Stratification of very deep, thermally stratified lakes
Stratification of very deep, thermally stratified lakes
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DOI：
10.1029/2008gl034519
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发表时间：
2008-08-30
影响因子：
5.2
通讯作者：
Chikita, Kazuhisa
中科院分区：
文献类型：
--
作者：
Boehrer, Bertram;Fukuyama, Ryuji;Chikita, Kazuhisa
在非常深的淡水湖中，深层再循环与较浅的湖泊表现出显著的差异。我们考虑密度梯度完全由温差引起的分层。讨论了不同气候条件下的年环流型。在秋季和春季的T-md过渡期间，非常深的湖泊不一定会完全倾覆。在年循环过程中，地表温度超过4℃的情况下，得到了分层的特点：第一，秋季和春季环流不对称，第二，温度接近Tmd剖面，第三，等温深水。我们比较了水平均质湖的概念模型结果与日本非常深的火山口湖（池田湖、太泽湖、托谷湖、库塔拉湖和四津湖）的测量结果。在少聚湖泊和热压分层湖泊之间，我们发现湖泊尽管深度巨大，但循环可靠。通过与20世纪20年代和30年代的单点测量结果的比较，我们讨论了对气候变率的敏感性。
In very deep freshwater lakes, deep recirculation presents itself with remarkable differences to shallower lakes. We consider the stratification where density gradients are exclusively due to temperature differences. The annual circulation patterns are discussed for various climatic conditions. Very deep lakes do not necessarily produce full overturns during T-md transition in autumn and spring. Peculiarities of the stratification are derived for cases, in which surface temperatures cross 4 degrees C during the annual cycle: Firstly, the asymmetry between autumn and spring circulation, secondly, the proximity of temperature to the Tmd profile, and thirdly, the isothermal deep water. We compare conceptual model results of horizontally homogeneous lakes with measurements in very deep caldera lakes in Japan (Lakes Ikeda, Tazawa, Toya, Kuttara and Shikotsu). Between oligomictic lakes and thermobarically stratified lakes, we have found lakes circulating reliably despite their enormous depth. We discuss susceptibility to climate variability supported by comparisons with single point measurements from the 1920s and 1930s.