U.S. Environmental Protection Agency
EPA Science Advisory Board
Background Information

Document NameStorm-induced injection of the Mississippi River plume into the open Gulf of Mexico.
Document AuthorYuan, J.C.
Miller, R.L.
Powell, R.T.
Dagg, M.J.
Short DescriptionGeophysical Research Letters 31 (9): Art. No. L09312.
CategorySubgroup 1: Characterization of the Cause(s) of Hypoxia
Publication Year2004

Abstract: The direct impact of the Mississippi River on the open Gulf of Mexico is typically considered to be limited due to the predominantly along-shore current pattern. Using satellite imagery, we analyzed chl a distributions in the northern Gulf of Mexico before and after the passage of two storms: Hurricane Lili and Tropical Storm Barry. Our analyses indicate that storm-induced eddies can rapidly inject large volumes of nutrient-rich Mississippi River water to the open gulf, and lead to phytoplankton blooms. Although these events last only a few weeks, they transport significant amounts of fluvial substances to the ocean. These river-ocean interactions are especially significant in tropical and subtropical regions because receiving waters are typically permanently stratified and oligotrophic.