Mississippi river plume variability in the gulf of Mexico based on modis-aqua and smap observations

The Mississippi River is an important source of freshwater and of terrigenous material to the Gulf of Mexico (GoM). This study aims to describe the Mississippi River Plume (MRP) seasonality and its interaction with the GoM circulation. We used terrigenous dissolved organic carbon from MODIS-Aqua and sea surface salinity from Soil Moisture Active Passive (SMAP) satellite to trace the distribution of the river plume in the coastal ocean. For the first time, the frequency of plume occurrence in the Gulf of Mexico was quantified. The MRP distribution on monthly time scales is controlled primarily by river discharge and by alongshore winds, with the maximum plume extension occurring during summer due to frequent reversions in winds. Two anomalous events in 2015 and 2016 demonstrated the importance of the interplay between upwelling-favorable winds, peaks in river discharge, the Loop Current and associated eddies on the offshore transport of MRP waters.