Seasonal Highlights

1. Climate in China

During autumn 2012, the surface air temperature averaged over China was 9.6℃, which was 0.3℃ lower than normal (9.9℃). Seasonal mean surface air temperatures were 0.5-1℃ above normal in southwestern Xinjiang, northwestern Xizang, western Qinghai, most Yunan, most Henan and central-western Heilongjiang, with 1-2℃ above normal in locations. While temperatures were below normal in the rest regions of China, with 1-2℃ below normal in central Xinjiang, central Inner Mongolia and parts of northern North China.

In autumn, average precipitation over China was 135.1 mm, which was 12.7% above normal (119.7 mm). Precipitations were observed generally 30-100% above normal in central and eastern Inner Mongolia, Northeast China, northeastern North China, most Jiangnan and northeastern South China, 100-200% above normal in eastern Inner Mongolia, northwestern and northeastern Northeast China, with over 200% above normal in locations. Meanwhile, precipitations were observed 30-50% below normal in central-western Northwest China, western and northern Xizang, western Yunnan and western Huanghuai, with over 50% below normal in southern Xinjiang, northwestern Qinghai and western Xizang.

2. World Climate

During Autumn 2012, mean temperatures were 0.5-2℃ above normal in most Europe, western and northeastern Siberia, western Central Asia, the Indo-China peninsula, northern Africa, southwestern and northeastern North America, mid-eastern South America and most Australia, with temperatures 2-4℃ above normal in eastern Europe, northeastern Siberia and parts of central South America. Mean temperatures were generally observed 0.5-2℃ below normal in parts of central Siberia, northern East Asia, southern Africa, northwestern and southeastern North America, parts of northern South America and locations of northeastern Australia, with temperature over 2℃ below normal in eastern Alaska.

For the season, precipitations were 30% to 200% more than normal in northern and eastern Europe, parts of western, southern and eastern Siberia, northeastern and locations of southeastern East Asia, the region from southeastern Central Asia to northwestern South Asia, most West Asia, parts of northwestern Africa, locations of North America and most Alaska, parts of central and southeastern South America and locations of Australia, with precipitation over 200% above normal in southeastern Central Asia and northwestern West Asia. Meanwhile, precipitations were 30% to 80% less than normal in parts of central Siberia, northwestern East Asia, locations of West Asia, parts of northern and eastern North Africa, southwestern and locations of northeastern North America, locations of South America and most Australia, with precipitation over 80% less than normal in northwestern East Asia, parts of North Africa and parts of central Australia.

3. General Circulation Features

Northern Hemisphere: During the autumn of 2012, in the field of 500hPa height anomaly, the positive anomalies above 4 dam were located in southeastern Europe, northern Siberian, the central-northern North Pacific Ocean and the central-northern North Atlantic Ocean, respectively, with central values above 12 dam over locations of northern Siberian. Meanwhile, negative anomalies below -4 dam covered locations of northwestern Europe and the central North Pacific Ocean.

Southern Hemisphere:  For the month, in the field of mean 500hPa height anomaly, the negative anomalies covered most areas in mid and high latitudes with the central values below -4 dam over parts of the central South Pacific Ocean and locations of the southern South Indian Ocean, except the positive anomalies above 4 dam covered the parts of polar areas.