大气科学进展(英文版)
大氣科學進展(英文版)
대기과학진전(영문판)
ADVANCES IN ATMOSPHERIC SCIENCES
2010年
5期
1210-1220
,共11页
李根%任保华%杨成昀%郑建秋
李根%任保華%楊成昀%鄭建鞦
리근%임보화%양성윤%정건추
厄尔尼诺现象%IEMI%热带太平洋%EOF分析%海表温度异常%信号干扰%监测指标%权重系数
阨爾尼諾現象%IEMI%熱帶太平洋%EOF分析%海錶溫度異常%信號榦擾%鑑測指標%權重繫數
액이니낙현상%IEMI%열대태평양%EOF분석%해표온도이상%신호간우%감측지표%권중계수
El Nino%El Nino Modoki%NINO3 index%improved El Nino Modoki index (IEMI)
In recent years, El Nino Modoki (a type of pseudo-El Nino) has been distinguished as a unique large-scale ocean warming phenomenon happening in the central tropical Pacific that is quite different from the traditional El Nino. In this study, EOF analysis was used to successfully separate El Nino and El Nino Modoki. The abilities of the NINO3 index, NINO3.4 index, NINO1+2 index and NINO4 index in characterizing El Nino were explored in detail. The resulting suggestion was that, comparatively, NINO3 is the optimal index for monitoring El Nino among the four NINO indices, as the other NINO indices were found to be less good at distinguishing between El Nino and El Nino Modoki signals, or were easily disturbed by El Nino Modoki signals. Further, an improved El Nino Modoki index (IEMI) was introduced in the current paper to better represent the El Nino Modoki that is captured by the second leading EOF mode of monthly tropical Pacific sea surface temperature anomalies (SSTAs). The IEMI is an improvement of the El Nino Modoki index (EMI) through adjustments made to the inappropriate weight coefficients of the three boxes of EMI. The IEMI therefore overcomes the EMI’s inability to monitor the two historical El Nino Modoki events, as well as avoids the possible risk (present in the EMI) of excluding the interference of the El Nino signal. The realistic and potential advantages of the IEMI are clear.