1980～1999年热带太平洋次表层盐度年际变化同化数据分析

Interannual variations of sub-surface salinity in the tropical Pacific Ocean

通过统计方法利用一套海洋同化数据分析了热带太平洋次表层的盐度变化特征.结果表明次表层盐度的年际变化与ENSO相关,且次表层盐度信号区域呈东西方向“跷跷板”的分布.对影响这些次表层的盐度信号区域平均的纬向平流、经向平流、垂直运动和淡水通量异常等因素进行了分析,并且与影响表层盐度年际变化模态的影响因素差异进行了比较,结果表明,纬向平流的异常对表层盐度的异常变化影响较大,而对次表层盐度异常有较大影响的是海水的垂直运动异常.

The salinity variability on the interannual time-scale is analyzed using SODA data by EOF statistical method. The results show that there is high correlation coefficient between interannual variation in the sub-surface salinity and ENSO. The signatures have a pan-longitudinal ＂seesaw＂ feature. The factors including zonal advection, meridional advection, vertical movement and fresh water flux anomalies were analyzed. The difference among these factors, which play important roles for surface and sub-surface salinity variations, was investigated. It was shown that the zonal advection anomaly is a more important factor in the surface but the vertical movement anomaly for the sub-surface regarding salinity variability on the interannual time-scale.