Mesoscale variability in the Gulf of Mexico and its impact on the marine ecosystem

Physical and Biogeochemical dynamics at the Gulf of Mexico are influenced by the Mississippi river discharge. The Mississippi river is the largest river in United States and is annual discharge is around 16.200 m3/s. The biogeochemical impact of the Mississippi plume and its importance relative to upwelling and advection in supplying nutrients to the Gulf of Mexico is our research goal. With an interdisciplinary project will try to answer how the physical and biogeochemical process are linked, how the marine ecosystem responds to rapidly runoff changes and climate forcing, and in which way the anthropogenic and natural variability in the Mississippi basin are linked with the biogeochemical cycles in the Gulf of Mexico. We use the Regional Ocean Modeling System (ROMS) to investigate the feedbacks between circulation in the Gulf of Mexico, the Mississippi runoff and biological responses with a 5 km horizontal resolution grid and 30 vertical levels. The model has been initialized using temperature, salinity, horizontal velocities, sea surface high and fluxes from Simple Ocean Data Assimilation (SODA) reanalysis, and it is forced by mean monthly and daily winds from the microwave scatterometer sea winds QuikScat, over the period 2000 and 2008. A significant field program will complement the modeling effort model providing shipboard measurements and to be validated by the model.