Evaporation and surface energy budget over the largest high-altitude saline lake on the Qinghai-Tibet Plateau

Interactions between lakes and the atmosphere at high altitudes are still poorly understood due to difficulty in accessibility of direct measurements. This is particularly true for the Qinghai-Tibet Plateau (QTP), where approximately 50% of the lakes in China are located. Continuous direct measurements of the water flux and surface energy budget were made over the largest high-altitude saline lake in China, Qinghai Lake on the northeastern QTP, using the eddy covariance method from 11 May 2013 to 10 May 2015. Results indicated that annual evaporation of Qinghai Lake was 832.5mm for 2013/2014 and 823.6mm for 2014/2015, respectively. The surface energy budget and evaporation showed a strong seasonal pattern, with peaks in the latent and sensible heat flux observed in autumn and early winter. There was a 2-3 month delay between the maximum net radiation and maximum latent and sensible heat fluxes. Intraseasonal and seasonal variations in latent and sensible heat flux were strongly affected by different air masses. Westerly cold and dry air masses increased evaporation while southeast moist air mass suppressed evaporation, suggesting that the lakes might serve as an air conditioner to modify the temporal heat and water flux in the QTP.