Warnock and Colleagues Study Ancient Atmospheric Dust Contributions to Southern Ocean

Posted on 3/2/23 8:11 AM

map showing chlorophyll concentrations in southern ocean

Warnock and colleagues analyzed sediments recovered from off the coast of Antarctica’s peninsula to understand changes in ancient atmospheric dust contribution to the Southern Ocean over time. This study was based on sediment cores taken aboard the JOIDES Resolution as part of International Ocean Discovery Program Expedition 382.  The paper, titled "Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years, studied the input of atmospheric dust to the Southern Ocean over time.

The study found that while dust enters the ocean during colder glacial (‘ice age’) periods, the Southern Ocean is much more ecologically active during interglacial times (warmer periods such as now). Dust enhances biological activity in the ocean, often by providing limiting nutrients like iron, and so has been suggested as a way to remove carbon from the atmosphere by fertilizing the oceans. These results show that approach is not likely to enhance biological activity, and therefore not helpful to bury carbon in ocean sediments. Instead, times of high productivity were seen to result from nutrients supplied from the deep ocean.

Full Reference

Weber, M.E., Bailey, I., Hemming, S.R. et al. Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years. Nat Commun 13, 2044 (2022). https://doi.org/10.1038/s41467-022-29642-5