2003年北半球大气环流及中国气候异常特征

2002年发生的厄尔尼诺事件于2003年初结束；受这次事件的影响，西太平洋副热带高压冬、春、夏、秋季持续偏强；夏季西伸脊点位置偏西；6、7月脊线位置偏南，8月偏北。初夏6月上中旬有贝加尔湖阻高影响，6月下旬至7月中旬有鄂霍次克海阻高影响；盛夏东亚夏季风异常偏强；青藏高原500hPa高度年趋势偏高，大部分地区冬季积雪少；热带对流强度年趋势偏弱。

General Circulation over the Northern Hemisphere in 2003 and Its Impact on the Climate in China

General Circulation features over the Northern Hemisphere in 2003 are analyzed. It's shown that the subtropical high at 500hPa over the western Pacific in the winter of 2002/2003 and the spring and the summer and the autumn of 2003 was stronger than normal.The 500hPa geopotential height anomaly was positive for most of the cases over the Northern Hemisphere in 2003. Both in the summer and autumn,the 500hPa geopotential height anomaly of Tibetan Plateau was positive. The East Asian monsoon was stronger than normal in July and August.The equatorial convergence zone was not more active than nomal.The SSTa in the eastern tropical Pacific was nomal in 2003. The results show that the anomalies of both the tropical Pacific sea temperature and atmospheric circulation would exert a significant impact on the weather and climate in China.