Numerical Simulation of the Influence of Soil Gravel Parameterization on the Formation and Development of a Plateau Vortex

Abstract

In order to verify the simulation ability of the gravel parameterization scheme of the land surface process model on the weather process on the Qinghai-Xizang Plateau， this paper uses the regional climate model RegCM4 coupled with the gravel parameterization scheme CLM4.5 to simulate a case of a plateau low vortex.Using the simulated 500 hPa high-altitude situation field， 2 meter temperature and humidity， and soil temperature and humidity data， combined with ERA5 data for comparative verification and analysis.The results show that the RegCM4 with the gravel parameterization scheme has a better simulation effect for this plateau vortex case； In the 500 hPa high-altitude situation field， the new scheme simulates the plateau vortex center position and the characteristics of the temperature field in the vortex zone more accurately than the old scheme； In the plateau vortex generation and development stage， the 2-meter temperature and relative humidity simulated by the new scheme are significantly more effective than the old scheme.It is strong， providing powerful conditions for the formation and development of low vortex； In the simulation of soil temperature and humidity， adding gravel to improve the thermal conductivity and hydraulic conductivity of the soil， so that the plateau vortex provides better soil thermal and water conditions； The plateau vortex extinction stage， the new scheme reduces the temperature of the shallow soil and increases the temperature of the deep soil； In the anti-cyclonic circulation area at a height of 500 hPa， the soil volumetric water content simulated by the new scheme is lower than that of the old scheme.When there is no severe weather system， there is little difference in the simulation performance of the soil volumetric water content between the old and the new scheme.In the entire life history of the plateau vortex， the new scheme is significantly better than the old scheme in the simulation of shallow soil temperature， and the first layer has the best effect in the simulation of soil volumetric water content.

Keywords

• qinghai-xizang plateau
• gravel parameterization
• regcm4
• clm4.5
• plateau vortex