Seasonal Highlights

1. Climate in China

During summer 2010, seasonal surface air temperature averaged over China was 1.1°C above normal (20.3), and was the warmest summer since 1961.Temperatures were observed more than 1°C-2°C above normal in most of Northwest China, northwestern North China, central and northern Northeastern China, Inner Mongolia, most of Tibet, western Sichuan of China, with 2-4°C above normal in Inner Mongolia and western Gangsu of China.

For the season, precipitations were observed more than 30%-80%below normal only in Inner Mongolia, central and western Gangsu of China and central Xinjiang of China. Meanwhile, precipitations were observed 300-100% more than average in western Xinjiang of China, most of Qinhai of China, southern Shanxi of China, most of Liaoning, southeastern Liaoning of China, southeastern Jilin of China, eastern Hubei of China and northwestern Fujian of China, with 100% more than normal in the parts of western Xinjiang of China.

2. World Climate

During the boreal summer, most of the world experienced a warmer season. Mean surface air temperatures were observed 1℃ above normal in most of Europe, West Asia, Central Asia, northern South Asia, northeastern and central East Asia, parts of eastern Russia, parts of northwestern Africa, eastern and southern North America and parts of northwestern South America, with temperatures 3-6℃ above normal in the region from central Europe to western Russia and parts of northern East Asia. At the same time, temperatures were observed 1℃ below normal in central Russia, most of Australia, parts of western north America and southern South America, with at least 2℃ below normal in parts of northern Russia.

For the summer, precipitation was observed at least 30%-80% more than normal in western Europe, northwestern and parts of eastern West Asia, southeastern Central Asia, northwestern South Asia, western East Asia, central and northern Russia as well as parts of southeastern Russia, northwestern Africa, central and eastern Australia, most of central North America, eastern and parts of western South America, with over 100%-200% above normal in northwestern Africa, northwestern South Asia and parts of eastern West Asia. In the meantime, precipitation was observed 30-80% below normal in the region from eastern Europe to western Russia, northern Central Asia, northern East Asia, eastern South Asia, parts of central Africa, western Australia, parts of western North America and southern and central South America, with no precipitation in locations.

3. General Circulation Features

Northern Hemisphere: During the summer of 2010, the mean 500hPa height field exhibited a 4-wave pattern at the mid-high latitudes. The positive anomalies above 4 dam covered eastern Europe, northern East Asia, northern North America, the northern Bay of Bengal and parts of eastern North Pacific Ocean, with central value above 8 dam in eastern Europe. The negative anomalies below 4 dam covered northwestern Russia. For the month, the Northwest Pacific subtropical high (NWPSH) was larger and stronger. It was located bit southward than normal and extended abnormally westward.

Southern Hemisphere: The negative anomalies covered the South Pacific Ocean, the central and eastern South Pacific Ocean and central South Atlantic Ocean, with central values above 8 dam over the central South Pacific Ocean and southeastern South Indian Ocean. Meanwhile, negative values covered the region from south of 60^oS to the polar area, with central values below -8 dam and -16 dam over southeastern and southwestern Antarctica, respectively.