文章基本信息

标题：Diverging site-specific trends in the water temperature of a large boreal lake in winter and summer due to mixed effects of local features and climate change
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作者：Ari Voutilainen ; Timo Huttula ; Janne Juntunen 等
期刊名称：Boreal Environment Research
印刷版ISSN：1239-6095
出版年度：2014
卷号：19
期号：2
页码：104-114
语种：English
出版社：Finnish Limnological Society
摘要：We present diverging long-term trends in the water temperature of a large boreal lake, Lake Pyhäselkä (263 km2), located in eastern Finland. The dataset was constructed from a half century of monitoring (1962–2010). The direction of the temperature trend depended on the water layer and the season, in that the yearly average temperature in the top layer (1–10 m) as recorded in summer (June–August) increased by 2.5 °C over the monitoring period, whereas that recorded when the lake was covered by ice (January–April) decreased from 0.6 to 0.2 °C. The water temperature in the bottommost layers showed no trends. We suggest that the water temperature under the ice is decreasing in this case as a consequence of mixed effects of lake-specific physical features and climate change, which cause variations in the heat content of the inflowing water of the Pielisjoki. The epilimnetic water temperature in summer appeared in turn to follow general trends in air temperatures. Our results stress the need for taking local and site-specific phenomena into account when drawing conclusions about the effects of climate change on lakes.