应用SODA-1.4.2版本资料,分析研究了热带西太平洋暖池(以下简称WPWP)海温场的变化特征,讨论了WPWP海温的时空变化特征与ENSO之间的联系途径。分析结果表明,在上层海洋,WPWP的海温场在垂向结构上具有显著的年际变化特征,在不同深度存在较大差异。表层的异常海温出现明显的增温趋势,在47年期间(1958--2004)增温幅度达0.15℃。而随着深度的增加,异常海温出现明显的降低趋势,次表层(120—170m)的降温幅度最大,其降温可达-0.72℃。这种变化可能与20世纪70年代末WPWP区域的海温场发生突变过程存在一定关系。另外,在热带太平洋温跃层曲面上,WPWP区域海温变化与赤道东太平洋海温变化存在“跷跷板”现象。据此,定义了赤道东西太平洋温跃层曲面上异常海温变化强度指数,为ENSO循环过程的研究提供了又一参考依据。通过对WPWP不同深度的异常海温和海流分析发现,WPWP异常海温的东传过程与赤道潜流的强弱变化存在密切关系。
Based on the Simple Ocean Data Assimilation (SODA_1.4.2) dataset, the variability in ocean temperature in the West Pacific Warm Pool (WPWP) was analyzed. The spatial and temporal variation in ocean temperature in WPWP and its relationship with the ENSO cycle were discussed. The results indicate that the vertical inter-annual variability in ocean temperature in WPWP was notable, and the temperature varied greatly in different water depths. Surface temperature of the ocean increased abnormally by 0.15℃ in 47 years (1958--2004). However, the abnormal temperature reduced with the increase of depth. The maximal temperature decrease by -0.72℃was found in the subsurface(120--170m). Perhaps this variability was somehow related with the abrupt change in marine tem- perature in the end of 1970s. In addition, on the thermocline curved surface in tropical Pacific, a "seesaw" phenomenon between the abnormal sea temperature in WPWP and in east equatorial Pacific has been observed. Therefore, an index to the equatorial Pacific sea temperature oscillation (EPOI) was defined to describe the phenomenon, and should help study the ENSO cycle. Analyses on the vari- ability of anomalous ocean temperature and current in different depths in the equatorial Pacific have found that the eastward propagation of the anomalous sea temperature in WPWP was closely related with the variability of the equatorial undercurrent.