Journet E., Desboeufs K. V., Caquineau Sandrine, Colin J. L. (2008). Mineralogy as a critical factor of dust iron solubility - art. no. L07805. Geophysical Research Letters, 35 (7), p. NIL_47-NIL_51. ISSN 0094-8276.
Titre du document
Mineralogy as a critical factor of dust iron solubility - art. no. L07805
Journet E., Desboeufs K. V., Caquineau Sandrine, Colin J. L.
Source
Geophysical Research Letters, 2008,
35 (7), p. NIL_47-NIL_51 ISSN 0094-8276
To understand the impact of dust deposition on ocean primary productivity, the evaluation of dust input is not sufficient, and the soluble iron supply is also needed. Measurements of iron in aerosols suggest a much higher solubility than in soil, implying substantial atmospheric processing of chemical or physical nature. Here, we have investigated the effect of the mineralogy on iron solubility. We have measured iron solubility from some minerals commonly found in dust (clay, feldspar and iron (hydr-)oxides). Firstly, we observe a greater solubility of iron resulting from clays (similar to 4%) in comparison to iron (hydr-) oxides (<1%), independently of specific surface of minerals. Secondly, by considering amount of dissolved iron and the mineralogical composition of dust, our results indicate that dissolved iron fraction mainly comes from clay dissolution in contrast to that assumed in some biogeochemical models. In consequence, it appears that iron solubility is closely linked to the mineralogical composition of aerosol.
