Iron Dissolution from Patagonian Dust in the Southern Ocean: Under Present and Future Conditions

The input of desert dust as a source of trace metals in the Southern Ocean (SO) has been previously studied, but the dissolution process of the limiting micronutrient iron (Fe) in surface waters remains poorly understood. We investigated Fe dissolution from Patagonian dust, the main natural dust source in the SO, under present and projected future conditions (warming, acidification, increase of dust input and light). Future changes would not significantly alter the mineralogy and redox speciation of Fe in the dust. But the dissolution rate would decrease by half under future conditions (from 3.8 to 1.6% d-1). Thus, anticipated doubling of dust input will unlikely provide more dissolved Fe in seawater, probably not alleviating Fe limitation in the SO.

Reference: Demasy, C., Boye, M., Lai, B., et al., (2024). Iron dissolution from Patagonian dust in the Southern Ocean: under present and future conditions. Front. Mar. Sci., 11, 1363088. https://doi.org/10.3389/fmars.2024.1363088