Air-Lake interaction features found in heat and water exchanges over Nam Co on the Tibetan Plateau

Abstract

The central Tibetan Plateau contains numerous lakes, the largest and deepest of which is Nam Co. Heat and water budgets over Nam Co were estimated throughout the year. Latent and sensible heat fluxes from the lake are very small from spring to summer and larger from fall to early-winter. Although the land surface over the Tibetan Plateau supplies heat energy to the atmosphere during the premonsoon and monsoon periods, a deep lake such as Nam Co releases a large amount of heat in the post-monsoon period. Annual evaporation from the lake was 658 mm, much larger than the annual rainfall of 415 mm and also more than two times the annual evaporation from the land surface. The diurnal variation of surface-air temperature difference over the lake showed a reverse phase of that over land in the monsoon period, a condition that likely affects the convective activity over the lake.