近百年全球温度变化中的ENSO分量

首先利用Nin~o C区海温、Nin~o 3区海温及两个不同的SOI序列,建立了1867年春到1998年春期间的ENSO指数序列。近百年来ENSO对热带、热带外地区年际尺度的温度变化有显著影响,热带地区温度变化滞后ENSO约1个季,热带外地区滞后约2～3个季。ENSO能解释同期全球年平均温度方差的14%～16%左右;如果考虑ENSO对温度影响的滞后特征,则能解释的部分提高到20.6%。ENSO对温度的影响主要是在年际时间尺度上,对近百年来全球温度变化的长期趋势和年代际变率贡献不大。

THE INFLUENCE OF ENSO ON GLOBAL TEMPERATURE DURING THE LAST 100 YEARS

 To explore the coupling between the atmosphere and the ocean in ENSO events, the combination of 2 SST indices and 2 SOIs back to the 1867 are used to define the ENSO index. The 2 SSTs are SST of Nin~o C(i.e. 180°～90°W,0°～5°S, Angell,1981) and SST of Nin~o 3(i.e. 160°E～90°W,5°N～5°S,Caneet al,1997), 2 SOIs are SOI of Ropelewski and Jones and SOI of Shi and Wang respectively.Then 32“warm phase”ENSO events and 32“cold phase”ENSO events are identified from the spring of
1867 to the spring of 1998. Then global temperature anomalies associated with ENSO are investigated by using long-period global gridded temperature records from 1880 to 1997. The influence of ENSO on both tropical and extra-tropical temperature are significant in annual time scale. The temperature lags ENSO by one season in tropic, and by two～three seasons in extra-tropics. ENSO can account for about 20.6% global interannual temperature variance. But ENSO can not explain the warming trend and the interdecadal variability of global temperature over the past century.