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

正在进行的项目侧重于物理过程的量化，这些物理过程决定了季节性冰盖的形成和融化。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。在该项目的初始阶段，对大规模实地运动的结果的分析揭示了冰下水运动-地转流和短期海冰振荡-在加速冰基融化方面发挥的关键作用。这些结果导致了一个统一的假设，即用湍动能的耗散率来衡量水-冰热通量。为了验证这一假设，在贝加尔湖和北极湖基尔皮斯耶尔维湖同时安装了两个完全相同的定制监测站，并在这两个湖的整个冬季进行了长期的现场实验。进行这种实验并分析其结果需要将该项目延长12个月。实验结果将提供不同湍流产生机制下冰边界层动力学的详细信息。如果证明有效，建议的定标将允许在广泛的条件下量化冰-水热交换，并可直接用于极地海洋学和冰盖湖泊的湖湖学中的冰水边界层模拟。

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.