@misc{ScheweLevermann2017,
  author    = {Schewe, Jacob and Levermann, Anders},
  title     = {Non-linear intensification of Sahel rainfall as a possible dynamic response to future warming},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  number    = {630},
  doi       = {10.25932/publishup-41911},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419114},
  pages     = {495 -- 505},
  year      = {2017},
  abstract  = {Projections of the response of Sahel rainfall to future global warming diverge significantly. Meanwhile, paleoclimatic records suggest that Sahel rainfall is capable of abrupt transitions in response to gradual forcing. Here we present climate modeling evidence for the possibility of an abrupt intensification of Sahel rainfall under future climate change. Analyzing 30 coupled global climate model simulations, we identify seven models where central Sahel rainfall increases by 40 to 300\% over the 21st century, owing to a northward expansion of the West African monsoon domain. Rainfall in these models is non-linearly related to sea surface temperature (SST) in the tropical Atlantic and Mediterranean moisture source regions, intensifying abruptly beyond a certain SST warming level. We argue that this behavior is consistent with a self-amplifying dynamic-thermodynamical feedback, implying that the gradual increase in oceanic moisture availability under warming could trigger a sudden intensification of monsoon rainfall far inland of today's core monsoon region.},
  language  = {en}
}
@misc{GoswamiBoersRheinwaltetal.2018,
  author    = {Goswami, Bedartha and Boers, Niklas and Rheinwalt, Aljoscha and Marwan, Norbert and Heitzig, Jobst and Breitenbach, Sebastian Franz Martin and Kurths, J{\"u}rgen},
  title     = {Abrupt transitions in time series with uncertainties},
  series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  number    = {576},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-42311},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423111},
  pages     = {10},
  year      = {2018},
  abstract  = {Identifying abrupt transitions is a key question in various disciplines. Existing transition detection methods, however, do not rigorously account for time series uncertainties, often neglecting them altogether or assuming them to be independent and qualitatively similar. Here, we introduce a novel approach suited to handle uncertainties by representing the time series as a time-ordered sequence of probability density functions. We show how to detect abrupt transitions in such a sequence using the community structure of networks representing probabilities of recurrence. Using our approach, we detect transitions in global stock indices related to well-known periods of politico-economic volatility. We further uncover transitions in the El Nino-Southern Oscillation which coincide with periods of phase locking with the Pacific Decadal Oscillation. Finally, we provide for the first time an 'uncertainty-aware' framework which validates the hypothesis that ice-rafting events in the North Atlantic during the Holocene were synchronous with a weakened Asian summer monsoon.},
  language  = {en}
}
@misc{CaoHerzschuhNietal.2014,
  author    = {Cao, Xianyong and Herzschuh, Ulrike and Ni, Jian and Zhao, Yan and B{\"o}hmer, Thomas},
  title     = {Spatial and temporal distributions of major tree taxa in eastern continental Asia during the last 22,000 years},
  series = {The Holocene},
  volume    = {25},
  journal   = {The Holocene},
  number    = {1},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-404176},
  pages     = {13},
  year      = {2014},
  abstract  = {This study investigates the spatial and temporal distributions of 14 key arboreal taxa and their driving forces during the last 22,000 calendar years before ad 1950 (kyr BP) using a taxonomically harmonized and temporally standardized fossil pollen dataset with a 500-year resolution from the eastern part of continental Asia. Logistic regression was used to estimate pollen abundance thresholds for vegetation occurrence (presence or dominance), based on modern pollen data and present ranges of 14 taxa in China. Our investigation reveals marked changes in spatial and temporal distributions of the major arboreal taxa. The thermophilous (Castanea, Castanopsis, Cyclobalanopsis, Fagus, Pterocarya) and eurythermal (Juglans, Quercus, Tilia, Ulmus) broadleaved tree taxa were restricted to the current tropical or subtropical areas of China during the Last Glacial Maximum (LGM) and spread northward since c. 14.5 kyr BP. Betula and conifer taxa (Abies, Picea, Pinus), in contrast, retained a wider distribution during the LGM and showed no distinct expansion direction during the Late Glacial. Since the late mid-Holocene, the abundance but not the spatial extent of most trees decreased. The changes in spatial and temporal distributions for the 14 taxa are a reflection of climate changes, in particular monsoonal moisture, and, in the late Holocene, human impact. The post-LGM expansion patterns in eastern continental China seem to be different from those reported for Europe and North America, for example, the westward spread for eurythermal broadleaved taxa.},
  language  = {en}
}
@misc{BattarbeeLambBennettetal.2015,
  author    = {Battarbee, Richard W. and Lamb, Henry F. and Bennett, Keith and Edwards, Mary and Bjune, Anne E. and Kaland, Peter E. and Berglund, Bj{\"o}rn E. and Lotter, Andr{\´e} F. and Sepp{\"a}, Heikki and Willis, Kathy J. and Herzschuh, Ulrike and Birks, Hilary H.},
  title     = {John Birks},
  series = {The Holocene},
  journal   = {The Holocene},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-404544},
  pages     = {14},
  year      = {2015},
  abstract  = {We describe the career of John Birks as a pioneering scientist who has, over a career spanning five decades, transformed palaeoecology from a largely descriptive to a rigorous quantitative science relevant to contemporary questions in ecology and environmental change. We review his influence on students and colleagues not only at Cambridge and Bergen Universities, his places of primary employment, but also on individuals and research groups in Europe and North America. We also introduce the collection of papers that we have assembled in his honour. The papers are written by his former students and close colleagues and span many of the areas of palaeoecology to which John himself has made major contributions. These include the relationship between ecology and palaeoecology, late-glacial and Holocene palaeoecology, ecological succession, climate change and vegetation history, the role of palaeoecological techniques in reconstructing and understanding the impact of human activity on terrestrial and freshwater ecosystems and numerical analysis of multivariate palaeoecological data.},
  language  = {en}
}