DOI: 10.1016/j.palaeo.2013.03.016
论文题名: Hydroclimatic variations over the last millennium in eastern Finland disentangled by fossil Cladocera
作者: Nevalainen L. ; Helama S. ; Luoto T.P.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2013
卷: 378 起始页码: 13
结束页码: 21
语种: 英语
英文关键词: Effective moisture
; Lake sediments
; Little Ice Age
; Medieval Climate Anomaly
; Paleohydrology
; Scandinavia
英文摘要: Future climate warming is expected to alter atmospheric moisture balance and therefore paleoclimatic archives of past moisture and hydrological patterns may provide understanding of the magnitude, speed, and ecosystem responses to the regionally altered climatic regimes. The present study aimed at disentangling millennial variation in hydroclimatic parameters, including summer effective moisture (lake levels) and ice-free season by using sedimentary cladoceran fossils. We used a site-specific cladoceran-based inference model to reconstruct lake level fluctuations in a 1500-yr sediment record from Lake Pieni-Kauro, eastern Finland in the context of previously established paleoclimatic data of summer temperature and precipitation. In addition, we applied cladoceran planktonic/littoral ratio, mean body size, and abundance of fossil ephippia as supplementary proxies for paleoclimatic interpretations. The results showed that lake level was lower during the pre- and early Medieval Climate Anomaly (MCA, around 500-1000 AD) than at present and started to rise toward the culmination during the Little Ice Age (LIA, around 1600-1700. AD) when the lake level was higher than at present. Pelagic cladoceran body size was larger and abundance of ephippia increased during the LIA suggesting significant reduction in the length of the ice-free season and lower water temperatures. Comparison of the lake level reconstruction with the previous paleoclimatic data suggested that effective moisture has had a long-term negative relationship with temperature and positive relationship with summer precipitation in eastern Finland. The results indicated that the pre- and early MCA was warm and dry (long ice-free season, low summer effective moisture) and the culmination of the LIA was cool and moist (reduced ice-free season, increased summer effective moisture). Unraveling the seasonality of the multicentury hydroclimatic patterns in eastern Finland may offer important insights in linking the large-scale atmospheric circulation patterns to seasonal climate events. © 2013 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69745
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Environmental Sciences, University of Helsinki, Niemenkatu 73, FI-15140 Lahti, Finland; Finnish Forest Research Institute, P.O. Box 16 (Eteläranta 55), FI-96301 Rovaniemi, Finland; Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
Recommended Citation:
Nevalainen L.,Helama S.,Luoto T.P.. Hydroclimatic variations over the last millennium in eastern Finland disentangled by fossil Cladocera[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2013-01-01,378