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Biogeochemical iron budgets of the Southern Ocean south of Australia: Decoupling of iron and nutrient cycles in the subantarctic zone by the summertime supply
journal contribution
posted on 2023-05-17, 01:54 authored by Andrew BowieAndrew Bowie, Delphine LannuzelDelphine Lannuzel, Tomas Remenyi, Wagener, T, Lam, PJ, Philip BoydPhilip Boyd, Guieu, C, Ashley TownsendAshley Townsend, Trull, TClimate change is projected to significantly alter the delivery (stratification, boundary currents, aridification of landmasses, glacial melt) of iron to the Southern Ocean. We report the most comprehensive suite of biogeochemical iron budgets to date for three contrasting sites in subantarctic and polar frontal waters south of Australia. Distinct regional environments were responsible for differences in the mode and strength of iron supply mechanisms, with higher iron stocks and fluxes observed in surface northern subantarctic waters, where atmospheric iron fluxes were greater. Subsurface waters southeast of Tasmania were also enriched with particulate iron, manganese and aluminum, indicative of a strong advective source from shelf sediments. Subantarctic phytoplankton blooms are thus driven by both seasonal iron supply from southward advection of subtropical waters and by wind-blown dust deposition, resulting in a strong decoupling of iron and nutrient cycles. We discuss the broader global significance our iron budgets for other ocean regions sensitive to climate-driven changes in iron supply.
History
Publication title
Global Biogeochemical CyclesVolume
23Issue
4Article number
GB4034Number
GB4034Pagination
1-14ISSN
0886-6236Department/School
Institute for Marine and Antarctic StudiesPublisher
Amer Geophysical UnionPlace of publication
2000 Florida Ave Nw, Washington, USA, Dc, 20009Rights statement
Copyright © 2009 American Geophysical UnionRepository Status
- Restricted