报告人：Dan Li, Boston University

报告摘要：In 1926 Ira Bowen published a seminal paper on lake evaporation in which he linked the ratio of sensible to latent heat fluxes (nowadays known as the Bowen ratio) to the ratio of vertical gradients of temperature and vapor pressure. 90 years later we revisit the key assumption in Bowen’s method, that is, the equality of heat and vapor eddy diffusivities, from a turbulence perspective. It is shown that such assumption is consistent with the active role of temperature in turbulence generation or destruction even when perfect similarity between turbulent transport of heat and water vapor is absent.

Another important approach for estimating evaporation from water surfaces is the Priestley-Taylor (PT) method, which requires an empirical coefficient (often called the PT coefficient). Although this coefficient is often assumed to be about 1.26, its variability, especially at short time scales, is largely unknown. In this talk, the variability of the PT coefficient is linked to the dissimilarity between turbulent transports of heat and water vapor. A new method that allows the determination of PT coefficient operationally using standard meteorological sensors is proposed and tested.

报告人简介：Dan Li is an Assistant Professor in the Department of Earth and Environment at Boston University. He received his Bachelor degree in Hydraulic Engineering in 2009 from Tsinghua University and his PhD in Civil and Environmental Engineering in 2013 from Princeton University. Before joining BU, he worked as a postdoctoral research associate in the Program of Atmospheric and Oceanic Sciences at Princeton University and as a visiting scientist in the Geophysical Fluid Dynamics Laboratory.

报告时间：2016年8月4日（周四）上午10: 00 

报告地点：地理科学馆411会议室

主持人：  汤秋鸿 研究员

陆地水循环及地表过程院重点实验室

2016-07-28