Numerical Study of Initial Soil Moisture Impacts on Regional Surface Climate
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Abstract
In this paper, the impacts of initial soil moisture (SM) over the Huaihe River Basin of China on the summertime climate have been investigated with a regional climate model. Three fourth-month-long simulations are made for two summers, the abnormal flooding in 2003 and normal climate in 2004. Besides control simulations (noted as CTL), sensitivity experiments have been conducted by assigning the initial soil moisture equals to 50% and 150% of the simulated soil moisture while keeping the others unchanged, which are noted as SM50 and SM150, respectively.The results show that effects of initial SM anomalies at late spring can last for the whole summer, and the increase of initial soil moisture (SM150) has more significant effects than the decreased one (SM50). The differences between sensitivity experiments and CTL mainly appear at surface and near-surface atmosphere. When increasing the initial SM, the latent heat flux and surface soil moisture are increased, correspondingly the sensible heat flux, temperature and radiation are all decreased. The changes of rainfall are not distinct between SM50 and SM150, which might be related to the processes within atmosphere, especially the humidity pattern.
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