A Surface Flux Estimation Scheme Accounting for Large-Eddy Effects for Land Surface Modeling

Abstract

We propose a surface flux estimation formula to account for large eddy effects by keeping the boundary layer depth the only added parameter. We develop a novel way to evaluate the estimation formula by using a set of independent large eddy simulations, in which the vertical extents of largest eddies affecting surface layer are confined in a wide range of depths. It is found that these confined vertical extents hold a significant linear relationship (with slope of ∼1) with the inversely estimated vertical extents of affecting large eddies. This close relationship between the two vertical extents verifies the hypothesis that the boundary layer depth is linearly relevant for accounting for large eddy effects. Moreover, the two vertical extents are found to be comparable in value. This implies that the estimation formula we propose here is likely to be valid and applicable to unstable boundary layer in general. © 2022. The Authors.