The improvement of a regional climate model by coupling a land surface model with eco-physiological processes: A case study in 1998

The Atmospheric-Vegetation Interaction Model (AVIM) is coupled with a Regional Integrated Environment Modeling System (RIEMS) to improve the regional simulation of climate variables. A case study in 1998 is implemented to study the improvement mechanism through land-air interaction in East Asia, especially in Asian summer monsoon regions. The coupled model reduces the warming bias in July in East China through the surface heat fluxes changes. Compared to the original model of RIEMS, the strong precipitation of eastern China in July is weakened by coupling of the interactive vegetation. The surface heat flux in uncoupled model is remarkably overestimated in these regions, and the enhanced heating from land surface, particularly with latent heat flux in July, will produce the overestimated temperature and precipitation in East China. Through coupling AVIM with RIEMS, the simulated area-averaged latent heat flux of two key regions decreases (e.g. from 132.36 to 103.13 W/m2 over the region 1 between 105–125°E and 20–40°N) in July, which makes the overestimated temperature and precipitation declined, respectively.