Global River Discharge Variability Revealed by Aquarius and SMOS Sea Surface Salinity

Abstract:

Sea surface salinity (SSS) is an effective indicator of global freshwater cycle. At the mixed layer, salinity is governed by the net freshwater flux from ocean evaporation (E), precipitation (P), and continental discharge (Q), horizontal advection, and vertical mixing. Here, we use new SSS observations from Aquarius/SAC-D and SMOS, complimented by in situ observations from Argo floats, multiple satellite-based datasets for E and P, and modeled datasets to detect, isolate, and analyze the spatial and temporal patterns of discharge plumes from major rivers in the world. We perform harmonic and EOF analyses to reveal the dominant modes, amplitudes, and frequencies to estimate the fraction of sea surface salinity variability as explained by river discharge at global as well as regional scale.