500hPa高度场上两极和赤道位势高度气候演变规律的研究

Investigation on evolutive law of geopotential height of two poles and the equator at 500hPa geopotential height field

本文运用近50 a来500 hPa层次上南极、赤道和北极位势高度以及南北半球西风指数的资料,分析了它们的时间演变规律及其相互间的关系.结果表明,南极位势高度显著下降;赤道位势高度显著上升.南极、赤道和北极位势高度都存在着显著的年际、年代际变化特征.总体上,南极位势高度与赤道位势高度有极其显著的负相关关系,北极与赤道的位势高度之间以及两极位势高度之间相关关系不显著;在共振的特定频率中,北极位势高度振荡落后于南极位势高度,赤道位势高度振荡又落后于两极位势高度振荡,气候变化最先开始的区域为南极地区.进一步分析表明,伴随着以上三个区域的位势高度趋势变化及其周期振荡,必然引起高空西风的增强与周期振荡.研究表明,南北两半球西风指数都存在显著的上升趋势,且存在显著的年代际变化特征.其中,南半球西风指数上升幅度较北半球大,其振荡落后于南极位势高度.

Analysing the geopotential height data of the South Pole, the Equator, the North Pole and zonal wind at 500 hPa level, we can find their evolutive law and the correlation between one and another. We conclude that Antarctic geopotential height descends and tropic geopotential height ascends and the trend of Arctic geopotential height change is not visible. There are obvious chronological and interannual changes at South Pole, Equator and North Pole. Geopotential height represents anticorrelation between the Antarctic pole region and tropic region. There is no significant correlation between the Arctic pole region and tropic region, so as correlation between Antarctic region and Arctic region. In the process of change, North Pole vibrates after South Pole, tropic region vibrates after pole region, the first change region is the South Pole. Zonal wind at middle and high latitudes ascends significantly and changes chronologically and interannually, zonal wind in the south hemisphere vibrates after geopotential height at the Antarctic region.