Possible Linkage between Spring Extreme Precipitation over East China and Surface Sensible Heat Flux over the Eurasian Continent

Based on the ERA-20C reanalysis data and observational precipitation data collected at the 332 stations in eastern China (to the east of 105°E) during 1960-2010, the possible linkage between spring extreme precipitation over eastern China and surface sensible heat flux over the Eurasian Continent is explored. Results show that when weakened (intensified) spring surface sensible heat flux occurs in the middle latitudes of the Eurasian Continent (i.e., regions to the west of Lake Balkhash and to the north of Lake Baikal) while intensified (weakened) sensible heat occurs in eastern China, the spring extreme precipitation is usually more (less) than normal over northern China but less (more) than normal over southern China. Further analysis suggests that weakened sensible heat in the middle latitudes and intensified sensible heat in the lower latitudes tend to weaken spring subtropical westerly and shift it northward, which are favorable for enhanced convective and baoclinic instabilities, leading to more extreme precipitation in North China. However, they tend to decrease baroclinic and convective instabilities and result in less extreme precipitation in South China. On the contrary, intensified sensible heat in the middle latitudes and weakened sensible heat in the lower latitudes tend to have opposite effects.