Abrupt Climate Changes Observed in Late August over Central Japan between 1983 and 1984

Abstract

Interdecadal climate changes occurring during the latter half of August (LA) in central Japan are described, and the associated changes in rainfall, typhoon tracks, and circulation patterns over East Asia and the western North Pacific (WNP) regions are investigated. Since 1984, rates of sunshine and temperature have increased, while rainfall has decreased significantly during LA in central Japan. In contrast, rainfall over the Southwest Islands, northern part of Taiwan, and in the south of the middle and lower reaches of the Yangtze River in China has increased. Changes in the positions and tracks of typhoons are responsible for these changes. Prior to 1983, many typhoons approached the central-western part of Japan during LA, while after 1984, most typhoons were deflected away from Japan and moved northwestward to Taiwan and China. The North Pacific subtropical high during LA extended more westward after 1984, which affected the interdecadal changes in sunshine, temperature, rainfall, and typhoon tracks, not only in central Japan, but also over East Asia and the WNP regions.