Numerical Simulation Of The Impacts Of Abnormity Of Spring Surface Heat Flux Over The Mid-High Latitudes Of The Eurasian Continent On Summer Climate In China

Driven by the re-analysis data of NCEP/DOE NCEP/DOE Reanalysis Ⅱ, we have used the latest version of the Abdus Salam International Centre for Theoretical Physics (ICTP) regional climate model RegCM4.4.5.7 to design experiments based on different surface heat flux factors to study the impact of abnormity of heat flux over the mid-high latitudes of the Eurasian Continent on summer climate in China after selecting the better land surface scheme. Conclusions can be summarized as below:1) The RegCM4.4.5.7 has been used with two different land surface schemes to simulate the spring and summer climate of China. After comparing with the observational data, the results show that both two schemes have described surface temperature well. BATS1e schemes shows higher than the observational data. And CLM3.5 simulates better than BATS1e and more close to the actual facts and has a very good simulation of low temperature zone. The simulation results of precipitation shows that the two schemes couldn’t reach the same effect of temperature. BATle simulations shows higher than the observed average value and CLM3.5 simulations are close to the facts. Based on these results, this article will choose the land surface scheme CLM3.5 coupled regional climate model to run the sensitive experiments.2) After the spring sensible heat flux over the mid-high latitudes of the Eurasian Continent has been enhanced, the summer precipitation is more in Yangtze River and Northeast China, and less in North China and the temperature is lower in Yangtze River and Northeast China, and higher in North China. After spring sensible heat flux enhanced, the local air temperature will rise, which leading to abnormity of height field and circulation. Yangtze River Valley and the northeast region appear cyclonic circulation and strong convective activity combined with adequate moisture conditions, leading to more rainfall. On the contrary, North China has anticyclone and weak convective resulting in less rainfall. The anomalies of mid-high latitudes of the Eurasian surface sensible heat flux can be an important factor on summer climate in China.3) After the spring snow water over the mid-high latitudes of the Eurasian Continent has been increased, the results show that snow anomaly in spring can cause more summer precipitation and lower temperature in Yangtze River and Northeast China. When there are less spring snowmelt and more left snow water, the summer snow water will be increased which will cause lower local temperature. The range of cold low will extend from mid-high latitudes to mid-low latitudes which can make the atmospheric circulation of East Asia have adjustments. At last, summer climate of China will be changed.