Projects per year
Abstract
Iron (Fe) is a key micronutrient regulating primary productivity in many parts of the global ocean. Dust deposition is an important source of Fe to the surface ocean, but most of this Fe is biologically unavailable. Atmospheric processing and reworking of Fe in dust aerosol can increase the bioavailable Fe inputs to the ocean, yet the processes are not well understood. Here, we experimentally simulate and model the cycling of Fe-bearing dust between wet aerosol and cloud droplets. Our results show that insoluble Fe in dust particles readily dissolves under acidic conditions relevant to wet aerosols. By contrast, under the higher pH conditions generally relevant to clouds, Fe dissolution tends to stop, and dissolved Fe precipitates as poorly crystalline nanoparticles. If the dust-bearing cloud droplets evaporated again (returning to the wet aerosol stage with low pH), those neo-formed Fe nanoparticles quickly redissolve, while the refractory Fe-bearing phases continue to dissolve gradually. Overall, the duration of the acidic, wet aerosol stage ultimately increases the amount of potentially bioavailable Fe delivered to oceans, while conditions in clouds favor the formation of Fe-rich nanoparticles in the atmosphere.
Original language | English |
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Pages (from-to) | 1472-1477 |
Journal | Environmental Science & Technology |
Volume | 49 |
Issue number | 3 |
Early online date | 9 Jan 2015 |
DOIs | |
Publication status | Published - 3 Feb 2015 |
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Dive into the research topics of 'Atmospheric processing outside clouds increases soluble iron in mineral dust'. Together they form a unique fingerprint.Projects
- 2 Finished
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Are iron nanoparticles in wet deposition a potential source of bioavailable Fe to marine algae?
Natural Environment Research Council
1/07/13 → 31/12/14
Project: Research Councils
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Novel approaches to the evaluation of iron and phosphorus availability in dust deposited to the oceans
Natural Environment Research Council
4/07/11 → 10/07/15
Project: Research Councils