Seasonal Highlights

Climate in China

During Autumn 2007, mean surface air temperatures were mainly above normal in most of China, except for southeastern Southwest China, western South China and parts of western Xinjiang. Temperatures were observed 1℃ above normal in northeastern Xinjiang, mid-eastern Inner Mongolia, central-northern Northeast China, most of the Tibet Plateau, parts of eastern East China, with more than 2℃ above normal in parts of eastern Xinjiang and northeastern Inner Mongolia.

For the season, precipitations were observed 30-50% less than normal in most of northeastern China, most of eastern China and northern Xinjiang, with 80% below normal in parts of above regions. Meanwhile, precipitations were observed 30-50% above normal in most of Northwest China, central North China and eastern East China, with more than 100% above normal in parts of above regions.

Climate in the world

During Autumn 2007, mean surface air temperatures were observed near or above normal in most of the world except for northwestern America and central Europe with more than 1℃ below normal. Mean surface air temperatures were observed 1-2℃ above normal in most of the Eurasia continent, northern Africa, most of Australia, central North America and Alaska, most of South America, with 2-6℃ above normal in most of Siberia and Alaska.

For the season, precipitations were observed 30-50% above normal in central Europe, Northwest China, central North China, eastern East China, northern Siberia, eastern South Asia, northern North America and coasts of southwestern Alaska, coasts of northern South America, West Africa, northern South Africa, parts of coasts of northern South Africa and locations of eastern Australia, with more than 100% above normal in locations of above regions. Meanwhile, precipitations were observed 30-80% below normal in southern Europe, most of West Asia, most of South Asia, southern Siberia, most of Central Asia, Northeast China and eastern China, southern and eastern North America and mid-western Australia, with no precipitations in locations of above regions.

General Circulation Features

Northern Hemisphere: During Autumn 2007, the mean 500hPa geopotential height field exhibited a 4-wave pattern at the mid-high latitudes. In the 500hPa height anomaly field, positive anomalies above 4 dam covered the northern South Atlantic, parts of the Arctic Ocean, areas near the Ural Mountains, the northeastern North Pacific and parts of central America, with central values more than 12 dam above normal in northern North Atlantic. Meanwhile, negative anomalies below -4 dam covered the Bering Strait and northeastern North America.

Southern Hemisphere: For the season, zonal circulation prevailed at the mid-high latitudes. In the 500hPa height anomaly field, positive anomalies more than 4 dam above normal covered seas around the Antarctica and the southeastern South Pacific. Meanwhile, negative anomalies more than -4 dam below normal covered parts of mid-high latitudes (40-60ºS) of Southern Hemisphere, with central value more than -8 dam below normal over oceans in south of South Africa.