Gravel Parameterization Scheme and Verification Using BCC_CSM

Abstract The soil in China contains an abundance of gravels, but it is poorly described in land surface models. To solve this problem, the Beijing Climate Center Atmosphere–Vegetation Interaction Model (BCC_AVIM), which is a land surface model with the gravel parameterization, is coupled to the Beijing Climate Center System Model (BCC_CSM). The simulation ability of BCC_CSM for China using the gravel parameterization is evaluated by comparing the simulation results using original and new schemes with the observed data. The results show that the annual average surface temperature simulated with the new scheme is more consistent with the observation in terms of the spatial distribution, and the simulation results in Southwest China, Northwest China and the Qinghai-Tibet Plateau are significantly improved, especially in summer. In the perspective of the area-averaged variables, the situation of more precipitation simulated using the original scheme is improved except for summer. The high-level and low-level wind fields simulated by BCC_CSM have a significant improvement in the Qinghai-Tibet Plateau. In general, this gravel parameterization is more suitable for areas with the high gravel content, and it improves the simulation performance of BCC_CSM in some areas of China.