Abstract:It is of great importance to study winter precipitation because it can directly affect agricultural production and public travel,and even threaten human safety.For lack of researches on winter precipitation,especially in North China,this paper mainly focuses the distribution and evolution of winter precipitation in North China.Based on the winter precipitation data at 160 stations in China,the NCEP/NCAR reanalysis data and the NOAA ERSST data during 1951/1952-2012/2013,the characteristics of winter precipitation anomaly in North China and its relationship to atmospheric circulation and sea surface temperature(SST) are studied.Common statistical methods including EOF reanalysis,synthesis analysis and correlation analysis are effectively used.The overall characteristics of winter precipitation indicates that although the total amount of precipitation is small,the precipitation variability is large in North China.EOF analysis results show that there are characteristics of uniform change of the whole area for winter precipitation in North China,and the interannual variability is large,with 2-4 years period.Based on the winter precipitation index defined by the data of 19 representative stations in North China,the more and less winter precipitation years are obtained.During the more(less) precipitation years,Siberian high is weaker(stronger),Aleutian low is weaker(stronger),and the northwest cold air is also weaker(stronger).At 850 hPa,the prevalent northwest wind in North China is weaker(stronger),East Asian winter monsoon dominating North China is weaker(stronger) simultaneously,and the southerly(northerly) wind anomaly also exists in North China.At 500 hPa,East Asian trough and Ural ridge are both weaker(stronger),the blocking system in mid-latitudes is weaker(stronger),and the flat westerly current(strong northwest wind) anterior the ridge takes control.Furthermore,two dominating water vapor transport channels that affect North China winter precipitation are found:one from South China Sea,and the other from the western Pacific to the east of South China Sea.The relationship between North China winter precipitation anomaly and sea surface temperature is also studied.The significant positive correlation between North China winter precipitation and previous summer(contemporaneous winter) SST locates in the westerly drift region to east of Japan(the Yellow Sea and Bohai Sea region).