1993年北半球环流特征及其对我国天气气候的影响

１９９３年北半球主要环流特征表现为：５００ｈＰａ副产持续加强西伸，位置偏南；亚洲中纬度春，夏经向环流发展，东亚太平洋遥相关型稳定；西藏高原５００ｈＰａ位势高度持续偏高，印缅槽持续偏弱；１００ｈＰａ位势高度场低纬持续偏高，中，高纬持续偏低，夏季南亚高压位置异常偏高。热带海洋出现明显异常，一次新的厄尔尼诺现象发生。热带海洋和北半球大气环流的异常对我国天气气候产生明显影响。

General Circulation over Northern Hemisphere in 1993 and Their Impact on the Weather and Climate in China

General circulation features over the Northern Hemisphere in 1993 are analysed. It is shown that the subtropical high over the west Pacific is stronger than normal,and extends to the,west,and at the same time moves southward continuosly.Meridinal circulation is dominant in the middle latitude of Asia in the spring and summer.The East Asia/Pacific teleconnection pattern is very stable.At 500hPa,the geopotential height over the Qinghai-Xizang plateau is higher than normal since March.The southern branch trough is weaker than normal. At 100hPa,the geopotential height in the low latitude is above normal, but that in the middle-high latitude is below normal.The location of the South Asia High is farther to the south than normal. A new El Nino event took place in the tropical Pacific in 1993. The anomaly of both the tropical Pacific and atmosphere circulation exerted a significant impact on the weather and climate in China.