Northern Hemisphere Atmospheric Circulation Characteristics in Summer 2017 and Its Impact on Weather and Climate in China
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
During the summer of 2017 (June to August), the average precipitation over China was 348.6 mm, which is 8.1% more than the climate mean (332.6 mm). Two rainfall belts were observed over eastern China. The average temperature in summer was 21.7℃, which is 0.8℃ higher than the climate mean (20.9℃). The summer of 2017 is the second warmest since 1961. The East Asian summer monsoon (EASM) was weaker than normal, while the West Pacific subtropical high (WPSH) was significantly stronger than normal with southward ridge position. The anomalous Philippine Sea anticyclone controlled the lower troposphere. The “-+-” circulation pattern was located in Eurasian midhigh latitude, with negative anomalous over Ural Mountain and near Japan and positive anomalous over Baikal Region. Circulation configuration of low latitudes and midhigh latitudes resulted in anomalous convergence of moisture flux and more precipitation over the south of the Yangtze River. Further analysis indicated that the interdecadal strengthening of West Pacific subtropical high and the sea surface temperature anomalies over the central and eastern tropical Pacific changing from negative to positive are the important cause for the significantly more precipitation over the south of the Yangtze River.