Potentially bioavailable iron delivery by iceberg-hosted sediments and atmospheric dust to the polar oceans
Iceberg-hosted sediments and atmospheric dust transport potentially bioavailable iron to the Arctic and Southern oceans as ferrihydrite. Ferrihydrite is nanoparticulate and more soluble, as well as potentially more bioavailable, than other iron (oxyhydr)oxide minerals (lepidocrocite, goethite, and h...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-07-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/13/3887/2016/bg-13-3887-2016.pdf |
| _version_ | 1811192278505488384 |
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| author | R. Raiswell J. R. Hawkings L. G. Benning A. R. Baker R. Death S. Albani N. Mahowald M. D. Krom S. W. Poulton J. Wadham M. Tranter |
| author_facet | R. Raiswell J. R. Hawkings L. G. Benning A. R. Baker R. Death S. Albani N. Mahowald M. D. Krom S. W. Poulton J. Wadham M. Tranter |
| author_sort | R. Raiswell |
| collection | DOAJ |
| description | Iceberg-hosted sediments and atmospheric dust transport potentially
bioavailable iron to the Arctic and Southern oceans as ferrihydrite.
Ferrihydrite is nanoparticulate and more soluble, as well as potentially more
bioavailable, than other iron (oxyhydr)oxide minerals (lepidocrocite,
goethite, and hematite). A suite of more than 50 iceberg-hosted sediments
contain a mean content of 0.076 wt % Fe as ferrihydrite, which produces
iceberg-hosted Fe fluxes ranging from 0.7 to 5.5 and 3.2 to 25 Gmoles yr<sup>−1</sup>
to the Arctic and Southern oceans respectively. Atmospheric dust (with little
or no combustion products) contains a mean ferrihydrite Fe content of
0.038 wt % (corresponding to a fractional solubility of ∼ 1 %)
and delivers much smaller Fe fluxes (0.02–0.07 Gmoles yr<sup>−1</sup> to the
Arctic Ocean and 0.0–0.02 Gmoles yr<sup>−1</sup> to the Southern Ocean). New
dust flux data show that most atmospheric dust is delivered to sea ice where
exposure to melting/re-freezing cycles may enhance fractional solubility, and
thus fluxes, by a factor of approximately 2.5. Improved estimates for these
particulate sources require additional data for the iceberg losses during
fjord transit, the sediment content of icebergs, and samples of atmospheric
dust delivered to the polar regions. |
| first_indexed | 2024-04-11T23:49:56Z |
| format | Article |
| id | doaj.art-91e3d610562a4efa8ce32ff6a77289fb |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-04-11T23:49:56Z |
| publishDate | 2016-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-91e3d610562a4efa8ce32ff6a77289fb2022-12-22T03:56:30ZengCopernicus PublicationsBiogeosciences1726-41701726-41892016-07-0113133887390010.5194/bg-13-3887-2016Potentially bioavailable iron delivery by iceberg-hosted sediments and atmospheric dust to the polar oceansR. Raiswell0J. R. Hawkings1L. G. Benning2A. R. Baker3R. Death4S. Albani5N. Mahowald6M. D. Krom7S. W. Poulton8J. Wadham9M. Tranter10Cohen Biogeochemistry Laboratory, School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UKBristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UKCohen Biogeochemistry Laboratory, School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UKLaboratory for Global Marine and Atmospheric Chemistry, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UKBristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UKDepartment of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York, USADepartment of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York, USACohen Biogeochemistry Laboratory, School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UKCohen Biogeochemistry Laboratory, School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UKBristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UKBristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UKIceberg-hosted sediments and atmospheric dust transport potentially bioavailable iron to the Arctic and Southern oceans as ferrihydrite. Ferrihydrite is nanoparticulate and more soluble, as well as potentially more bioavailable, than other iron (oxyhydr)oxide minerals (lepidocrocite, goethite, and hematite). A suite of more than 50 iceberg-hosted sediments contain a mean content of 0.076 wt % Fe as ferrihydrite, which produces iceberg-hosted Fe fluxes ranging from 0.7 to 5.5 and 3.2 to 25 Gmoles yr<sup>−1</sup> to the Arctic and Southern oceans respectively. Atmospheric dust (with little or no combustion products) contains a mean ferrihydrite Fe content of 0.038 wt % (corresponding to a fractional solubility of ∼ 1 %) and delivers much smaller Fe fluxes (0.02–0.07 Gmoles yr<sup>−1</sup> to the Arctic Ocean and 0.0–0.02 Gmoles yr<sup>−1</sup> to the Southern Ocean). New dust flux data show that most atmospheric dust is delivered to sea ice where exposure to melting/re-freezing cycles may enhance fractional solubility, and thus fluxes, by a factor of approximately 2.5. Improved estimates for these particulate sources require additional data for the iceberg losses during fjord transit, the sediment content of icebergs, and samples of atmospheric dust delivered to the polar regions.http://www.biogeosciences.net/13/3887/2016/bg-13-3887-2016.pdf |
| spellingShingle | R. Raiswell J. R. Hawkings L. G. Benning A. R. Baker R. Death S. Albani N. Mahowald M. D. Krom S. W. Poulton J. Wadham M. Tranter Potentially bioavailable iron delivery by iceberg-hosted sediments and atmospheric dust to the polar oceans Biogeosciences |
| title | Potentially bioavailable iron delivery by iceberg-hosted sediments and
atmospheric dust to the polar oceans |
| title_full | Potentially bioavailable iron delivery by iceberg-hosted sediments and
atmospheric dust to the polar oceans |
| title_fullStr | Potentially bioavailable iron delivery by iceberg-hosted sediments and
atmospheric dust to the polar oceans |
| title_full_unstemmed | Potentially bioavailable iron delivery by iceberg-hosted sediments and
atmospheric dust to the polar oceans |
| title_short | Potentially bioavailable iron delivery by iceberg-hosted sediments and
atmospheric dust to the polar oceans |
| title_sort | potentially bioavailable iron delivery by iceberg hosted sediments and atmospheric dust to the polar oceans |
| url | http://www.biogeosciences.net/13/3887/2016/bg-13-3887-2016.pdf |
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