Generalized scaling of seasonal thermal stratification in lakes
Generalized scaling of seasonal thermal stratification in lakes
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DOI：
10.1016/j.earscirev.2016.08.008
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发表时间：
2016-10-01
影响因子：
12.1
通讯作者：
Shatwell, T.
中科院分区：
文献类型：
--
作者：
Kirillin, G.;Shatwell, T.
哈钦森和Loffler（1956）基于季节性热混合状态的湖泊分类已经成为任何将湖泊作为地球表面元素的分析的基石。然而，到目前为止，湖泊分类缺乏一个物理上合理的定量标准，区分两种基本的湖泊类型：一年中大部分时间的热分层（单混合和二混合）和主要混合到底部（多混合）。利用势能和动能之间的机械平衡，我们回顾了不同的Richardson数公式，推导出一个广义尺度的季节分层在封闭的湖盆。缩放参数是临界平均盆地深度，H-临界，划定湖泊，定期从那些分层的湖水透明度，湖泊长度，和莫宁-奥布霍夫长度的年度平均估计的基础上，季节性混合。我们使用逻辑回归验证全球湖泊的可用数据的缩放。缩放标准一贯描述的混合制度显着优于传统的无界盆地缩放或一个简单的深度阈值。因此，广义尺度是通用的淡水湖泊，并允许季节性混合制度估计没有数值求解热输运方程。(C)2016作者由Elsevier B. V.出版。这是一篇开放获取的文章，在CC BY许可证下
Hutchinson and Loffler's (1956) classification of lakes based on the seasonal thermal mixing regime has become a cornerstone of any analysis of lakes as elements of the earth surface. Until now however the lake classification has lacked a physically sound quantitative criterion distinguishing between two fundamental lake types: thermally stratified during a large portion of the year (mono- and dimictic) and predominantly mixed to the bottom (polymictic). Using the mechanistic balance between potential and kinetic energy we review the different formulations of the Richardson number to derive a generalized scaling for seasonal stratification in a dosed lake basin. The scaling parameter is the critical mean basin depth, H-crit, that delineates lakes that mix regularly from those that stratify seasonally based on lake water transparency, lake length, and an annual mean estimate for the Monin-Obukhov length. We validate the scaling on available data of lakes worldwide using logistic regression. The scaling criterion consistently described the mixing regime significantly better than either the conventional unbounded basin scaling or a simple depth threshold. Thus, the generalized scaling is universal for freshwater lakes and allows the seasonal mixing regime to be estimated without numerically solving the heat transport equations. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license