Refinement of Gravel Parameterization and Its Impacts on Weather

The Tibetan Plateau (TP) 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 faster-moving vortex, with its track and structural characteristics more closely aligned with 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 in surface energy weakens atmospheric instability and convective potential, ultimately resulting in reduced precipitation and weaker vortex intensity, as indicated by lower central vorticity. 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.