Abstract: Using the reconstructed 500 hPa geopotential height data in 1880-1950 and the 500 hPa geopotential height reanalysis data from NCEP/NCAR in 1951-2004, the characteristics of the atmospheric circulation in East Asia on the interannual scale were analyzed. A prominent meridional teleconnection mode of 500 hPa positive-negative-positive height anomaly (P-N-P) from north to south was found along the east-coast of East Asia in summer. The mode reflects the in-phase variations in Okhotsk blocking high and west Pacific subtropical high. The relationship of the circulation mode with the summer precipitation in eastern China was also studied. The results show that the P-N-P anomaly circulation mode correlates well with the precipitation in the middle and lower reaches of the Yangtze River and Northeast China on the interannual scale. When the blocking high becomes stronger, and the subtropical high locates southward and is stronger than normal, the precipitation in the middle and lower reaches of the Yangtze River and Northeast China is above normal.

Key words: Circulation in East Asia, summer preciation, interannual variation