西北太平洋热状况与夏季副高脊线变异

用1951～1986年亚洲太平洋地区500hpa月平均高度、西北太平洋月平均海表温度及夏季500hpa副高脊线位置资料,分析海温对夏季副高脊线年际变异的影响。得出结论:(1)1～8月海温距平EOF1～3场对夏季副高脊线变异具有明显影响的共有9个。(2)夏季各月副高脊线年际变化都具有明显的主周期。而且它们是由同期海温距平EOF2场所引起。(3)夏季各月副高脊线变异可能是由同期海温距平EOF2场的东西向“热成风效应”过程所致。

RALATIONSHIP BETWEEN THE SUBTROPICAL HIGH IN SUMMER AND THE THERMAL REGIME ANOMALY IN THE NORTHWEST PACIFIC

In this paper,the effect of the sea surface temperature (SST) on the intcrannual variation of the ridge line position of the Western Pacific Subtropical High is analysed by using the data of the monthly 500hpa geopotcntial height,the monthly SST and the position of the 500hpa Subtropical High in the Northwest Pacific in the Summers from 1951 to 1986 The results are as follows: (1) From the modes 1-3 of the empirical orthogonal function(EOF) of SST in each month from January to August,there are 9 patterns that correlated closely to the variations of the ridge line position of the Western Pacific Subtropical High.(2) In each of the summer months,the interannual variation of the ridge line position of the Subtropical High is characterized by obvious periodicity;furthermore,it is linked to the second mode of the SST in the same period.(3) The variations of the Subtropical ridge line are probably caused by "the effect of the zonal thermal wind" of the second mode of the SST in the corresponding period.