A new method to transform satellite ocean color data into estimates of primary production and carbon fluxes is presented. A one-dimensional coupled physical-bio-geochemical model of the surface ocean is constrained to reproduce the seasonal evolution of surface chlorophyll concentration by adjusting the parameters of the 10-compartment trophic system using a variational technique. The method is applied to in situ surface chlorophyll data from station Papa. Using 35 measurements for the year 1976, it is found that five linear combinations of the trophic parameters can be adjusted.