An Analysis Of Summer Precipitation Features And Anomaly In Northeast China

Based on the analysis of the Northeast China precipitation character,this paper is particularly concerned with the corresponding general circulation anomalies character of anomalies of the Northeast China floods season precipitation and the influence of SSTA on rainfall in floods season in Northeast China.The main conclusions are followed:1. Northeast China precipitation anomalies shows complex periodic variation in different years,Which shows obvious 30 decadal oscillation cycle characteristics, at the same time also has different degree period of 10 years or so.The spatial distribution of summer precipitation anomaly is mainly with the phase anomaly characteristics of more and less, at the same time there are things, north and south the phase changes.2. Northeast China floods season precipitation take place a mutation in 1970.Early late less rainfall in northeast China.3. The direct cause of precipitation anomalies is the atmospheric circulation anomaly in Northeast China. abnormal atmospheric circulation in the middle of the 7 at the end of August, the adjustment of its direct impact on the circulation of cold air in northeast area of strength; low atmospheric circulation anomalies occurred in July, it directly affects the circulation anomalies of summer monsoon in Northeast China, water vapor transport is caused by abnormal precipitation anomaly; Anomaly of ground pressure also occurs in July. If there exists abnormal negative pressure in the Mongolia area, its strength directly influences the Northeast ground pressure or cyclone activity intensity caused by abnormal rainfall in Northeast china.4. There is apparent correlation between floods season Precipitation In Northeast China and SSTA of last winter the "Key regions"(20° E-90° W,40° S-60° N). At the same time, there are positive and negative correlation between the north and south of the North Atlantic ocean. There is a negative correlation between the sea surface temperature in the key areas of the previous winter and the precipitation in the northeast of China.