热带有关海域海表温度、南方涛动和我国东部气温的谱分析

SPECTRUM ANALYSIS OF TRCPICAL SST SOUTHERN OSCILLATION AND EASTERN CHINA TEMPERATURE

本文采用波谱分析法对热带有关海域海表温度、南方涛动指数和我国东部气温作了分析。通过功率谱计算表明:(1)南海、赤道西太平洋和印度洋月海表温度变北分别存在3.4、6.8和1.4年振动周期。(2)我国华北、长江中、下游及华南地区月气温变化分别存在1.1、3.4和3.4年振动周期。交叉谱分析表明:在3.4年周期振动上,南方涛动依次超前南海月海表温度、长江中、下游及华南地区月气温变化;南海月海表温度依次超前于华南月气温及赤道东太平洋海表温度变化,这在某种意义上可把南海水温低频振动作为厄·尼诺监测器是有价值的。本文还对我国东部气温年际变化与厄·尼诺现象作了简单分析。

The relevant tropical SST, southern oscillation index and East-China's temperature are analyzed in terms of a wave spectrum technique. The power spec 1 rum analyses indicate: i) monthly mean SSToscillatioris w i f h 3.4, 6.8 and 1.4-year periods for the South-China Sea, western equatorial Pacific and the Indian, respec lively; and ii) 1.1, 3.4 and 3.4-year periods for the northern part, mid/lower Chang-Jiang reaches and the southern part of the country, respectnely. Cross spectrum analyses show that for the 3.4-year periods the occurrence of southern oscillat ion precedes variation in SST of the South-China Sea, and temperature over the mid /lower Changj iang reaches and southern China on a monthly mean basis. The SST of the Sea changes ahead of south China and the eastern equatorial Pacific on the same basis, leading to the fact that, in a sense, it is of value to view the low-frequ-ency oscillation of the South China Sea SST as the monitor of an El Nino event. Further, relationship is analyzed between the annual variation in eastern China's temperature and El Nino occurrence.