CAJ | 학술논문

利用英国气象局哈得来中心的1950-2011年月平均海表温度资料，采用联合回归-经验正交函数分解方法得到东部太平洋型ENSO（东部型ENSO）和中部太平洋型ENSO（中部型ENSO）的热带太平洋海温分布特点，进而定义了计算相对简单的东部型ENSO指数（IEP ）和中部型ENSO指数（ICP ）来分别描述两类ENSO。研究结果表明：首先，构建的IEP和ICP的相关性很小，接近正交，而且IEP和ICP能够反映两类ENSO 不一致的偏度和周期，因此，这对指数能够清楚地区分两类 ENSO。其次，IEP和ICP这两个指数可以描述厄尔尼诺和拉尼娜事件成熟期主要海表温度异常区的位置。再次，应用IEP和ICP从随机事件概率统计的角度给出两类厄尔尼诺和拉尼娜事件较为严格的定义，以便实时有效地监测两类ENSO。最后，利用新指数对两类ENSO的特征进行研究发现，强厄尔尼诺事件一般属于东部型，而强拉尼娜事件则为中部型，并且中部型拉尼娜事件发生的前期是东部型厄尔尼诺，此外，ENSO的发生演变机制在1976/1977年前后发生了改变。
이용영국기상국합득래중심적1950-2011년월평균해표온도자료，채용연합회귀-경험정교함수분해방법득도동부태평양형ENSO（동부형ENSO）화중부태평양형ENSO（중부형ENSO）적열대태평양해온분포특점，진이정의료계산상대간단적동부형ENSO지수（IEP ）화중부형ENSO지수（ICP ）래분별묘술량류ENSO。연구결과표명：수선，구건적IEP화ICP적상관성흔소，접근정교，이차IEP화ICP능구반영량류ENSO 불일치적편도화주기，인차，저대지수능구청초지구분량류 ENSO。기차，IEP화ICP저량개지수가이묘술액이니낙화랍니나사건성숙기주요해표온도이상구적위치。재차，응용IEP화ICP종수궤사건개솔통계적각도급출량류액이니낙화랍니나사건교위엄격적정의，이편실시유효지감측량류ENSO。최후，이용신지수대량류ENSO적특정진행연구발현，강액이니낙사건일반속우동부형，이강랍니나사건칙위중부형，병차중부형랍니나사건발생적전기시동부형액이니낙，차외，ENSO적발생연변궤제재1976/1977년전후발생료개변。
Taking into account the different equatorial Pacific sea surface temperature (SST)patterns obtained from a combined EOF-regression analysis for the Eastern Pacific type of ENSO (EP-ENSO)and the Centre Pacific type of ENSO (CP-ENSO), this study constructs IEP (EP-ENSO Index)and ICP (CP-ENSO Index)for the two types of ENSO.The analysis is performed for the period of 1950-2011 using the monthly mean Met Office Hadley Centre SST analyses data.Some conclusions are as follows.Firstly,the two indices are nearly orthogonal and the skewness coefficients for IEP and ICP are 1.56 and -0.43,re-spectively.In addition,EP-ENSO and CP-ENSO show different periods.The former has two dominant periods,one is near the 2 year band and the other is near the 4-8 year band.The latter has two significant powers around the 2-4 year and 12 year band from 1965 to 1995.Therefore,low correlation,different leading periodicity and skewness are all desirable properties for the above defined indices to separate the EP and CP type of ENSO.Secondly,IEP and ICP indices can describe the location of SST anomalies in the mature period of the two types of El Ni~no and La Ni~na events.Thirdly,from the perspective of probabili-ty and statistics of random events,two types of El Ni~no and La Ni~na events are more strictly defined by using this pair of new indices,which could be applied to monitoring the two types of ENSO effectively and in real-time.Finally,the two new indices can also depict characteristics of the equatorial Pacific SST zonal propagation and evolution during ENSO events,their running lagged correlations capture different ENSO phase propagations and ENSO regime changes associated with the climate shift in 1976/1977.It is also noticed that most strong El Ni~no events belong to the EP type,but most strong La Ni~na events are to the CP type,and CP type of La Ni~na events tend to occur after the EP type of El Ni~no events.