionally confined to the Barents Sea and Fram Strait, between 70°-80°N, resembling a unique feature in the whole Arctic. Summer cold advection trends are confined to the area between eastern Greenland and Franz Josef Land, enclosing Svalbard.},
  language  = {en}
}
@phdthesis{Demory2004,
  author    = {Demory, Fran{\c{c}}ois},
  title     = {Paleomagnetic dating of climatic events in Late Quaternary sediments of Lake Baikal (Siberia)},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-0001720},
  school      = {Universit{\"a}t Potsdam},
  year      = {2004},
  abstract  = {Der Baikalsee ist ein ideales Klimaarchiv f{\"u}r die Mitte Eurasiens. In dieser Arbeit wurde gesteinsmagnetische und paleomagnetische Analysen an hemipelagischen Sequenzen von vier Lokationen analysiert. Die Kerne erreichen ein Alter von maximal 300 ky. In Kombination mit TEM, XRD, XRF und geochemischen Analysen zeigt die gesteinsmagnetische Studie, dass detritischer Magnetit das magnetische Signal der glazialen Sedimente dominiert. Die magnetischen Signale der interglazialen Sedimente wurden durch diagenetische Prozesse ver{\"a}ndert. Mittels HIRM k{\"o}nnen H{\"a}matit und Goethit quantifiziert werden. Diese Methode eignet sich, den detritischen Eintrag in den Baikalsee abzusch{\"a}tzen. Relative Paleointensit{\"a}ten des Erdmagnetfeldes ergaben reproduizerbare Muster, welche in Korrelation mit gutdatierten Referenzproben die Ableitung eines alternativen Altersmodells f{\"u}r die Datierung der Baikalsedimente erm{\"o}glichten. Bei Anwendung des paleomagnetischen Altersmodells beobachtet man, dass die Abk{\"u}hlung im Baikalgebiet und im Oberfl{\"a}chenwasser des Nordatlantiks wie sie aus den \&\#948;18 O-Werten planktonischer Foraminiferen abgeleitet werden kann, zeitgleich ist. Wird das aus benthischen \&\#948;18 O-Werten abgeleitete Altermdodell auf den Baikalsee angewandt, ergibt sich eine deutliche Zeitverschiebung. Das benthische Altersmodell repr{\"a}sentiert die globale Ver{\"a}nderung des Eisvolumens, welche sp{\"a}ter als die V{\"a}nderung der Oberfl{\"a}chenwassertemperatur auftritt. Die Kompilation paleomagnetischer Kurven ergab eine neue relative Paleointensit{\"a}tskurve \“Baikal 200\”. Mittels Korngr{\"o}ssenanalyse des Detritus konnten drei Faziestypen mit unterschiedlicher Sedimentationsdynamik unterschieden werden: 1) Glaziale Peroiden werden durch hohe Tongehalte infolge von Windeintrag und durch grobe Sandfraktion mittels Transport durch lokale Winde {\"u}ber das Eis charakterisiert. Dieser Faziestyp deutet auf arides Klima. 2) W{\"a}hrend der Glazial/Interglazial-{\"U}berg{\"a}nge steigt die Siltfraktion an. Dies deutet auf erh{\"o}hte Feuchtigkeit und damit verbunden erh{\"o}hte Sedimentdynamik. Windtransport und in den Schnee der Eisdecke eingetragener Staub sind die vorherrschenden Prozesse, welche den Silt in hemipelagischer Position zur Ablagerung bringen. 3) W{\"a}hrend des klimatischen Optimum des Eeemian werden Gr{\"o}sse und Quantit{\"a}t des Silts minimal, was auf eine geschlossene Vegetationsdecke im Hinterland deutet.},
  language  = {en}
}
@phdthesis{Folkertsma2020,
  author    = {Folkertsma, Remco},
  title     = {Evolutionary adaptation to climate in microtine mammals},
  doi       = {10.25932/publishup-47680},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-476807},
  school      = {Universit{\"a}t Potsdam},
  pages     = {135},
  year      = {2020},
  abstract  = {Understanding how organisms adapt to their local environment is a major focus of evolutionary biology. Local adaptation occurs when the forces of divergent natural selection are strong enough compared to the action of other evolutionary forces. An improved understanding of the genetic basis of local adaptation can inform about the evolutionary processes in populations and is of major importance because of its relevance to altered selection pressures due to climate change. So far, most insights have been gained by studying model organisms, but our understanding about the genetic basis of local adaptation in wild populations of species with little genomic resources is still limited. With the work presented in this thesis I therefore set out to provide insights into the genetic basis of local adaptation in populations of two voles species: the common vole (Microtus arvalis) and the bank vole (Myodes glareolus). Both voles species are small mammals, they have a high evolutionary potential compared to their dispersal capabilities and are thus likely to show genetic responses to local conditions, moreover, they have a wide distribution in which they experience a broad range of different environmental conditions, this makes them an ideal species to study local adaptation. The first study focused on producing a novel mitochondrial genome to facilitate further research in M. arvalis. To this end, I generated the first mitochondrial genome of M. arvalis using shotgun sequencing and an iterative mapping approach. This was subsequently used in a phylogenetic analysis that produced novel insights into the phylogenetic relationships of the Arvicolinae. The following two studies then focused on the genetic basis of local adaptation using ddRAD-sequencing data and genome scan methods. The first of these