Samantha Siedlecki
Graduate Student
E-mail: siedlesa at uchicago.edu
The fate of carbon dioxide is largely controlled by the chemistry of the ocean and its sediments. The coastal ocean only represents 8% of the global ocean, but the amount of carbon produced and buried there makes it an important part of the global carbon cycle. It contributes 18-33% to the production of the whole ocean and the rate of organic carbon fluxes to the seafloor, or benthic fluxes, exceed those in the open ocean by an order of magnitude. Approximately 90% of organic carbon burial occurs shallower than 1000m water depth. Currently, global circulation models (GCMs) have resolutions that are too coarse to involve these areas in their calculations. I am developing a parameterization of organic carbon export to the open ocean as a function of wind direction and shelf size in order to incorporate the coastal ocean into GCMs. That will allow questions to be answered about the global carbon cycle which could not be asked before. For example, the influence of sea level changes on the global carbon cycle. To accomplish this goal I am developing a dynamical model of a passive margin by adapting an existing model developed for open ocean fronts. I am also adding a biogeochemical model and designing several new tracers to better understand the mechanisms of exchange between the shelf and the open ocean.
