南北半球副热带高压对赤道东太平洋海温变化的响应

本文利用1974年1月到1996年12月重分析(NOAANCEP-NCARCDAS-1)全球500hPa位势高度场资料,及同期赤道太平洋各海区SST资料,研究了南北半球副热带高压的变化特征及其对赤道东太平洋SST变化的响应。结果表明,全球副热带高压的变化及对SST的响应,在南北两个半球有很好的一致性。全球副热带高压强度的变化与超前3个月SST的正相关最为显着。对SST响应最强烈的区域主要在南北纬30°之间的低纬,低纬地区局地SST对副热带高压也有强烈的影响。从10°到30°纬度,对SST的响应分别落后于赤道2～9个月。在中、高纬大气环流的响应表现为波列特征,对暖SST及冷SST的响应波列基本相反,但对暖SST的响应更为显着。海温和副热带高压的月际持续性有明显的季节变化,副热带高压9-10月的相关障碍可能与NinoC区SST8-9月的相关障碍低点有关。

Response of global subtropical highs to the equatorial eastern Pacific SST anomaly

Based on the reanalysis data of global 500 hPa geopotential height (NCEP-NCAR CDAS-1) and tropical Pacific SSTs, the characteristics of the global subtropical highs and their response to tropical eastern Pacific SST are investigated. Results show that the global subtropical highs respond to SST consistently. Subtropical high intensity correlates to the 3 months leading SST maximally. The relationships between SST and 500 hPa height stand out in low latitudes. The time for 500 hPa height reaching maximum correlation to SST is 2 months later in latitude of 100 and 9 months in latitude of 300 than equatorial zone. And the response of atmospheric circulation over extratropic performs as wave train, and the response is more significant in the condition of warmer SST. Persistence of SSTs and subtropical highs change obviously from season to season. Minimum persistence of subtrbpical highs in September and October may relate to the low persistence of SSTs in August and September.