Argo observations revealed dramatic sea surface salinity (SSS) changes in the northeastern tropical Pacific Ocean (NETPO) during the past one and half decades, with a steady increase during 2004–2012 and a sharp decrease during 2013–2016. These changes mainly result from anomalous precipitation associated with the Walker Circulation through moisture transport across Central America. The anomalous Walker Circulation is caused by changes in trans-basin sea surface temperature (SST) gradients, especially those in the eastern tropical Pacific. Results using a longer reanalysis indicate that the upward trend of SSS in the NETPO started from the mid-1990s as the moisture transport across Central America decreased in response to reduced trans-basin SST gradients associated with the Interdecadal Pacific Oscillation and Atlantic Multidecadal Oscillation.

Argo观测显示，过去十五年间，东北热带太平洋（NETPO）的海表盐度（SSS）发生了显着变化，2004-2012年期间稳定增加，2013-2016年期间急剧减少。这些变化主要是由于通过中美洲的水汽输送与沃克环流有关的异常降水所致。沃克环流异常是由跨盆地海表温度（SST）梯度的变化引起的，特别是在东部热带太平洋地区。使用较长时间的重新分析结果表明，NETPO中SSS的上升趋势始于1990年代中期，这是由于随着年代际太平洋涛动和大西洋多年代际涛动相关的跨盆地SST梯度减小，整个中美洲的水分输送减少了。