The contribution of aeolian sand and dust to iron fertilizat
Details of Research
TitleThe contribution of aeolian sand and dust to iron fertilization of phytoplankton blooms in southwestern Ross Sea, AntarcticaAbstractIron is a limiting micronutrient for primary production in the Ross Sea, Antarctica. Recent observations reveal low dissolved Fe (dFe) concentrations in the Ross Sea polynya following high initial rates of primary production in summer, after the dFe winter reserve has been consumed. Significant new sources of dFe are therefore required to further sustain phytoplankton blooms. Iron from aeolian sand and dust (ASD) released from melting sea ice is one potential source. To constrain aeolian Fe inputs, we determined ASD mass accumulation rates and the total and soluble Fe content of ASD on sea ice in McMurdo Sound, southwestern (SW) Ross Sea. The mean mass accumulation rate was Â 1.5 g m -2 yr-1, total Fe content of this ASD was 4 Ã‚Â± 1 wt and the percentage of soluble Fe was 11 Ã‚Â± 1%. Our mean estimate of the bulk aeolian dFe flux of 122.1 ÃŽÅ'mol m-2 yr-1 for the McMurdo Sound region suggests that aeolian Fe can support between 9.0 ÃƒÃ‚Â— 109 and 4.1 ÃƒÃ‚Â— 1011 mol C yr-1 (0.1-4.9 Tg C yr-1) of new primary production. This equates to only Â 15% of new primary production in the SW Ross Sea, suggesting that aeolian dFe is a minor component of seasonal Fe supply. The very high ASD accumulation on sea ice in McMurdo Sound compared to other regions of Antarctica suggests that our results represent the upper limit of dFe supply to the ocean from this source in the Ross Sea. Key Points Fe sources are required to sustain phytoplankton blooms in the Ross Sea Local dust on sea ice contributes 2 orders of magnitude more than distal sources Fe solubility averages 11% resulting in a Fe flux of 6.8 mg m-2 yr-1 to SW Ross Sea Copyright2014. American Geophysical Union. All Rights Reserved.AcknowledgementsWe would like to thank Antarctica New Zealand and Scott Base personnel for logistics support. We are also grateful to Tim Haskell and the K131 event team for fieldwork support. Thanks also to event K043 and, in particular, Ana Aguilar-Islas for collecting samples at Granite Harbour and also equipment and advice on the Fe leaching method. Thanks to Lionel Carter, Ross Edwards, and Peter Sedwick for advice on an earlier version of this manuscript. V.H.L.W. would like to thank the following organizations for scholarship and other funding support: New Zealand Post and Antarctica New Zealand (New Zealand Post Scholarship), Victoria University of Wellington (J.L. and Kathleen Stewart Postgraduate Research Experience Travel Award, Kathleen Stewart Scholarship, and Antarctic Research Endowed Development Funds), and Golden Key (Asia-Pacific Travel Award). This project was funded by Victoria University of Wellington, GNS Science, and the Ministry of Science and Innovation through contracts: Global Change Through Time (CO5X0902), Antarctica-New Zealand Interglacial Climate Extremes ANZICEÃ¢Â€Â‰(VUW0704), the Past Antarctic Climate, and Future Implications (ANDRILL-NZ) Program (C05X1001). Isotopic analyses for provenance characterization were carried out at the Swedish Museum of Natural History and were supported by SYNTHESYS funding (project SE-TAF-212) made available by the European Community-Research Infrastructure Action under the FP6 Åštructuring the European Research Area ÌProgram. We would like to acknowledge the Norwegian Polar Institute for the use of the Qantarctica package. Additional thanks for the helpful comments and suggestions of two anonymous reviewers that aided in revision of this manuscript.
1st AuthorWinton, V.AuthorWinton, V.Dunbar, G.Bertler, N.Millet, M.-A.Delmonte, B.Atkins, C.Chewings, J.Andersson, P.Year2014JournalGlobal Biogeochemical CyclesVolume28Number4Pages423-436DOI10.1002/2013GB004574KeywordsBiomarkersDustPhytoplanktonSea iceSolubility, AntarcticaDissolved ironIron fertilizationIron solubilitiesMass accumulation ratesOrders of magnitudePhytoplankton bloomRoss Sea, Iron, climate conditionsconcentration (composition)dissolutioneolian depositironmeltingphytoplanktonpolynyaprimary productionsolubility, AntarcticaEast AntarcticaMcMurdo SoundRoss SeaSouthern Ocean, algae, rank5Author KeywordsAntarcticadissolved irondustiron solubilityphytoplanktonRoss Sea
TypeArticleCitationWinton, V., Dunbar, G., Bertler, N., Millet, M.-A., Delmonte, B., Atkins, C., Chewings, J. and Andersson, P. (2014) The contribution of aeolian sand and dust to iron fertilization of phytoplankton blooms in southwestern Ross Sea, Antarctica. Global Biogeochemical Cycles, 28(4):423-436 doi:10.1002/2013GB004574
Antarctica NZ (26th Nov 2018). The contribution of aeolian sand and dust to iron fertilizat . In Website Antarctica NZ. Retrieved 5th Dec 2020 04:26, from https://adam.antarcticanz.govt.nz/nodes/view/63826