Seasonal Highlights

Climate in China

During 2006-07 winter (Dec. 2006 – Feb. 2007), China mean surface air temperature was 1.9℃ above normal and it was the second highest in historical record. Positive temperature anomalies were over 1℃ in the whole country except near-normal temperatures in eastern Southwest China and the upper Huanghe River basin. Meanwhile, 2-4℃ positive temperature anomalies were observed in most of north China, with 4-6℃ above normal temperatures in parts of Heilongjiang and Jilin. For the season, precipitations were over 30% more than normal in parts of northern Northeast China, western Inner Mongolia, the middle reaches of the Yangtze River, most of Yunnan, western Sichuan, the upper Huanghe River basin and central Tibet. Near or below normal precipitations were found in the rest regions, with precipitations over 30% less than normal in southern Xinjiang, western Gansu, southwestern Northeast China, the eastern Huabei area, and the southern Huanan area, and even almost without any precipitations in parts of aforementioned areas.

Climate in the World

During 2006-07 winter, a warm climate was dominant in the world. Except around 1℃ less than normal temperatures in western America, most of West Asia, locations of Far East, northeastern and its western coastal areas, and the western America, temperatures were above or near normal in the other areas of the whole world with temperatures over 2℃ higher than normal in most of the Eurasia continent, and even 4-6℃ above Normal in its mid latitudes.

For the winter, there was an irregular rainfall distribution globally. Precipitations were over 30% more than normal in most of mid-high latitudes of Eurasia, central and Northeastern China, the northwestern Indian subcontinent, central America, and most of southern South America, and even 1-4 times in locations. Meanwhile, near or below normal precipitations scattered over the rest areas with precipitations over 50% less than normal in Turkey, Central Asia, parts of East Asia, most of the Indian subcontinent, West Africa, South Africa, most of Australia, Alaska, western America, and coastal areas of northern South America, and even without precipitations in some locations.

General Circulation Features

Northern Hemisphere: During 2006-07 winter, the mean 500-hPa geopotential height field exhibited 3-wave pattern. In the height anomaly field, less than -4 dam anomalies controlled northern Europe, northeastern North America and its nearby ocean, and eastern Siberia. Heights were near or more than normal in the other regions. The subtropical high over the northwest Pacific was stronger and larger than normal.

Southern Hemisphere: In the mean 500-hPa geopotential height anomaly field, except that the extremity of South America was covered by less than -4 dam, the values were near or more than normal in the rest areas with values above 4 dam in the southeastern South Pacific and the ocean portion south of Australia.