The source of unusually low surface salinities in the gulf stream off Georgia

Abstract

In September 1973, surface water salinities of the Gulf off Georgia were observed to be anomalously low. Salinity values of 35·5 to 36·4%0 are typical of thir area but values as low as 34.5%0 were observed. A conservative estimate of the onbserved volume flux of freshwater in the Gulf Stream was 1·2 km3 day−1. A possible source is runoff from the southeast United States; however, the total runoff flux is ca. 0·1 k;m3 day−1, which is not sufficient to supply the oberved flux. Therefore, it is hypothesized that the low water is of Mississippi River origin. This argument is further strengthened by observations of northern extension of the Gulf of Mexico Loop Current and Low salinity water is the Straits of Florida.