Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Biogeosciences, 10, 7219-7234, 2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
12 Nov 2013
Modeling ocean circulation and biogeochemical variability in the Gulf of Mexico
Z. Xue1, R. He1, K. Fennel2, W.-J. Cai3, S. Lohrenz4, and C. Hopkinson5 1Dept. of Marine, Earth & Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA
2Dept. of Oceanography, Dalhousie University, Halifax, Canada
3School of Marine Science and Policy, University of Delaware, Newark, DE 19716, USA
4School for Marine Science and Technology, University of Massachusetts Dartmouth, New Bedford, MA 02747, USA
5Dept. of Marine Sciences, University of Georgia, Athens, GA 30602, USA
Abstract. A three-dimensional coupled physical-biogeochemical model is applied to simulate and examine temporal and spatial variability of circulation and biogeochemical cycling in the Gulf of Mexico (GoM). The model is driven by realistic atmospheric forcing, open boundary conditions from a data assimilative global ocean circulation model, and observed freshwater and terrestrial nitrogen input from major rivers. A 7 yr model hindcast (2004–2010) was performed, and validated against satellite observed sea surface height, surface chlorophyll, and in situ observations including coastal sea level, ocean temperature, salinity, and dissolved inorganic nitrogen (DIN) concentration. The model hindcast revealed clear seasonality in DIN, phytoplankton and zooplankton distributions in the GoM. An empirical orthogonal function analysis indicated a phase-locked pattern among DIN, phytoplankton and zooplankton concentrations. The GoM shelf nitrogen budget was also quantified, revealing that on an annual basis the DIN input is largely balanced by the removal through denitrification (an equivalent of ~ 80% of DIN input) and offshore exports to the deep ocean (an equivalent of ~ 17% of DIN input).

Citation: Xue, Z., He, R., Fennel, K., Cai, W.-J., Lohrenz, S., and Hopkinson, C.: Modeling ocean circulation and biogeochemical variability in the Gulf of Mexico, Biogeosciences, 10, 7219-7234,, 2013.
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