| Abstract: | Hydrographic data collected on monthly cruises over the West Louisiana and Texas shelf from 1963 to 1965 were analyzed and the volume of fresh water on the shelf was estimated for each data set. The freshwater volume exhibits an annual cycle that is dominated by the spring flood of the Mississippi and Atchafalaya rivers. During the winter, shelf freshwater content is low, with the highest content appearing as a discontinuous band along the inner shelf. In summer an isolated high-content region is present in the center of the shelf. This high-content region dissipates and the pattern migrates toward the southeast in the late summer. By late fall the winter distribution is again present.A fill time for the freshwater volume on the shelf was also estimated for each cruise. The freshwater volume appears, in most cases, to have originated near the time of the previous spring flood.Two of the study years had river discharges well below the long-term mean, while the third-year discharge approximated the long-term mean. These results, then, may not be applicable to large-discharge years. |
