资源环境科技发展态势分析平台

Open water surface evaporation (E) or the latent heat flux (λE) is of great importance to surface water and energy budget. However, partitioning of the available energy into sensible heat flux (H) and λE, quantified as the Bowen ratio (), is implicitly discrepant between models and observations. In this study, an explicit equation for the estimation of Bo (thus for the λE) is derived based on an atmospheric boundary layer (ABL) model combined with the potential vapor pressure deficit (VPD) budget. This equation only requires the air temperature (T_a) and specific humidity (Q) as input, and performs well in λE estimation with a relative error of <1% over observations of global sea and inland lake surfaces. More importantly, this equation clearly expresses the physical relationship between Bo and air temperature and humidity, thus revealing the mechanism of water surface energy partitioning in response to external environmental variables.