摘要
基于SODA再分析资料以及SST、JEDAC和TAO观测资料,利用加权平均法建立了具有良好代表性的暖池整体暖水的纬向运移指标序列,并利用Morlet小波变换等分析方法,研究了暖池的纬向变异特征及其对ENSO的影响。结果表明,暖池具有明显的年际(2—7年)和年代际(10—16年)纬向变异,并在1976年前后经历了一次由弱到强的气候跃变。暖池内部的暖水大致可以50m为界分为上、下两部分,其上半部分的纬向变异幅度非常大,而其下半部分的纬向变异幅度则相对较小。但两者具有很一致的年际、年代际变化趋势。暖池的年代际纬向变异对赤道中太平洋纬向风应力和纬向流有较好的响应,而且对赤道西太平洋上层热含量变化有较大影响。相关和合成分析表明,暖池的东扩、西缩对ENSO暖(El Nio)、冷(La Nia)事件的形成和发展具有直接的影响,而且暖池的异常东扩对El Nio有增强作用。
Based on the SODA data, SST data, JEDAC data, and TAO data, an index for zonal displacement of the Western Pacific warm pool （WPWP） is introduced using weighted-mean method in this study. The variability of WPWP zonal displacement is analyzed using the Morlet wavelet transformation method, and the effect of WPWP zonal migration on ENSO is discussed using composite and correlation analyses. The results show that the eastern edge of the warm pool is of most striking interannual （2-7a） and interdecadal （10-16a） changes, and experienced a weak/strong regime shift preand after-1976. As for WPWP zonal displacement, the whole warm pool can be divided spatially into two parts, i.e., upper and lower parts demarcated near 50m-depth. The extent of zonal displacement in upper warm pool is much more distinct than that in lower part, but the trends of interannual and interdecadal changes in them are largely identical. In interdecadal variation, WPWP zonal displacement responses well to the zonal current, and especially zonal wind stress, in the equatorial central Pacific, it has remarkable impact on the western equatorial Pacific heat content variation. The results of composite and correlation analyses reveal that WPWP zonal migration plays a direct role in the formation and development of ENSO. Furthermore, the eastward expansion of WPWP has the impact that enlarges the E1 Ni no events.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2008年第1期65-73,共9页
Oceanologia Et Limnologia Sinica
基金
国家自然科学重点基金项目，90411013号
卫星海洋环境动力学国家重点实验室(国家海洋局第二海洋研究所)开放研究基金项目，200601号
关键词
西太平洋
暖池
纬向变异
ENSO
Western Pacific Ocean, Warm pool, Zonal displacement, ENSO
