Victoria Coles, Univ. of Maryland
Tracers have been used to validate ocean models as well as for estimating ventilation rates and timescales for decades. Now, biogeochemical tracers are of interest for their influence on climate. Here, we couple an ecosystem model to HYCOM in the Atlantic ocean. The ecosystem is very sensitive to modest biases in mixed layer depth due to the exponential decay of light in the upper ocean. The ecosystem is also very sensitive to the exchange of nutrients across the mixed layer base. As a result, the SeaWiFs ocean color data coupled with the ecosystem model reveal subtle variability in the interaction of the mixed layer with the deeper ocean. Different mixed layer models in HYCOM are tested with the basin scale biomass as a large scale indicator of the ability of the models to accurately simulate the seasonal cycle.