Seasonal Highlights

Climate in China

During Spring 2009 (March-May), mean surface air temperatures were at least 1℃ above normal in most of China, with at least 2℃ above normal in parts of northern Northwest China, central-western Inner Mongolia and locations of eastern Inner Mongolia, locations of western North China. Temperatures were at least 0.5℃ below normal in southern Hainan.

For the season, Precipitations were observed at least 30 -100% more than normal in the most central and northern Tibetan Plateau and locations of the south, central Inner Mongolia, southern North China and northern Huanghuai, locations of northern Xinjiang and locations of southern Northeast China, with at least 200% above normal in locations. Meanwhile, precipitations were observed 30-80% below normal in most southern Xinjiang, western Inner Mongolia and parts of the east, locations of northern Northeast China, parts of southwestern and southeastern Tibet, locations of lower reaches of the Yangtze River and locations of eastern South China，with no precipitation in parts of southern Xinjiang and locations of western Inner Mongolia .

Climate in the World

During Spring 2009, seasonal mean surface air temperatures mainly featured above normal in most of the world. Mean surface air temperatures were observed at least 1℃ above normal in northwestern and southwestern Europe, eastern and southern Russia, most East Asia, regions from central and southern Central Asia to most West Asia, parts of western and southern Africa, southwestern North America, parts of northern and southern South America, locations in central and northern Australia, with temperatures 2-4℃ above normal in eastern Siberia, Mongolia and parts of northern East Asia, locations of eastern West Asia, locations in northern and southern South America. Meanwhile, temperatures were at least 0.5℃ below normal in parts of southeastern Europe, locations of northwestern Russia and locations in Central Siberia, locations in Southeast Asia, northern North America and locations of Australia, with temperatures 2-3℃ below normal in parts of northwestern North America.

For the season, precipitations were observed at least 30% more than normal in most central-eastern Russia, regions from parts of southwestern Russia to northern Central Asia, most South Asia, parts of central and southern East Asia and locations of eastern East Asia, the Indo-China Peninsula, parts of West Africa, parts of northwestern and mid-eastern North America, locations of South America, with at least 100% above normal in locations. Meanwhile, precipitations were observed 30-80% below normal in parts of northern and western East Asia, parts of West Asia, parts of West Africa, North Africa and South Africa, parts of western North America, parts of southern and northern South America, most Australia, with no precipitation in locations.

General Circulation Features

Northern Hemisphere: During Spring 2009, in the 500hPa geopotential height anomaly field, positive anomalies above 4 dam covered most northern North Pacific Ocean, regions from location of northeastern Canada to locations of the northern Atlantic Ocean, parts of central and western Europe, with central values above 8 dam over parts of the northern North Pacific Ocean. Meanwhile, negative anomalies below -4 dam covered locations in western Russia and local seas south of the Greenland Island. Heights were near normal in other regions.

Southern Hemisphere: For the season, zonal circulation prevailed at the mid-high latitudes. In the 500hPa geopotential height anomaly field, positive anomalies above 4 dam covered the most middle and high latitudes south of 40°S, with central values above 16 dam over locations in the South Pole. Meanwhile, negative anomalies below -4 dam covered locations of the southeastern South Pacific Ocean. Heights were near normal in other regions.