欧亚中高纬陆面感热异常影响我国夏季气候的数值模拟

使用区域气候模式RegCM4.4.5.7,通过改变春季欧亚大陆中高纬地区的陆面感热通量,对欧亚中高纬感热异常影响中国夏季气候进行模拟分析,并探讨其影响机制。试验结果表明:当春季欧亚中高纬陆面感热通量加强时,我国长江流域和东北东部夏季气温降低,降水偏多;华北地区气温升高,降水偏少。春季陆面感热增强引起近地面和对流层低层大气热力状况异常,进而导致高度场和环流场的异常,长江流域和东北地区有气旋环流,对流运动旺盛,结合充足的水汽条件,对应降水偏多,而华北地区则相反,有反气旋环流和微弱的气流辐合,对应降水偏少。研究表明欧亚中高纬陆面感热异常是影响我国夏季气候的一个不可忽视的因子。

Numerical simulation of the impacts of abnormity of surface sensible heat flux over the mid-high latitudes of the Eurasian Continent on summer climate in China

The impact of abnormity of sensible heat flux in spring over the mid-high latitudes of the Eurasian Continent on summer climate in China has been simulated using RegCM4.4.5.7. The results showed that the summer precipitation is more in Yangtze River and Northeast China and less in North China, while the temperature decreases in Yangtze River and Northeast China and increases in North China after the sensible heat flux in spring over the mid-high latitudes of the Eurasian Continent has been enhanced. The surface sensible heat flux is enhanced in spring, causing abnormity of atmospheric thermal conditions in the near-surface and lower troposphere, which further leads to the abnormality in the height field and the circulation field. Yangtze River Basin and the Northeast China appear cyclonic circulation and strong convective activity combined with adequate moisture conditions, leading to more precipitation. On the contrary, the North China has anticyclone and weak airflow convection, resulting in less precipitation. The abnormity of surface sensible heat flux over the mid-high latitudes of the Eurasian can be an important factor on summer climate in China.