5—8月青藏高原OLR年际变化及其对中国气候变化的影响

Inter-annual variability of Tibetan plateau OLR and its effects on the climate over China in May and August

使用1989—2008年NOAA/AVHR,R的OLR、中国753个台站的总云量、降水量和温度资料,采用合成分析和相关分析法,分析了5—8月青藏高原OLR的年际变化及其对中国气候变化的影响.结果表明:区域平均的青藏高原OLR在5—6月和9一11月分别达到两个峰值,而在7—8月却处于一个较低的谷值;区域平均的青藏高原5—6月和7—8月OLR距平的年际变化为1989—2002年以偏低为主(除了几个正值年),而2003—2008年以偏高为主(全部为正值年).当青藏高原5—6月OLR降低时,7—8月中国南方大陆地区总云量增多、降水量增加、温度下降,而中国北方和东南沿海地区总云量减少、降水量减少、温度上升.当青藏高原7—8月OLR降低时,7—8月中国西南地区总云量增多、降水量增加、温度下降.

The outgoing longwave radiation （OLR） of NOAA/AVHRR from satellite observations, the observed total cloud amount, precipitation and temperature data at 753 stations in China for the period 19892008 were used to investigate the relationships between the interannual variability of OLR over the Tibetan plateau （TP） in MayJune and JulyAugust and the climate over China in JulyAugust. The results show that the area averaged TP OLR reached 2 peaks in MayJune and SeptemberNovember respectively, and a relatively low value in JulyAugust. The areaaveraged TP OLR was lower during 19892002, and higher during 20032008. When the OLR over the TP decreased in MayJune, the total cloud amount and the precipitation increased and the temperature dropped over the southern China's Mainland, and a contrary situation occurred over the northern China and the southeastern coastland in JulyAugust. When the OLR over the TP decreased in JulyAugust, the total cloud amount and precipitation increased, and the temperature decreased over the southwestern parts of China in the same period.