Atmospheric Input and Seasonal Inventory of Dissolved Iron in the Sargasso Sea: Implications for Iron Dynamics in Surface Waters of the Subtropical Ocean



Sedwick, PN, Sohst, BM, Buck, KN, Caprara, S, Johnson, RJ, Ohnemus, DC, Sofen, LE, Tagliabue, A ORCID: 0000-0002-3572-3634, Twining, BS and Williams, TE
(2023) Atmospheric Input and Seasonal Inventory of Dissolved Iron in the Sargasso Sea: Implications for Iron Dynamics in Surface Waters of the Subtropical Ocean. GEOPHYSICAL RESEARCH LETTERS, 50 (6).

Access the full-text of this item by clicking on the Open Access link.

Abstract

<jats:title>Abstract</jats:title><jats:p>Constraining the role of dust deposition in regulating the concentration of the essential micronutrient iron in surface ocean waters requires knowledge of the flux of seawater‐soluble iron in aerosols and the replacement time of dissolved iron (DFe) in the euphotic zone. Here we estimate these quantities using seasonally resolved DFe data from the Bermuda Atlantic Time‐series Study region and weekly‐scale measurements of iron in aerosols and rain from Bermuda during 2019. In response to seasonal changes in vertical mixing, primary production and dust deposition, surface DFe concentrations vary from ∼0.2 nM in early spring to &gt;1 nM in late summer, with DFe inventories ranging from ∼30 to ∼80 μmol/m<jats:sup>2</jats:sup>, respectively, over the upper 200 m. Assuming the upper ocean approximates steady state for DFe on an annual basis, our aerosol and rainwater data require a mean euphotic‐zone residence time of ∼0.8–1.9 years for DFe with respect to aeolian input.</jats:p>

Item Type: Article
Uncontrolled Keywords: dissolved iron, residence time, aeolian deposition, Bermuda Atlantic Time-series Study
Divisions: Faculty of Science and Engineering > School of Environmental Sciences
Depositing User: Symplectic Admin
Date Deposited: 10 May 2023 19:52
Last Modified: 21 Aug 2023 03:07
DOI: 10.1029/2022GL102594
Open Access URL: https://doi.org/10.1029/2022GL102594
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3170281