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

Authors

Peter N. Sedwick, Old Dominion UniversityFollow
Bettina M. Sohst, Old Dominion UniversityFollow
K. N. Buck
S. Caprara
R. J. Johnson
D. C. Ohnemus
L. E. Sofen
A. Tagliabue
B. S. Twining
Tara E. Williams, Old Dominion UniversityFollow

Document Type

Article

Publication Date

2023

DOI

10.1029/2022GL102594

Publication Title

Geophysical Research Letters

Volume

50

Issue

6

Pages

e2022GL102594 (1-9)

Abstract

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 >1 nM in late summer, with DFe inventories ranging from ∼30 to ∼80 μmol/m², 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.

Rights

© 2023 The Authors.

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made

Data Availability

Article states: "Data presented and discussed here, and associated metadata, are available from the U.S. National Science Foundation's Biological and Chemical Oceanography Data Management Office at: https://www.bco-dmo.org/project/822807."

Original Publication Citation

Sedwick, P. N., Sohst, B. M., Buck, K. N., Caprara, S., Johnson, R. J., Ohnemus, D. C., Sofen, L. E., Tagliabue, A., Twining, B. S., & Williams, T. E. (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), 1-9, Article e2022GL102594. https://doi.org/10.1029/2022GL102594

Repository Citation

Sedwick, Peter N.; Sohst, Bettina M.; Buck, K. N.; Caprara, S.; Johnson, R. J.; Ohnemus, D. C.; Sofen, L. E.; Tagliabue, A.; Twining, B. S.; and Williams, Tara E., "Atmospheric Input and Seasonal Inventory of Dissolved Iron in the Sargasso Sea: Implications for Iron Dynamics in Surface Waters of the Subtropical Ocean" (2023). OES Faculty Publications. 480.
https://digitalcommons.odu.edu/oeas_fac_pubs/480

ORCID

0000-0003-0663-8323 (Sedwick), 0000-0002-4983-5223 (Sohst)