Associated Nitrate and Physical Variability in the Mississippi Bight at the CenGOOS Mooring USM3m01

An ocean observing buoy, deployed in the Mississippi Bight at (30 02 32.7N, 088 38 50.2W) in mid December 2004, has been measuring meteorological and oceanographic parameters and telemetering that data back to the USM Department of Marine Science in near real-time. The buoy is an initial element in the Central Gulf of Mexico Ocean Observing System (CenGOOS). Half-hourly data from that buoy are available every three hours at the CenGOOS website: www.cengoos.org. The 3-m discus buoy has a meteorological package measuring air pressure, vector winds, and air temperature and humidity. On the yoke beneath the hull are mounted a SeaBird Microcat, an Aanderaa DCS 3900R current meter, an RDI Workhorse 600 kHz ADCP, and a Satlantic ISUS nitrate sensor. The data from the buoy are providing a unique time series of nitrate variability at the site in conjunction with the local atmospheric forcing, and near surface ocean temperature, salinity, and current variability. Ocean color images, when available, help to put the variability at this site into a broader context. An overview of the results, along with more detailed analyses of a few events will be presented. For example, variations in salinity at the buoy site appear to be correlated linearly with variations in ambient nitrate concentrations. This trend enables us to relate variations in water quality parameters (e.g., nitrate concentrations) to specific external forcing and meteorological events (e.g., passing of fronts and plumes).