Sack Lunch Seminar (SLS)

Estimating the global-scale flow of energy through the marine planktonic food web

Abstract: Most global marine ecosystem models within earth system simulations emphasize the resolution of broad-scale carbon and nutrient dynamics. This often results in coarsely resolved planktonic food webs that limit the mechanistic resolution of biogeochemical processes and assessments of climate impacts on marine resources. The planktonic food web dynamics of the biogeochemical component of NOAA/GFDL’s earth system model have been enhanced to address these limitations. Global-scale ocean ice simulations with this model were assessed against observed and inferred patterns in the flow of energy through the planktonic food web, including primary production, bacterial production, microzooplankton grazing, the export of carbon from the euphotic zone, and mesozooplankton production. Diagnosis of model results provides global-scale estimates of the flow of energy through each component. Fluxes are further broken down by oceanic province and planktonic food webs within each structure are contrasted. Finally, we demonstrate that accounting for changes in planktonic food web structure across systems is critical for understanding global fisheries yields.