DOI: 10.1016/j.quascirev.2013.10.007
Scopus记录号: 2-s2.0-84886648105
论文题名: Cold-season temperatures in the European Alps during the past millennium: Variability, seasonality and recent trends
作者: De Jong R. ; Kamenik C. ; Grosjean M.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 82 起始页码: 1
结束页码: 12
语种: 英语
英文关键词: Anthropocene
; Climatic change
; Lake sediments
; Late Holocene
; Little ice age
; NAO
; Varves
Scopus关键词: Anthropocene
; Climatic changes
; Lake sediments
; Late Holocene
; Little Ice Age
; NAO
; Varves
; Atmospheric pressure
; Atmospheric temperature
; Greenhouse gases
; Lakes
; Meteorology
; Climate change
; accuracy assessment
; air temperature
; airflow
; chronology
; climate forcing
; climate variation
; Little Ice Age
; North Atlantic Oscillation
; parameterization
; quantitative analysis
; seasonal variation
; sediment analysis
; spatial analysis
; Alps
; Europe
英文摘要: This study presents a proxy-based, quantitative reconstruction of cold-season (mean October to May, TOct-May) air temperatures covering nearly the entire last millennium (AD 1060-2003, some hiatuses).The reconstruction was based on subfossil chrysophyte stomatocyst remains in the varved sediments of high-Alpine Lake Silvaplana, eastern Swiss Alps (46°27'N, 9°48'W, 1791m a.s.l.). Previous studies have demonstrated the reliability of this proxy by comparison to meteorological data. Cold-season air temperatures could therefore be reconstructed quantitatively, at a high resolution (5-yr) and with high chronological accuracy. Spatial correlation analysis suggests that the reconstruction reflects cold season climate variability over the high- Alpine region and substantial parts of central and western Europe.Cold-season temperatures were characterized by a relatively stable first part of the millennium until AD 1440 (2σ of 5-yr mean values=0.7°C) and highly variable TOct-May after that (AD 1440-1900, 2σ of 5-yr mean values=1.3°C). Recent decades (AD, 1991-present) were unusually warm in the context of the last millennium (exceeding the 2σ-range of the mean decadal TOct-May) but this warmth was not unprecedented. The coolest decades occurred from AD 1510-1520 and AD 1880-1890. The timing of extremely warm and cold decades is generally in good agreement with documentary data representing Switzerland and central European lowlands.The transition from relatively stable to highly variable TOct-May coincided with large changes in atmospheric circulation patterns in the North Atlantic region. Comparison of reconstructed cold season temperatures to the North Atlantic Oscillation index (NAO) during the past 1000 years showed that the relatively stable and warm conditions at the study site until AD 1440 coincided with a persistent positive mode of the NAO. We propose that the transition to large TOct-May variability around AD 1440 was linked to the subsequent absence of this persistent zonal flow pattern, which would allow other climatic drivers to gain importance in the study area. From AD 1440-1900, the similarity of reconstructed TOct-May to reconstructed air pressure in the Siberian High suggests a relatively strong influence of continental anticyclonic systems on Alpine cold season climate parameters during periods when westerly airflow was subdued. A more continental type of atmospheric circulation thus seems to be characteristic for the Little Ice Age in Europe.Comparison of Toct-May to summer temperature reconstructions from the same study site shows that, as expected, summer and cold season temperature trends and variability differed completely throughout nearly the entire last 1000 years. Since AD 1980, however, summer and cold season temperatures show a simultaneous, strong increase, which is unprecedented in the context of the last millennium. We suggest that the most likely explanation for this recent trend is anthropogenic greenhouse gas (GHG) forcing. © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60433
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, University of Bern, Zähringerstrasse 25, CH-3012 Bern, Switzerland; Institute of Geography, University of Bern, Erlachstrasse 9a, CH-3012 Bern, Switzerland
Recommended Citation:
De Jong R.,Kamenik C.,Grosjean M.. Cold-season temperatures in the European Alps during the past millennium: Variability, seasonality and recent trends[J]. Quaternary Science Reviews,2013-01-01,82