1996年北半球主要环流特征及其影响

１９９６年北半球主要环流特征是：５００ｈＰａ西太平洋副高偏弱，脊线位置初夏偏北，盛夏西端持续偏南；亚洲西风带后冬至初春经向环流明显发展，７月亚洲中纬度地区常有阻塞形势维持，５００ｈＰａ青藏高原位势高度偏高，夏季南支印缅槽较弱。

General Circulation and Its Impact over the Northern Hemisphere in 1996

General circulation features over the northeren hemisphere in 1996 were analysed.It is shown that the 500hPa subtropical high over the West Pacific was weaker than last year.Its ridge line moved northward in early summer and its west ridge line moved southward in midsummer.Meridional circulation was developed in early spring,blocking pattern was stable at middle latitude in midsummer.500hPa geopotential height was higher in Qingzang plateau,South westerly trough was weaker in summer.100hPa South Asia high in summer was stronger and moved eastward.Its ridge line moved southward.The La Nino was very weak and gone to normal in summer.