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. Copyright 2005 by the American Geophysical Union.

Item Type:	Refereed Article
Research Division:	Earth Sciences
Research Group:	Oceanography
Research Field:	Chemical oceanography
Objective Division:	Environmental Management
Objective Group:	Marine systems and management
Objective Field:	Oceanic processes (excl. in the Antarctic and Southern Ocean)
UTAS Author:	Bowie, AR (Professor Andrew Bowie)
ID Code:	38609
Year Published:	2005
Web of Science® Times Cited:	100
Deposited By:	Chemistry
Deposited On:	2005-08-01
Last Modified:	2012-04-20
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