A Teleconnection Pattern Related with the Development of the Okhotsk High and the Northward Progress of the Subtropical High in East Asian Summer

This study examines the relationship between the subtropical high in the West Pacific and the Okhotsk high in summer, and explains why the subtropical high cannot progress northward when the Okhotsk high is active. The findings are as follows. (1) A teleconnection pattern, namely, the significant correlation dipole between the index of the Okhotsk high and 500 hPa geopotential height (Z500), over East Asia, tends to occur in summer. (2) The teleconnection is closely related to the wave train propagation from the Okhotsk Sea via Japan to the subtropical regions when the Okhotsk high is developing. (3) The wave train propagation associated with the development of the Okhotsk high can generate a large cyclonic anomaly over the sea east of Japan, even in late summer. The cyclonic anomaly plays an important role in weakening the northern part of the subtropical high. The anomalous southern position of the main body of the subtropical high in the summer of 1998 is partly due to this effect.