Extreme Climate within Eastern Part of Northwest China and Its Response on Sensible Heat over Qinghai-Tibetan Plateau

The extreme climate has been studied by area-weighted and area-averaged precipitation and mean temperature measured at 100 observational stations within the East part of the North-West China(ENWC).The results support that it is the most important for the extreme drought and flood in the ENWC that the pattern of Westerly belt circulation over the Asia region and the position of the West Pacific Subtropical High(WPSH) at 500hPa.During flood years,the meridional circulation predominates over the Asia region,the size of the trough over East Asian is eastward and WPSH is northward.During drought years,zonal circulation predominates over that of the meridian,the size of the trough over East Asian is more westward,WPSH is more southward.The polar vortex and circulation type over the Europe-Asia region are the same important for the cold and warm in the ENWC,as well as the Westerly belt circulation type over the Asia and the West Pacific Subtropical High(WPSH) at 500hPa.During extremely high temperature years,the polar vortex was weaker than normal.Zonal circulation predominates over that of the meridian over the Europe-Asia region.The WPSH is obviously weaker and smaller than the normal;its position is more southward.During extremely low temperature years,the circulation character is opposed to that of the extremely high temperature years.There is a better correlation between the sensible heat flux over Qinghai-Tibetan Plateau in winter and the precipitation and temperature in summer within ENWC than that of in spring.