Application of the Analytic Model Based on Energy Balance into the Lake Ice Simulation of Qinghai Lake

Abstract

Lake ice is sensitive to climate change.Under the background of global warming， lake ice is generally declining， and even some lakes in the Northern Hemisphere may not freeze in the future.Lakes are widely distributed in the Qinghai-Xizang Plateau， but there are few studies on lake ice simulation.In addition， the understanding of lake ice characteristics and its freezing coefficients on the Qinghai-Xizang Plateau is still relatively limited.The freezing coefficient A0 of Qinghai Lake was calculated by the degree-day approach for ice growth， using the lake ice thickness measurement data from fly-by-wire radar， meteorological observation data of Qinghai Lake， ERA5-Land reanalysis data， MODIS land surface temperature data and Aqua/MODIS satellite remote sensing images.The results show that A0 has spatial and temporal heterogeneity in Qinghai Lake， and the former is more obvious than the latter.Both the degree-day approach and the energy balance-based analytical model are applied to simulate the lake ice evolution of Qinghai Lake on the Qinghai-Xizang Plateau.The results show that， compared with the degree-day method， the simulations of the start of ice formation， the end of melting and the thickness of lake ice for the 2018 -2019 ice season of Qinghai Lake by the energy balance-based analytic Model are more consistent with the observations.The analytical model is a better method than the degree-day method for simulating the ice of Qinghai Lake.It incorporates the effects of radiation， energy exchange， meteorological elements， lake depth and other factors， thus improving the physical processes and compensating for the fact that the accuracy of the degree-day method of simulation depends on the first date of freezing and cannot simulate the melting process.

Keywords

• qinghai lake
• lake ice freezing and melting
• ice thickness
• the degree-day approach
• the analytic model