SANCOR Seminar "Does air pollution fertilize the open ocean?" - Katje E Altieri
Speaker: Dr Katye E. Altieri, Energy Research Center, University of Cape Town
Topic: Does air pollution fertilize the open ocean?
Where and When: Monday, 8 February, 13:00. Oceanography Seminar Room
Abstract: Global models indicate that the human-derived nitrogen emissions that reach the ocean through atmospheric transport and deposition directly impact biology and the oceanic carbon dioxide (CO2) sink. Here, we find that the organic nitrogen in marine aerosols derives predominantly from biological production in the surface ocean rather than from pollution on land. Our previous work has hown significant anthropogenic influence on North Atlantic nitrate deposition whereas ammonium cycles dynamically between the upper ocean and lower atmosphere. Collectively, these findings indicate that the ocean is not a passive recipient of anthropogenic nitrogen deposition, as it has previously been considered. This implies that the contribution of atmospheric nitrogen deposition to ocean fertility, oceanic CO2 removal, and nitrous oxide emissions has been overestimated.