Friedrichs1, Marjorie A. M., Jerry D. Wiggert2, Raleigh R. Hood3, Ragu Murtugudde2, Julian P. McCreary4, Robert A. Armstrong5, Fei Chai6, James Christian7, John Dunne8, Scott Doney9, Katja Fennel10, Eileen E. Hofmann1, John M. Klinck1, Dennis J. McGillicuddy9, J. Keith Moore11, Yvette Spitz12, Kevin Arrigo13 and David M. Glover9

1Center for Coastal Physical Oceanography, Old Dominion University, Norfolk, VA 23529, Tel: 757-683-5560, Fax: 757-683-5550, E-mail: marjy@ccpo.odu.edu, 2ESSIC, University of Maryland, College Park, MD 20742, 3University of Maryland Center for Environmental Science, Cambridge, MD 21613, 4International Pacific Research Center, University of Hawaii, Honolulu, HI 96822, 5Marine Sciences Research Center, SUNY, Stony Brook, NY 11794, 6School of Marine Sciences, University of Maine, Orono, ME 04469, 8Princeton University, AOS Program, Princeton, NJ 08544, 9Woods Hole Oceanographic Institution, Woods Hole, MA 02543, 10Rutgers, The State University of New Jersey, IMCS, New Brunswick, NJ 08901, 11Earth System Science, University of California, Irvine, Irvine, CA 92697, 12COAS, Oregon State University, Corvallis, OR 97331, 13Stanford University, Department of Geophysics, Stanford, CA 94305

 

The Regional Ecosystem Modeling Testbed Project

 

An important legacy of the U.S. JGOFS Synthesis and Modeling Project will be the formulation of a broad suite of models designed to simulate biogeochemical cycling in the various process study regions. Although these modeling studies have already substantially advanced our understanding of these systems, few quantitative intercomparisons of these models have been made. As part of the Regional Ecosystem Modeling Testbed Project we are conducting these intercomparisons, in order to critically examine which ecosystem structures and formulations are most robust, and explore the reasons for their success. In order to facilitate these intercomparisons we are developing a set of regional testbeds, containing one-dimensional physical forcing fields and biogeochemical data. By running various ecosystem models using the same physical forcing, and evaluating them using the same data, we objectively compare different ecosystem models and modeling approaches. 

 

Work to date has focused on two regions: the equatorial Pacific (140W) and the Arabian Sea (15.5N, 61.5E); plans for other regions including the Southern Ocean, BATS, and HOT are currently underway. A prototype testbed in the Arabian Sea has been used to compare assimilative versions of three distinct ecosystem models. Results highlight the importance of the physical forcing fields (vertical velocity and mixed layer depth) and suggest that the additional complexity of multiple size class models may not always be justified. A Regional Testbed Workshop (March 2003) provided a venue for JGOFS investigators to use these testbeds to compare ecosystem model simulations. Results from this ecosystem model comparison will be presented.