Seasonal Highlights

Climate in China

During the boreal autumn (September-November), mean surface air temperatures were at least 1-2℃ above normal in Yunnan, Tibet, Qinghai, western Sichuan. Meanwhile, the temperatures of most North China, most Northeast China, western Huanghuai and central-eastern Inner Mongolia were slightly below normal.

For the autumn, precipitations were less than normal in most China. Precipitations were observed 30-50% below normal in most Southwest China, western Jiangnan, Jianghan, central Inner Mongolia, northeastern Heilongjiang and eastern Shandong. Only the precipitations for central and western Northwest China, central North China, parts of southwestern Tibet and Hainan were 30%-200% more than normal.

World Climate

During the boreal autumn, most of the world experienced a warmer season. Mean surface air temperatures were observed at least 0.5℃ above normal in most Europe，southern West Asia, parts of South Asia, southwestern China, Australia, most Africa, most North America and most South America, with temperatures 2-3℃ above normal in some regions. At the same time, temperatures were 0.5～1℃ below normal in northern East Asia, most Siberia, central-southern North America and southern South America, with at least 1℃ below normal in Central Siberia.

For the season, precipitations were observed at least 30% more than average in eastern and southern South Asia, northwestern China, parts of eastern Russia, northwestern West Asia, northwestern Africa, southeastern North America and southeastern South America, with over 100% above normal in locations. In the meantime, precipitations were observed 30-80% below normal in southern China, northwestern South Asia, most West Asia, most Australia, western North America, eastern Alaska and parts of central South America.

General Circulation Features

Northern Hemisphere: During the autumn of 2009, in the mean 500hPa height anomaly field, the above 4 dam positive centers were located over the Uralskiy Khrebet, Kara Sea and northeastern North America Meanwhile, negative anomalies with the center below -4 dam dominated the northeastern Pacific. Most of other regions tended to be near normal.

Southern Hemisphere: In the anomaly field, the obvious positive anomalies dominated the most regions south of 60^oS latitude, with the center value above 4 dam. Meanwhile, negative anomalies below -4 dam were located in southern South America.