Atmospheric acidification of mineral aerosols: a source of bioavailable phosphorus for the oceans
Loading...
Date
2011-07-01
Authors
Nenes, Athanasios
Krom, Michael D.
Mihalopoulos, Nikos
Van Cappellen, Philippe
Shi, Zongbo
Bougiatioti, Aikaterini
Zarmpas, Pavlos
Herut, Barak
Journal Title
Journal ISSN
Volume Title
Publisher
European Geosciences Union
Abstract
Primary productivity of continental and marine ecosystems is often limited or co-limited by phosphorus. Deposition of atmospheric aerosols provides the major external source of phosphorus to marine surface waters. However, only a fraction of deposited aerosol phosphorus is water soluble and available for uptake by phytoplankton. We propose that atmospheric acidification of aerosols is a prime mechanism producing soluble phosphorus from soil-derived minerals. Acid mobilization is expected to be pronounced where polluted and dust-laden air masses mix. Our hypothesis is supported by the soluble compositions and reconstructed pH values for atmospheric particulate matter samples collected over a 5-yr period at Finokalia, Crete. In addition, at least tenfold increase in soluble phosphorus was observed when Saharan soil and dust were acidified in laboratory experiments which simulate atmospheric conditions. Aerosol acidification links bioavailable phosphorus supply to anthropogenic and natural acidic gas emissions, and may be a key regulator of ocean biogeochemistry.
Description
Keywords
Thermodynamic-Equilibrium Model, Eastern Mediterranean-Sea, Air-Quality Models, Chemical-Composition, Dust, Limitation, Marine, Productivity, Fluorapatite, Ecosystems