We developed an improved parameterization of dynamic phytoplankton iron-to-carbon ratios (Fe:C) and examined the biogeochemical impacts and potential feedbacks to climate change in simulations with varying levels of atmospheric iron deposition.
Phytoplankton acclimate to low iron concentrations by reducing their iron quotas (Fe:C ratios). Accurately, accounting for this dynamic phytoplankton stoichiometry is critical to predict how the biological pump and marine carbon cycling will respond to climate change and varying atmospheric iron deposition.
Iron is the growth-limiting nutrient over > 33% of the oceans. Variable plankton Fe:C ratios link carbon export and the ocean’s biological pump to available iron. Fe:C variations strongly impact important nitrogen cycle fluxes and the response to varying atmospheric iron deposition.