[A-AS10] Land-Atmosphere interactions and precipitation variations over the Asian monsoon region.

[AAS10-P18] The freeze-thaw cycle and key parameters in a Tibetan Plateau lake using LAKE2.0 model and field observation

*Zhaoguo Li¹, Shihua Lyu², Lijuan Wen¹, Lin Zhao¹, Xianhong Meng¹, Yinhuan Ao¹ (1.Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, 2.School of Atmospheric Sciences, Chengdu University of Information Technology)

Keywords:lake ice, snow, albedo, extinction coefficient

Few studies have paid attention to the freeze-thaw process of Tibetan Plateau (TP) lakes and key control parameters. By combining 216 simulation experiments using a LAKE2.0 model with the observation, we evaluated the effects of ice and snow albedo, ice and water extinction coefficients on the lake ice phenology, water temperature, sensible and latent heat fluxes in Ngoring Lake. The increase of ice albedo, snow albedo and the ice extinction coefficient (K_di) induce significant decrease in water temperature. Compared with the latent heat, the sensible heat flux is more sensitive to these three parameters. With the decrease in high K_di, the ice thickness, water temperature and frozen days present an extensive increase. If K_di less than 2.5 m^-1, the increase of ice thickness is no longer obvious. In the frozen period with little snow, the K_di exhibit little influence on frozen days. The frozen days is significantly affected by the snow albedo and changes fastest in the snow albedo from 0.5 to 0.75.