@article{TaftWiechertZhangetal.2013,
  author    = {Taft, Linda and Wiechert, Uwe and Zhang, Hucai and Lei, Guoliang and Mischke, Steffen and Plessen, Birgit and Weynell, Marc and Winkler, Andreas and Riedel, Frank},
  title     = {Oxygen and carbon isotope patterns archived in shells of the aquatic gastropod Radix - hydrologic and climatic signals across the Tibetan Plateau in sub-monthly resolution},
  series = {Quaternary international : the journal of the International Union for Quaternary Research},
  volume    = {290},
  journal   = {Quaternary international : the journal of the International Union for Quaternary Research},
  number    = {1},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {1040-6182},
  doi       = {10.1016/j.quaint.2012.10.031},
  pages     = {282 -- 298},
  year      = {2013},
  abstract  = {The Tibetan Plateau (TP), including its surrounding mountain ranges, represents the largest store of ice outside the polar regions. It hosts numerous lakes as well as the head waters of major Asian rivers, on which billions of people depend, and it is particularly sensitive to climate change. The moisture transport to the TP is controlled by the Indian and Pacific monsoon and the Westerlies. Understanding the evolution of the interaction of these circulation systems requires studies on climate archives in different spatial and temporal contexts. The objective of this study is to learn more about the interannual variability of precipitation patterns across the TP and how different hydrologic systems react to different climatic factors. Aragonite shells of the aquatic gastropod Radix, which is widely distributed in the region, may represent suitable archives for inferring hydrologic and climatic signals in particularly high resolution. Therefore, sclerochronological studies of delta O-18 and delta C-13 ratios in Radix shells from seven lakes were conducted, each representing a different hydrologic and climatic setting, on a transect from the Pamirs across the TP. The shell patterns exhibit an increasing influence of precipitation and a decreasing influence of evaporation on the isotope compositions from west to east. delta O-18 values of shells from lakes on the eastern and central TP (Donggi Cona, Yamdrok Yumco, Tarab Co) mirror monsoon signals, indicated by more negative values and higher variabilities compared to the more western lakes (Karakul, Bangong/Nyak, Manasarovar). In Yadang Co, located on the central southern TP, the monsoon rains did not reach the lake in the sampling year, although it is located in a region which is usually affected by monsoon circulation. The delta O-18 values are used to differentiate the annual hydrological cycle into ice cover period, melt water period, precipitation period and evaporation period. delta C-13 compositions in the shells particularly depend on specific habitats, which vary in biological productivity and in carbon sources. delta O-18 and delta C-13 patterns show a positive covariance in shells originating from large closed basins. The results show that Radix shells mirror general climatic differences between the seven lake regions. These differences reflect both regional and local climate signals in sub-seasonal resolution, without noticeable dependence on the particular lake system.},
  language  = {en}
}
@article{TaftMischkeWiechertetal.2014,
  author    = {Taft, Linda and Mischke, Steffen and Wiechert, Uwe and Leipe, Christian and Rajabov, Ilhomjon and Riedel, Frank},
  title     = {Sclerochronological oxygen and carbon isotope ratios in Radix (Gastropoda) shells indicate changes of glacial meltwater flux and temperature since 4,200 cal yr BP at Lake Karakul, eastern Pamirs (Tajikistan)},
  series = {Journal of paleolimnolog},
  volume    = {52},
  journal   = {Journal of paleolimnolog},
  number    = {1-2},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {0921-2728},
  doi       = {10.1007/s10933-014-9776-4},
  pages     = {27 -- 41},
  year      = {2014},
  abstract  = {We report delta O-18 and delta C-13 values of 21 fossil shells from the aquatic gastropod Radix from a sediment core taken in the eastern basin of Lake Karakul, Tajikistan (38.86-39.16A degrees N, 73.26-73.56A degrees E, 3,928 m above sea level) and covering the last 4,200 cal yr BP. The lake is surrounded by many palaeoshorelines evidencing former lake-level changes, most likely triggered by changes in meltwater flux. This hypothesis was tested by interpreting the isotope ratios of Radix shells together with delta O-18 values of Ostracoda and of authigenic aragonite. The mean delta O-18 values of Radix and Ostracoda fall along the same long-term trend indicating a change in the isotopic composition of precipitation, which contributed to the glaciers in the catchment as snow and finally as melt water to the lake. The sclerochronological delta O-18 and delta C-13 patterns in Radix shells provide seasonal weather information, which is discussed in context with previously proposed climatic changes during the last 4,200 cal yr BP. The period between similar to 4,200 and 3,000 cal yr BP was characterized by stepwise glacier advance in the catchment most likely due to a precipitation surplus. Subsequently the climate remained relatively cold but the lake level fluctuated, as indicated by ostracod shell isotope data. From similar to 1,800 cal yr BP the sclerochronological patterns provide evidence for increasing melt water flux and transport of allochthonous carbon into the lake, most likely due to an accelerated glacier retreat. The period around 1,500 cal yr BP was characterized by strong warming, increasing meltwater flux, glacier retreat and an increasing lake level. Warm conditions continued until similar to 500 cal yr I'P probably representing the end of the Medieval Warm Period. A short relatively cold (dry?) period and a lower lake level are assumed for similar to 350 cal yr BP, possibly an analogue to the Maunder Minimum cooling in the North Atlantic region. Our results show that the lake system is complex, and that changes were triggered by external forcing and feedbacks. The similarity of delta O-18 values in Radix and ostracod shells demonstrates that both archives provide complementary information.},
  language  = {en}
}
@misc{PaulyHelleMiramontetal.2018,
  author    = {Pauly, Maren and Helle, Gerhard and Miramont, C{\´e}cile and B{\"u}ntgen, Ulf and Treydte, Kerstin and Reinig, Frederick and Guibal, Fr{\´e}d{\´e}ric and Sivan, Olivier and Heinrich, Ingo and Riedel, Frank and Kromer, Bernd and Balanzategui, Daniel and Wacker, Lukas and Sookdeo, Adam Sookdeo and Brauer, Achim},
  title     = {Subfossil trees suggest enhanced Mediterranean hydroclimate variability at the onset of the Younger Dryas},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1135},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-45916},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-459169},
  pages     = {10},
  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{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}
}