Water-ice heat exchange and ice-water boundary layer in freshwater lakes

正在进行的项目侧重于确定季节性冰盖形成和融化的物理过程的量化。该项目是德国和俄罗斯的合作项目，结合了对欧洲北极湖泊和贝加尔湖的研究。在项目的初始阶段，对大规模实地活动结果的分析揭示了冰下水运动-地转流和短期假潮振荡-在加速冰基融化方面所起的关键作用。这些结果导致制定一个统一的假设缩放水冰热通量与耗散率的动能湍流。为了验证这一假设，提出了一个长期的实地实验，在贝加尔湖和北极基尔皮斯湖同时安装两个相同的自定义监测站，在两个湖泊的整个冬季。进行这样的实验和分析其结果需要将项目延长12个月。实验结果将提供关于不同湍流产生机制下的冰边界层动力学的详细信息。如果被证明是有效的，建议的缩放将允许量化的冰水热交换在很宽的范围内的条件下，并可以直接应用于模拟的冰水边界层在极地海洋学和湖泊的冰盖。

The ongoing project is focused on quantification of physical processes, which determine formation and melting of seasonal ice cover. The project is a German-Russian collaborative effort, which combines research on European Arctic lakes and on Lake Baikal. At the initial stage of the project, analysis of results from massive field campaigns revealed the crucial role played by under-ice water motions---geostrophic currents and short-term seiche oscillations---in acceleration of melting at the ice base. These results led to formulation of a unifying hypothesis on scaling the water-ice heat flux with the dissipation rate of the kinetic energy of turbulence. In order to test the hypothesis, a long-term field experiment is proposed based on installation of two identical custom monitoring stations simultaneously in Lake Baikal and in arctic Lake Kilpisjärvi for the entire winter period in both lakes. Performing of such an experiment and analysis of its results requires a 12-month extension of the project. The outcomes of the experiment will provide detailed information on the ice boundary layer dynamics under different mechanisms of turbulence generation. If proven valid, the proposed scaling will allow quantifying the ice-water heat exchange in a wide range of conditions, and can be directly applied for modeling the ice-water boundary layer in polar oceanography and limnology of ice-covered lakes.