Minor effect of physical size sorting on iron solubility of transported mineral dust
Observations show that the fractional solubility of Fe (FS-Fe, percentage of dissolved to total Fe) in dust aerosol increases considerably from 0.1 % in regions of high dust mass concentration to 80 % in remote regions where concentrations are low. Here, we combined laboratory geochemical measuremen...
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ftdoajarticles:oai:doaj.org/article:b91d256378b748b18e2b10ecf4f40cde 2023-05-15T17:32:34+02:00 Minor effect of physical size sorting on iron solubility of transported mineral dust Z. B. Shi M. T. Woodhouse K. S. Carslaw M. D. Krom G. W. Mann A. R. Baker I. Savov G. R. Fones B. Brooks N. Drake T. D. Jickells L. G. Benning 2011-08-01T00:00:00Z https://doi.org/10.5194/acp-11-8459-2011 https://doaj.org/article/b91d256378b748b18e2b10ecf4f40cde EN eng Copernicus Publications http://www.atmos-chem-phys.net/11/8459/2011/acp-11-8459-2011.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-11-8459-2011 1680-7316 1680-7324 https://doaj.org/article/b91d256378b748b18e2b10ecf4f40cde Atmospheric Chemistry and Physics, Vol 11, Iss 16, Pp 8459-8469 (2011) Physics QC1-999 Chemistry QD1-999 article 2011 ftdoajarticles https://doi.org/10.5194/acp-11-8459-2011 2022-12-31T01:24:44Z Observations show that the fractional solubility of Fe (FS-Fe, percentage of dissolved to total Fe) in dust aerosol increases considerably from 0.1 % in regions of high dust mass concentration to 80 % in remote regions where concentrations are low. Here, we combined laboratory geochemical measurements with global aerosol model simulations to test the hypothesis that the increase in FS-Fe is due to physical size sorting during transport. We determined the FS-Fe and fractional solubility of Al (FS-Al) in size-fractionated dust generated from two representative soil samples collected from known Saharan dust source regions using a customized dust re-suspension and collection system. The results show that the FS-Fe is size-dependent and ranges from 0.1–0.3 % in the coarse size fractions (>1 μm) to ~0.2–0.8 % in the fine size fractions (<1 μm). The FS-Al shows a similar size distribution to that of the FS-Fe. The size-resolved FS-Fe data were then combined with simulated dust mass concentration and size distribution data from a global aerosol model, GLOMAP, to calculate the FS-Fe of dust aerosol over the tropical and subtropical North Atlantic Ocean. We find that the calculated FS-Fe in the dust aerosol increases systematically from ~0.1 % at high dust mass concentrations (e.g., >100 μg m −3 ) to ~0.2 % at low concentrations (<100 μg m –3 ) due to physical size sorting (i.e., particle gravitational settling). These values are one to two orders of magnitude smaller than those observed on cruises across the tropical and sub-tropical North Atlantic Ocean under an important pathway of Saharan dust plumes for similar dust mass concentrations. Even when the FS-Fe of sub-micrometer size fractions (0.18–0.32 μm, 0.32–0.56 μm, and 0.56–1.0 μm) in the model is increased by a factor of 10 over the measured values, the calculated FS-Fe of the dust is still more than an order of magnitude lower than that measured in the field. Therefore, the physical sorting of dust particles alone is unlikely to be an important factor ... Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Atmospheric Chemistry and Physics 11 16 8459 8469 |
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topic |
Physics QC1-999 Chemistry QD1-999 |
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Physics QC1-999 Chemistry QD1-999 Z. B. Shi M. T. Woodhouse K. S. Carslaw M. D. Krom G. W. Mann A. R. Baker I. Savov G. R. Fones B. Brooks N. Drake T. D. Jickells L. G. Benning Minor effect of physical size sorting on iron solubility of transported mineral dust |
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Physics QC1-999 Chemistry QD1-999 |
description |
Observations show that the fractional solubility of Fe (FS-Fe, percentage of dissolved to total Fe) in dust aerosol increases considerably from 0.1 % in regions of high dust mass concentration to 80 % in remote regions where concentrations are low. Here, we combined laboratory geochemical measurements with global aerosol model simulations to test the hypothesis that the increase in FS-Fe is due to physical size sorting during transport. We determined the FS-Fe and fractional solubility of Al (FS-Al) in size-fractionated dust generated from two representative soil samples collected from known Saharan dust source regions using a customized dust re-suspension and collection system. The results show that the FS-Fe is size-dependent and ranges from 0.1–0.3 % in the coarse size fractions (>1 μm) to ~0.2–0.8 % in the fine size fractions (<1 μm). The FS-Al shows a similar size distribution to that of the FS-Fe. The size-resolved FS-Fe data were then combined with simulated dust mass concentration and size distribution data from a global aerosol model, GLOMAP, to calculate the FS-Fe of dust aerosol over the tropical and subtropical North Atlantic Ocean. We find that the calculated FS-Fe in the dust aerosol increases systematically from ~0.1 % at high dust mass concentrations (e.g., >100 μg m −3 ) to ~0.2 % at low concentrations (<100 μg m –3 ) due to physical size sorting (i.e., particle gravitational settling). These values are one to two orders of magnitude smaller than those observed on cruises across the tropical and sub-tropical North Atlantic Ocean under an important pathway of Saharan dust plumes for similar dust mass concentrations. Even when the FS-Fe of sub-micrometer size fractions (0.18–0.32 μm, 0.32–0.56 μm, and 0.56–1.0 μm) in the model is increased by a factor of 10 over the measured values, the calculated FS-Fe of the dust is still more than an order of magnitude lower than that measured in the field. Therefore, the physical sorting of dust particles alone is unlikely to be an important factor ... |
format |
Article in Journal/Newspaper |
author |
Z. B. Shi M. T. Woodhouse K. S. Carslaw M. D. Krom G. W. Mann A. R. Baker I. Savov G. R. Fones B. Brooks N. Drake T. D. Jickells L. G. Benning |
author_facet |
Z. B. Shi M. T. Woodhouse K. S. Carslaw M. D. Krom G. W. Mann A. R. Baker I. Savov G. R. Fones B. Brooks N. Drake T. D. Jickells L. G. Benning |
author_sort |
Z. B. Shi |
title |
Minor effect of physical size sorting on iron solubility of transported mineral dust |
title_short |
Minor effect of physical size sorting on iron solubility of transported mineral dust |
title_full |
Minor effect of physical size sorting on iron solubility of transported mineral dust |
title_fullStr |
Minor effect of physical size sorting on iron solubility of transported mineral dust |
title_full_unstemmed |
Minor effect of physical size sorting on iron solubility of transported mineral dust |
title_sort |
minor effect of physical size sorting on iron solubility of transported mineral dust |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
https://doi.org/10.5194/acp-11-8459-2011 https://doaj.org/article/b91d256378b748b18e2b10ecf4f40cde |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Atmospheric Chemistry and Physics, Vol 11, Iss 16, Pp 8459-8469 (2011) |
op_relation |
http://www.atmos-chem-phys.net/11/8459/2011/acp-11-8459-2011.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-11-8459-2011 1680-7316 1680-7324 https://doaj.org/article/b91d256378b748b18e2b10ecf4f40cde |
op_doi |
https://doi.org/10.5194/acp-11-8459-2011 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
11 |
container_issue |
16 |
container_start_page |
8459 |
op_container_end_page |
8469 |
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1766130751397429248 |