Photoreductive dissolution of ferrihydrite by methanesulfinic acid: Evidence of a direct link between dimethylsulfide and iron-bioavailability

Authors

Anne M. Johansen, Central Washington University
Jennifer M. Key, Central Washington University

Document Type

Article

Department or Administrative Unit

Chemistry

Publication Date

7-27-2006

Abstract

Within open‐ocean regions where excess macronutrients are present, phytoplankton growth is limited by the bioavailability of iron supplied to these areas primarily within atmospheric aerosols of crustal origin. However, processes that control the abundance of biologically accessible iron in these aerosols are largely unknown. Here we show that dissolution of ferrihydrite, a surrogate iron(oxy)hydroxide phase found in atmospheric waters, is enhanced in the presence of methanesulfinic acid (MSIA, CH₃SO₂H, a dimethylsulfide (DMS) oxidation intermediate) in laboratory irradiation experiments with aqueous suspensions that simulate marine aerosol particles. The increased release of soluble Fe(II) is attributed to a species specific and direct photochemical reduction rather than a proton‐promoted effect, and suggests an efficient mechanism by which iron‐starved phytoplankton can actively increase aerosol iron‐bioavailability by increasing DMS emissions.

Comments

This article was originally published in Geophysical Research Letters. The full-text article from the publisher can be found here.

Recommended Citation

Johansen, A. M., and J. M. Key (2006), Photoreductive dissolution of ferrihydrite by methanesulfinic acid: Evidence of a direct link between dimethylsulfide and iron-bioavailability, Geophys. Res. Lett., 33, L14818, doi:10.1029/2006GL026010.

Journal

Geophysical Research Letters

Rights

Copyright 2006 by the American Geophysical Union.