Earth, wind, fire, and pollution: aerosol nutrient sources and impacts on ocean biogeochemistry

Owing to the large spatiotemporal variability in aerosols from multiple sources, combined with knowledge that biota utilises different nutrients differently, it is crucial to be specific about which aerosols enter which ecosystems at which times and by how much. This review examined the contribution of nutrient-bearing aerosols from desert dust, wildfire, volcanic, and anthropogenic sources to ocean deposition fluxes of nitrogen, phosphorus, and iron. Globally averaged, in situ aerosol addition experiments (n=70) suggest that atmospheric deposition does favour chlorophyll-a production (∼80%) and that a mixed or non-dust source may stimulate production 50% more than pure-dust aerosol. Particular attention is thus given to reviewing non-dust nutrient aerosols. The review concludes with a case study of Australian aerosols and investigates how the 2019-2020 megafire impacted Southern Ocean net primary productivity.

Reference: Hamilton, D. S., Perron, M. M. G., Bond, T. C., et al., (2022). Earth, wind, fire, and pollution: aerosol nutrient sources and impacts on ocean Biogeochemistry. Annu. Rev. Mar. Sci., 14. https://doi.org/10.1146/annurev-marine-031921-013612.