Presentation Information
[ACG64-04]Model Evaluation of Iron-containing Aerosols from Anthropogenic and Lithogenic Sources Based on Observations
*Akinori Ito1, Minako Kurisu2, Kana Nagashima1 (1.Japan Agency for Marine-Earth Science and Technology, 2.The University of Tokyo)
Keywords:
water-soluble iron,anthropogenic aerosol,mineral dust,air pollution
Atmospheric depositions of bioaccessible iron (Fe) from anthropogenic (fuel combustion and metal production), lithogenic (wind-blown dust), and pyrogenic (open biomass burning and pyro-convective dust) aerosols represent important external sources of micronutrients to the open ocean, which could affect marine ecosystems and climate through marine biogeochemical feedbacks. However, significant uncertainties remain in the source apportionment, due to a lack of source-specific evaluation of Fe-laden aerosols. In this presentation, we evaluate the source contributions predicted by atmospheric chemistry transport model using aerosol and seawater filtration samples collected during research cruises in the North Pacific region. Particularly, we focus on trace metals (Fe, Al, Ti, V, Mn, Cu, Zn, Pb) and dust (quartz) in aerosols.
The IMPACT model was used as the atmospheric chemical transport model. Anthropogenic/pyrogenic particles emissions were prescribed at emission, whereas lithogenic emissions were dynamically simulated. Observations of aerosols and seawater filtration samples collected during research cruises in the North Pacific region were used in the analysis to evaluate the model. Observational data compiled by previous studies were also used.
The IMPACT model showed a good agreement with the East Asian dust deposition flux estimated based on individual quartz particle observations in the North Pacific. The IMPACT model also reproduced well the observed quartz content of coarse particles over the North Pacific Ocean. The IMPACT model reproduced well the concentration of soluble iron concentration in bulk samples over the North Pacific. The model also showed good agreement with the iron stable isotope ratios in fine particles and elemental ratios in coarse particles. These results indicate good performance of the model predictions for the anthropogenic and natural iron deposition flux into the North Pacific. In the presentation, analysis of historical simulations will be discussed.
The IMPACT model was used as the atmospheric chemical transport model. Anthropogenic/pyrogenic particles emissions were prescribed at emission, whereas lithogenic emissions were dynamically simulated. Observations of aerosols and seawater filtration samples collected during research cruises in the North Pacific region were used in the analysis to evaluate the model. Observational data compiled by previous studies were also used.
The IMPACT model showed a good agreement with the East Asian dust deposition flux estimated based on individual quartz particle observations in the North Pacific. The IMPACT model also reproduced well the observed quartz content of coarse particles over the North Pacific Ocean. The IMPACT model reproduced well the concentration of soluble iron concentration in bulk samples over the North Pacific. The model also showed good agreement with the iron stable isotope ratios in fine particles and elemental ratios in coarse particles. These results indicate good performance of the model predictions for the anthropogenic and natural iron deposition flux into the North Pacific. In the presentation, analysis of historical simulations will be discussed.