1. Iron in the Sargasso Sea (Bermuda Atlantic Time-series Study region) during summer: Eolian imprint, spatiotemporal variability, and ecological implications.
- Author
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Sedwick, P. N., Church, T. M., Bowie, A. R., Marsay, C. M., Ussher, S. J., Achilles, K. M., Lethaby, P. J., Johnson, R. J., Sarin, M. M., and McGillicuddy, D. J.
- Subjects
IRON ,AEROSOLS ,TIME series analysis ,SEDIMENTATION & deposition ,PHYTOPLANKTON ,BIOMASS - Abstract
We report iron measurements for water column and aerosol samples collected in the Sargasso Sea during July-August 2003 (summer 2003) and April-May 2004 (spring 2004). Our data reveal a large seasonal change in the dissolved iron (dFe) concentration of surface waters in the Bermuda Atlantic Time-series Study region, from ∼1-2 nM in summer 2003, when aerosol iron concentrations were high (mean 10 nmol m
-3 ), to ∼0.1-0.2 nM in spring 2004, when aerosol iron concentrations were low (mean 0.64 nmol m-3 ). During summer 2003, we observed an increase of ∼0.6 nM in surface water dFe concentrations over 13 days, presumably due to eolian iron input; an estimate of total iron deposition over this same period suggests an effective solubility of 3-30% for aerosol iron. Our summer 2003 water column profiles show potentially growth-limiting dFe concentrations (0.02-0.19 nM) coinciding with a deep chlorophyll maximum at 100-150 m depth, where phytoplankton biomass is typically dominated by Prochlorococcus during late summer. [ABSTRACT FROM AUTHOR]- Published
- 2005
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