Surface Salinity Variability in the Gulf of Mexico During Flood and Drought Years

Abstract

The interaction between the Loop Current System (LCS) and the Gulf of Mexico (GoM)'s freshwater circulation is investigated during flood and drought years. We combine satellite-derived sea surface salinity (SSS), ocean currents, and river discharge rates to examine patterns of salinity distribution throughout the entire GoM basin. Saline waters were reported intruding up the Mississippi River during drought years, so a close examination of these years is conducted. The relationship between the Loop Current (LC) and freshwater distribution are further investigated using a stepwise linear regression model. The relative impacts of river discharge and surface advective freshwater fluxes are quantified, and it is concluded that basin-wide SSS depends significantly on the discharge from the Atchafalaya River, which leads by 4 months. Interannual salinity variability in the GoM is found to depend on the combination of discharge magnitude and timing relative to the position of the LCS.