The Linkage between the Winter-Spring Arctic Oscillation and the Precipitation over the Western and the Central China

Based on the CPC Merged Analysis of Precipitation (CMAP) datasets and the Arctic Oscillation(AO) Index from 1979 to 2016, the influence of AO on the winter-spring (from January to March) precipitation over the western and the central China is studied. Results show that: (1) There is a significant correlation between the winter-spring AO and the precipitation, but the relativity of AO and precipitation is gradually weakening with time in the period over two areas. (2) In the years with the strong AO index, the precipitation declines over the region Ⅰ (40°N-45°N，70°E-82°E), while it increases over the region Ⅱ (17°N-42°N，97°E-117°E). (3) When AO is enhanced, the Siberian high and the Polar vortex are enhanced with it, and the wind field and the humidity field over the east Asia are also changed so evident that the precipitation distribution over the western and the central China are thus changed. The winter-spring AO is closely related to the precipitation, and it can provide the useful signals for the forecast of precipitation over the western and the central China.