involved sequencing the genomic DNA of individuals from three low-altitude and three high-altitude M. arvalis study sites in the Swiss Alps. High-altitude environments with their low temperatures and low levels of oxygen (hypoxia) pose considerable challenges for small mammals. With their small body size and proportional large body surface they have to sustain high rates of aerobic metabolism to support thermogenesis and locomotion, which can be restricted with only limited levels of oxygen available. To generate insights into high-altitude adaptation I identified a large number of single nucleotide polymorphisms (SNPs). These data were first used to identify high levels of differentiation between study sites and a clear pattern of population structure, in line with a signal of isolation by distance. Using genome scan methods, I then identified signals of selection associated with differences in altitude in genes with functions related to oxygen transport into tissue and genes related to aerobic metabolic pathways. This indicates that hypoxia is an important selection pressure driving local adaptation at high altitude in M. arvalis. A number of these genes were linked with high-altitude adaptation in other species before, which lead to the suggestion that high-altitude populations of several species have evolved in a similar manner as a response to the unique conditions at high altitude The next study also involved the genetic basis of local adaptation, here I provided insights into climate-related adaptation in M. glareolus across its European distribution. Climate is an important environmental factor affecting the physiology of all organisms. In this study I identified a large number of SNPs in individuals from twelve M. glareolus populations distributed across Europe. I used these, to first establish that populations are highly differentiated and found a strong pattern of population structure with signal of isolation by distance. I then employed genome scan methods to identify candidate loci showing signals of selection associated with climate, with a particular emphasis on polygenic loci. A multivariate analysis was used to determine that temperature was the most important climate variable responsible for adaptive genetic variation among all variables tested. By using novel methods and genome annotation of related species I identified the function of genes of candidate loci. This showed that genes under selection have functions related to energy homeostasis and immune processes. Suggesting that M. glareolus populations have evolved in response to local temperature and specific local pathogenic selection pressures. The studies presented in this thesis provide evidence for the genetic basis of local adaptation in two vole species across different environmental gradients, suggesting that the identified genes are involved in local adaptation. This demonstrates that with the help of novel methods the study of wild populations, which often have little genomic resources available, can provide unique insights into evolutionary processes.},
  language  = {en}
}
@article{Fuhr2012,
  author    = {Fuhr, Harald},
  title     = {Klimawandel und Entwicklungspolitik},
  series = {Klimapolitik International},
  journal   = {Klimapolitik International},
  editor    = {Kleinw{\"a}chter, Kai},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1868-6222},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81301},
  pages     = {31 -- 40},
  year      = {2012},
  abstract  = {Der Autor diskutiert die Chancen und Risiken bei der Einbindung des S{\"u}dens in die internationale Klimapolitik. Lange Zeit hatten die Entwicklungsl{\"a}nder am wenigsten zum Klimawandel beigetragen, w{\"a}ren aber am st{\"a}rksten von ihm betroffen. Mittlerweile jedoch tragen diese L{\"a}nder in erheblichem Maße selbst zum Klimawandel bei. Allerdings setzen deren Regierungen auf Zeit. Sie erwarten Ressourcentransfers. Dies verst{\"a}rkt auch alte Probleme des ‚Rent-Seeking'.},
  language  = {de}
}
@phdthesis{Glushak2007,
  author    = {Glushak, Ksenia},
  title     = {Atmospheric circulation and the surface mass balance in a regional climate model of Antarctica},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17296},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {Understanding the Earth's climate system and particularly climate variability presents one of the most difficult and urgent challenges in science. The Antarctic plays a crucial role in the global climate system, since it is the principal region of radiative energy deficit and atmospheric cooling. An assessment of regional climate model HIRHAM is presented. The simulations are generated with the HIRHAM model, which is modified for Antarctic applications. With a horizontal resolution of 55km, the model has been run for the period 1958-1998 creating long-term simulations from initial and boundary conditions provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA40 re-analysis. The model output is compared with observations from observation stations, upper air data, global atmospheric analyses and satellite data. In comparison with the observations, the evaluation shows that the simulations with the HIRHAM model capture both the