当前位置: X-MOL 学术Math. Comput. Simul. Dyn. Atmos. Ocean. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
A modeling study of the influence of initial soil moisture on summer precipitation during the East Asian Summer Monsoon
Dynamics of Atmospheres and Oceans ( IF 1.9 ) Pub Date : 2019-03-01 , DOI: 10.1016/j.dynatmoce.2018.12.003
Shi Zhong , Tao Yang , Jian Zhu , Futing Wu

Abstract The state-of-the-art WRF model is used to investigate the impact of the antecedent soil moisture on subsequent summer precipitation during the East Asian summer monsoon (EASM) period. The control experiment with realistic soil moisture condition can well reproduce the seasonal pattern from low- to high- atmosphere, as well as the spatial distribution of precipitation belt in East China. Compared with the control experiment, the sensitivity experiment in which the initial soil moisture is reduced generates more precipitation along the East China Sea, and less rainfall over both Central and South China. This suggests that the effect of initial soil moisture on monsoonal precipitation in East China is regionally dependent. The influence on precipitation is mostly attributed to the change in precipitation from mid July to late August. The initial soil moisture condition plays a role in changing the seasonal pattern and atmospheric circulation due to the weak heating and geopotential gradient, leading to a reduction in southeasterly flow and moisture flux from South China Sea. The changes between DRY and CTL runs result in reduced southerly wind over the ocean (south of ˜25 °N) and enhanced northerly wind over the land (north of ∼25 °N). The temperature and associated circulation changes due to drier initial soil moisture anomaly result in reduced southerly winds over East China, and therefore a weakened EASM system. The averaged moisture flux decreases significantly over Central China but increases along the East China Sea. In addition, the drier soil moisture perturbation exerts an effect on suppressing (enhancing) vertical velocity over Central China (along the East China Sea), thus leading to more (less) cloud water and rain water. Therefore, the influence of soil moisture exerts an opposite impact on surface precipitation between these two regions, with more and less accumulation rainfall in Central China and along the East China Sea, respectively.
更新日期:2019-03-01
down
wechat
bug