DOI: 10.1016/j.quascirev.2013.09.002
Scopus记录号: 2-s2.0-84884914409
论文题名: Holocene flood frequency across the Central Alps - solar forcing and evidence for variations in North Atlantic atmospheric circulation
作者: Wirth S.B. ; Glur L. ; Gilli A. ; Anselmetti F.S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 80 起始页码: 112
结束页码: 128
语种: 英语
英文关键词: Alps
; Flood reconstruction
; Heavy precipitation
; Lake sediments
; NAO
; North Atlantic
; Solar forcing
Scopus关键词: Alps
; Heavy precipitation
; Lake sediments
; NAO
; North Atlantic
; Solar forcing
; Climate change
; Lakes
; Oceanography
; Sediments
; Solar energy
; Solar radiation
; Floods
; atmospheric circulation
; climate forcing
; flood frequency
; Holocene
; North Atlantic Oscillation
; solar activity
; Alps
; Atlantic Ocean
; Atlantic Ocean (North)
英文摘要: The frequency of large-scale heavy precipitation events in the European Alps is expected to undergo substantial changes with current climate change. Hence, knowledge about the past natural variability of floods caused by heavy precipitation constitutes important input for climate projections. We present a comprehensive Holocene (10,000 years) reconstruction of the flood frequency in the Central European Alps combining 15 lacustrine sediment records. These records provide an extensive catalogof flood deposits, which were generated by flood-induced underflows delivering terrestrial material to the lake floors. The multi-archive approach allows suppressing local weather patterns, such as thunderstorms, from the obtained climate signal. We reconstructed mainly late spring to fall events since ice cover and precipitation in form of snow in winter at high-altitude study sites do inhibit the generation of flood layers. We found that flood frequency was higher during cool periods, coinciding with lows in solar activity. In addition, flood occurrence shows periodicities that are also observed in reconstructions of solar activity from 14C and 10Be records (2500-3000, 900-1200, as well as of about 710, 500, 350, 208 (Suess cycle), 150, 104 and 87 (Gleissberg cycle) years). As atmospheric mechanism, we propose an expansion/shrinking of the Hadley cell with increasing/decreasing air temperature, causing dry/wet conditions in Central Europe during phases of high/low solar activity. Furthermore, differences between the flood patterns from the Northern Alps and the Southern Alps indicate changes in North Atlantic circulation. Enhanced flood occurrence in the South compared to the North suggests a pronounced southward position of the Westerlies and/or blocking over the northern North Atlantic, hence resembling a negative NAO state (most distinct from 4.2 to 2.4kyr BP and during the Little Ice Age). South-Alpine flood activity therefore provides a qualitative record of variations in a paleo-NAO pattern during the Holocene. Additionally, increased South Alpine flood activity contrasts to low precipitation in tropical Central America (Cariaco Basin) on the Holocene and centennial time scale. This observation is consistent with a Holocene southward migration of the Atlantic circulation system, and hence of the ITCZ, driven by decreasing summer insolation in the Northern hemisphere, as well as with shorter-term fluctuations probably driven by solar activity. © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60461
Appears in Collections: 过去全球变化的重建
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作者单位: Geological Institute, ETH Zurich, Zurich, Switzerland; Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; Institute of Geological Sciences and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
Recommended Citation:
Wirth S.B.,Glur L.,Gilli A.,et al. Holocene flood frequency across the Central Alps - solar forcing and evidence for variations in North Atlantic atmospheric circulation[J]. Quaternary Science Reviews,2013-01-01,80