Using a gridded array for real-time geostrophic oceanography (Argo) program float dataset, the features of upper-ocean salinity stratification in the tropical Pacific Ocean are studied. The salinity component of the squared Brunt-Väisälä frequency N² (N ²_S ) is used to represent salinity stratification. Layer-max N ²_S (LMN), defined as the N ²_S maximum over the upper 300 m depth, and halocline depth (HD), defined as the depth where the N ²_S maximum is located, are used to specifically describe the intensity of salinity stratification. Salinity stratification in the Topical Pacific Ocean has both spatial and temporal variability. Over the western and eastern equatorial Pacific, the LMN has a large magnitude with a shallow HD, and both have completely opposite distributions outside of the equatorial region. An obvious seasonal cycle in the LMN occurs in the north side of eastern equatorial Pacific and freshwater flux forcing dominates the seasonal variations, followed by subsurface forcing. At the eastern edge of the western Pacific warm pool around the dateline, significant interannual variation of salinity stratification occurs and is closely related to the El Niño Southern Oscillation event. When an El Niño event occurs, the precipitation anomaly freshens sea surface and the thermocline shoaling induced by the westerly wind anomaly lifts salty water upward, together contribute to the positive salinity stratification anomaly over the eastern edge of the warm pool. The interannual variations in ocean stratification can slightly affect the propagation of first baroclinic gravity waves.

利用网格化的实时地转海洋学（Argo）程序浮点数据集，研究了热带太平洋上层海洋盐度分层的特征。平方的Brunt-Väisälä频率N ²（N ² _S）的盐度分量用于表示盐度分层。最大层N ² _S（LMN），定义为上部300 m深度上的N ² _S最大值，以及晕线深度（HD），定义为N ² _S所在的深度 最大值位于，用于具体描述盐度分层的强度。局部太平洋的盐度分层具有时空变异性。在赤道太平洋的东部和西部，LMN的大小很大，HD较浅，并且在赤道区域之外的分布都完全相反。LMN的一个明显的季节周期发生在赤道东太平洋的北侧，淡水通量强迫主导了季节变化，其次是地下强迫。在日期线周围的西太平洋暖池东缘，发生了盐度分层的年际变化，并且与厄尔尼诺南方涛动事件密切相关。当发生厄尔尼诺事件时，降水异常使海面变新，而西风异常引起的温跃层浅滩使咸水向上抬升，共同促进了暖池东缘的正盐度分层异常。海洋分层的年际变化会略微影响第一斜斜重力波的传播。