Coupling Soil Gravel Parameterization Into WRF: A Case Study of the Tibetan Plateau Vortex

Abstract

The Tibetan Plateau has substantial dynamic and thermal effects on regional and global climate, with plateau vortices (TPVs) playing a key role in summer precipitation. However, current land surface models often overlook the influence of gravel on soil hydrology and thermodynamics, which may influence vortex evolution. In this study, we incorporated the influence of gravel on soil properties into the Weather Research and Forecasting (WRF) model to explore its effect on TPV dynamics. Two simulations were conducted: one without gravel parameterization (WRF-Ctl) and one with gravel (WRF-Gravel). Results showed that WRF-Gravel produced a more rapidly developing vortex with better alignment to observational data in terms of position and scale. Sensitivity experiments with gravel content set to 0%, 50%, and 100% indicate that increased gravel content enhances soil permeability, reduces soil moisture, and decreases surface latent heat flux. This reduction weakens atmospheric instability, limits convective energy, and leads to reduced precipitation and vortex intensity. While these results provide preliminary insights into the potential role of gravel in modulating TPV thermodynamic and dynamic processes, further multi-case and long-term studies are needed to validate these findings and assess their broader applicability.