Quantifying Surface Energy Fluxes and Evaporation over a Significant Expanding Endorheic Lake in the Central Tibetan Plateau

Abstract

In this study, energy and water vapor exchange between the lake and atmosphere over the largest lake in Tibet, Lake Serling Co, was measured by an eddy covariance system from 26 April to 26 September 2014. The results showed that the diurnal variations of sensible heat flux (H) and latent heat flux (LE) were different to that of net radiation (R_n). R_n reached its peak value at the local noon, whereas H peaked in the morning and LE reached the peak in the afternoon. On a seasonal scale, H and LE were also different from R_n. The maximum R_n occurred in June, while the maximum of H and LE were observed in September. The lake evaporation was quantified with daily mean value 2.7 mm d⁻¹ and a total amount of 417.0 mm. Besides, evaporation from Lake Serling Co was also compared with two kinds of pan evaporation (D20 pan and E601B pan) and potential evaporation on land surface. The variability of conversion coefficients between lake evaporation and D20 pan, E601B pan and potential evaporation indicate that coefficients varied depending on the month and could not be defined as a single experimental value.