The Influence of Horizontal Thermal Advection on Near-Surface Energy Budget Closure over the Zoige Alpine Wetland, China

Abstract

Near-surface energy budget closure has been a trending topic in land surface processes research, especially on the underlying surfaces of heterogeneous wetlands. In this investigation, the horizontal thermal advection caused by thermal inhomogeneity over the alpine wetland is calculated based on the eddy covariance data observed at the Flower Lake observation field and WRF modelling data over the Zoige alpine wetland, China. The contribution of horizontal thermal advection to the near-surface energy closure is analysed. The results show that the mean horizontal heat advection of the Zoige wetland is 20.2 W·m−2, and the maximum value reached 55.0 W·m−2 in the summer of 2017. After introducing thermal advection into the near-surface energy balance equation, the near-surface energy closure ratio increased from 72.3% to 81.0%.