139120 - Origin, transport and deposition of aerosol iron_OA.pdf (911.38 kB)
Origin, transport and deposition of aerosol iron to Australian coastal waters
journal contribution
posted on 2023-05-20, 14:33 authored by Perron, MMG, Bernadette ProemseBernadette Proemse, Strzelec, M, Melanie EastMelanie East, Philip BoydPhilip Boyd, Estrella Sanz RodriguezEstrella Sanz Rodriguez, Brett PaullBrett Paull, Andrew BowieAndrew BowieAustralia is a major source of Fe-laden dust to the anemic marine phytoplankton in the Southern Ocean and to Southern Hemisphere (SH) low latitudes diazotrophic bacteria. However, the paucity of observations and laboratory experiments on SH aerosols biases model predictions of atmospheric Fe deposition to the southern oceans and the subsequent response of ocean productivity. As a result of an extensive shipboard aerosol sampling effort, this study presents laboratory measurements of aerosol Fe concentrations, solubilities and fluxes and analysis of chemical tracers, highlighting the large heterogeneity between aerosol Fe sources in 5 coastal regions around Australia. While dust-sourced high Fe loadings and low Fe solubilities (5%) aerosols dominate the atmospheric burden of the western coasts of Australia, much lower Fe concentrations but greater Fe solubilities (10.5% and 13%) were measured in aerosols along the east coast which was attributed to solubility-enhancing atmospheric reactions with anthropogenic pollutants. Surprisingly high aerosol Fe solubilities (>20%) in northern Australia aerosols were associated with direct emissions or atmospheric reactions with bushfire emissions at tropical latitudes, which accounted for 49% of the total (sum) atmospheric dry deposition flux of labile Fe measured across the continent's surrounding seawaters in this study.
Funding
Australian Research Council
History
Publication title
Atmospheric EnvironmentVolume
228Article number
117432Number
117432Pagination
1-13ISSN
1352-2310Department/School
Institute for Marine and Antarctic StudiesPublisher
Pergamon-Elsevier Science LtdPlace of publication
The Boulevard, Langford Lane, Kidlington, Oxford, England, Ox5 1GbRights statement
Copyright 2020 Elsevier Ltd.Repository Status
- Restricted