DOI: 10.1016/j.quascirev.2015.03.002
Scopus记录号: 2-s2.0-84961289194
论文题名: A millennial-long record of warm season precipitation and flood frequency for the North-western Alps inferred from varved lake sediments: Implications for the future
作者: Amann B. ; Szidat S. ; Grosjean M.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 115 起始页码: 89
结束页码: 100
语种: 英语
英文关键词: Climate change
; Paleoclimatology
; Paleofloods
; Proglacial lake
; Sedimentology
; Varve chronology
Scopus关键词: Catchments
; Climate change
; Climate models
; Cooling systems
; Driers (materials)
; Lakes
; Sedimentology
; Sediments
; Water resources
; Centennial variability
; Paleoclimatology
; Paleofloods
; Positive correlations
; Proglacial lakes
; Regional climate models
; Varve chronologies
; Warm season precipitation
; Floods
; climate modeling
; climate variation
; flood frequency
; future prospect
; geochronology
; global climate
; global warming
; Holocene
; lacustrine deposit
; lamination
; paleoclimate
; paleoflood
; periodicity
; precipitation (climatology)
; proglacial environment
; sedimentology
; varve
; Alps
; Switzerland
英文摘要: The recent warming of the global climate is well recognized. However, does a warmer climate also mean a moister climate? Does dry get drier and wet get wetter? There are important questions as they relate to changes in the water cycle and impacts the water resources as well as the frequency and intensity of storms and floods in the near future. In Europe, regional climate models do not show consistent and robust results for future hydroclimatic changes and how extreme events will evolve in response to future climate change.Paleo-hydroclimatic data from natural archives are one of the few means to assess such changes in the longer context. Here, we present an annually-resolved record of warm season (MJJA) precipitation and summer flood frequency from the varved (annually laminated) sediments of proglacial Lake Oeschinen (46°30'N-7°44'E, 1580m, NW Swiss Alps) back to AD 884. These data sets are inferred from the thickness of annual sediment deposits and the occurrence of flood event layers in the sediments. The chronology of the sediment record is based on multiple varve counts and validated with historical floods chronicled in written documents (back to the 14th century) and 14C AMS dates.The precipitation record shows pronounced interannual to centennial variability with humid warm season phases between AD 920-950, AD 1100-1180, AD 1300-1400, AD 1590-1650, AD 1700-1790, AD 1820-1880, and AD 1960-2008. Driest conditions are reconstructed for AD 960-1080, AD 1250-1300 and for AD 1880-1900. Our precipitation record is consistent with the few multi-centennial warm-season precipitation records available for Europe.We did not find a persistent relationship between warm-season precipitation and temperature. In contrast, results show that the relation between precipitation and temperature has oscillated between positive correlations (warmer gets wetter, cooler gets drier) and negative correlations (warmer gets drier, cooler gets wetter) with a highly significant (χ2=99%) multidecadal (60-70yrs) periodicity over the last millennium. Possible explanations for this phenomenon are changes in the weather type statistics or the within-weather-type variability, which influence the combinations between precipitation and temperature over continental central Europe and operate at multidecadal scales. Such multidecadal effects might also be important for precipitation scenarios in the Alpine area under future warming.Our record of flood frequency suggests more frequent floods under cool and humid climate during the warm seasons. This picture is consistent with other studies from small and medium size catchments at mid- and high elevations in the Alpine area. However, the 13th century reveals a period with high flood frequency during warm and moderately dry (average precipitation) conditions. This anomalous situation is currently not understood; nonetheless, this is also one out of several possible scenarios for the future. From the different combinations found in our record, we conclude that the relation between floods, precipitation and temperature and, in consequence, future projections remain poorly constrained. © 2015. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59952
Appears in Collections: 过去全球变化的重建
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作者单位: Oeschger Centre for Climate Change Research and Institute of Geography, University of Bern, Erlachstrasse 9a T3, Bern, Switzerland; Oeschger Centre for Climate Change Research and Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, Switzerland
Recommended Citation:
Amann B.,Szidat S.,Grosjean M.. A millennial-long record of warm season precipitation and flood frequency for the North-western Alps inferred from varved lake sediments: Implications for the future[J]. Quaternary Science Reviews,2015-01-01,115