Consistency of Aquarius sea surface salinity with Argo products on various spatial and temporal scales

Abstract

AbstractUnderstanding the accuracies of satellite‐derived sea surface salinity measurements in depicting temporal changes and their dependence on spatiotemporal scales is important to applications, capability assessment, and future satellite mission design. This study quantifies the consistency between Aquarius Version 4 monthly gridded sea surface salinity (SSS) with two Argo‐based monthly gridded near‐surface salinity products for describing temporal changes on 1° × 1°, 3° × 3°, and 10° × 10° scales. Globally averaged standard deviation values for Aquarius‐Argo salinity differences on these three spatial scales are 0.16, 0.14, and 0.09 practical salinity unit (psu), compared to those between the two Argo products of 0.10, 0.09, and 0.04 psu. The consistency between Aquarius and Argo is similar to that between the two Argo products in the tropics for seasonal signals, and in the tropics and midlatitudes for nonseasonal signals. Therefore, the uncertainties of Argo products for various scales need to be considered in evaluating satellite SSS. Innovative satellite technologies are needed to improve high‐latitude satellite SSS measurements.