Dynamics of water temperature and interfacial heat flux in lake ice and under-ice layers

The purpose of this study is to understand the temperature dynamics of ice and lake water under ice during ice growth. A vertical temperature monitoring system for ice and water under ice was employed for the first time in Wuliangsuhai Lake from 20 December 2016 to 15 March 2017 to obtain continuous monitoring temperature data necessary for calculating the heat flux density at the ice–water interface. During the ice growth period, the ice body temperature and the water body temperature under the ice show an obvious rising trend from the upper layer to the lower layer. As the ice body enters the melting period, the ice temperature and the water temperature under the ice begin to change rapidly. In the presence of snow over the ice, the fluctuations of ice temperature and water temperature under the ice remain stable. According to the experimental data, the analytical equation derived from the Stefan condition is used to calculate the heat flux at the intersection boundary of ice body and water body under ice, which varies from 1.73 to 19.6 W/m2. The dynamic change of ice thickness is significantly influenced by the temperature of ice and water and the heat flux density at the ice–water interface.