Hood, R. R. UMCES/HPL, raleigh@hpl.umces.edu
May, L. R. UMCES/HPL, may@hpl.umces.edu
Subramanium, A. UMCES/CBL, subraman@cbl.umces.edu
Carpenter, E. J. SUNY at Stony Brook, ed@imp.med.uni-muenchen.de
Capone, D. G. UMCES/CBL, capone@cbl.umces.edu

 
MODELING NITROGEN AND CARBON FIXATION OF TRICHODESMIUM: SHIPBOARD AND REMOTE SENSING APPLICATIONS
 
Biogeochemical modeling and mass balance calculations have recently indicated that N2 fixation is a more significant source of new nitrogen than previously thought and therefore can result in a greater sink for atmospheric CO2. Revised estimates of global marine N2 fixation rates by Trichodesmium and other pelagic diazotrophs corroborate this conclusion. We are currently working to develop a numerical model which can be used to estimate integrated N2 and carbon fixation rates from Trichodesmium biomass measured either from ship or from satellite ocean color sensors. This model, which is based upon a non-linear, three-parameter (Alpha, Pmax and Beta) light response curve, a vertically variable subsurface biomass distribution, and exponential decay of light in the water column, is parameterized using measured Trichodesmium N2 and carbon assimilation versus irradiance data, and observed near surface biomass profiles. Vertical integration is carried out numerically. The physiological and observational basis of this model will be discussed emphasizing observed variability in model parameters, relationships to environmental factors, and potential remote sensing applications.
 
Day: Tuesday, Feb. 2
Time: 09:00 - 09:15am
Location: Sweeney Center
 
Code: SS43TU0900S