[A-CG46] Biogeochemical linkages between the surface ocean and atmosphere

[ACG46-01] Evaluation of anthropogenic iron dissolution model using aerosol iron solubility over the Bay of Bengal

*Akinori Ito¹, Clarissa Baldo², Zongbo Shi² (1.Japan Agency for Marine-Earth Science and Technology, 2.University of Birmingham)

Keywords:anthropogenic iron, aerosol chemical transport model, laboratory experiment

Mineral dust is the largest source of aerosol iron (Fe) to the open ocean. In contrast, acidic dissolution processing of anthropogenic Fe leads to high Fe solubility and thus can result in a much higher contribution of dissolved Fe cycle in the surface ocean. In this presentation, we evaluate the process of combustion-derived aerosol Fe dissolution scheme, which was developed based on our laboratory experiments, in an aerosol chemical transport model, using aerosol Fe solubility over the Bay of Bengal.
Our laboratory experiments showed a much faster iron dissolution rate of combustion aerosols than mineral dust. The aerosol chemical transport model was used to evaluate the Fe dissolution schemes using the aerosol Fe solubility over the Bay of Bengal. The results showed that the improved model better reproduced the observed data by considering the initial rapid release of Fe and the suppression effect of oxalate on the proton-promoted Fe dissolution rate. On the other hand, by considering only the proton-promoted Fe dissolution rate, the model overestimated the observed data. Further, the results are discussed in terms of future research needed to predict the effect of anthropogenic aerosols on ocean fertilization more accurately.