large and regional scale circulation features with generally small bias in the modeled variables. On the annual time scale the largest errors in the model simulations are the overestimation total cloud cover and the colder near-surface temperature over the interior of the Antarctic plateau. The low-level temperature inversion as well as low-level wind jet is well captured by the model. The decadal scale processes were studied based on trend calculations. The long-term run was divided into two 20 years parts. The 2m temperature, 500 hPa temperature, MSLP, precipitation and net mass balance trends were calculated for both periods and over 1958 - 1998. During the last two decades the strong surface cooling was observed over the Eastern Antarctica, this result is in good agreement with the result of Chapman and Walsh (2005) who calculated the temperature trend based on the observational data. The MSLP trend reveals a big disparity between the first and second parts of the 40 year run. The overall trend shows the strengthening of the circumpolar vortex and continental anticyclone. The net mass balance as well as precipitation show a positive trend over the Antarctic Peninsula region, along Wilkes Land and in Dronning Maud Land. The Antarctic ice sheet grows over the Eastern part of Antarctica with small exceptions in Dronning Maud Land and Wilkes Land and sinks in the Antarctic Peninsula; this result is in good agreement with the satellite-measured altitude presented in Davis (2005) . To better understand the horizontal structure of MSLP, temperature and net mass balance trends the influence of the Southern Annual Mode (SAM) on the Antarctic climate was investigated. The main meteorological parameters during the positive and negative Antarctic Oscillation (AAO) phases were compared to each other. A positive/negative AAO index means strengthening/weakening of the circumpolar vortex, poleward/northward storm tracks and prevailing/weakening westerly winds. For detailed investigation of global teleconnection, two positive and one negative periods of AAO phase were chosen. The differences in MSLP and 2m temperature between positive and negative AAO years during the winter months partly explain the surface cooling during the last decades.},
  language  = {en}
}
@phdthesis{Hanschmann2019,
  author    = {Hanschmann, Raffael Tino},
  title     = {Stalling the engine? EU climate politics after the 'Great Recession'},
  doi       = {10.25932/publishup-44044},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-440441},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XXVIII, 303},
  year      = {2019},
  abstract  = {This dissertation investigates the impact of the economic and fiscal crisis starting in 2008 on EU climate policy-making. While the overall number of adopted greenhouse gas emission reduction policies declined in the crisis aftermath, EU lawmakers decided to introduce new or tighten existing regulations in some important policy domains. Existing knowledge about the crisis impact on EU legislative decision-making cannot explain these inconsistencies. In response, this study develops an actor-centred conceptual framework based on rational choice institutionalism that provides a micro-level link to explain how economic crises translate into altered policy-making patterns. The core theoretical argument draws on redistributive conflicts, arguing that tensions between 'beneficiaries' and 'losers' of a regulatory initiative intensify during economic crises and spill over to the policy domain. To test this hypothesis and using social network analysis, this study analyses policy processes in three case studies: The introduction of carbon dioxide emission limits for passenger cars, the expansion of the EU Emissions Trading System to aviation, and the introduction of a regulatory framework for biofuels. The key finding is that an economic shock causes EU policy domains to polarise politically, resulting in intensified conflict and more difficult decision-making. The results also show that this process of political polarisation roots in the industry that is the subject of the regulation, and that intergovernmental bargaining among member states becomes more important, but also more difficult in times of crisis.},
  language  = {en}
}
@article{HarnischWienges2012,
  author    = {Harnisch, Astrid and Wienges, Sebastian},
  title     = {Wie Klimaschutz finanzieren?},
  series = {Klimapolitik International},
  journal   = {Klimapolitik International},
  editor    = {Kleinw{\"a}chter, Kai},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1868-6222},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81328},
  pages     = {50 -- 58},
  year      = {2012},
  abstract  = {Zur Finanzierung von Klimaschutz m{\"u}ssen {\"o}ffentliche Mittel gezielt eingesetzt werden. Dies beinhaltet auch die Rahmenbedingungen f{\"u}r private Finanzstr{\"o}me signifikant zu verbessern. Anhand einer Problemanalyse bestimmen die Autoren Eckdaten f{\"u}r diese Hebelwirkung. {\"O}ffentliche Anschubfinanzierung kann somit die Grundlage f{\"u}r private Investitionen sein. Dies wird exemplarisch an der Internationalen Klimaschutzinitiative des Bundesumweltministeriums diskutiert.},
  language  = {de}
}