Changing atmospheric acidity as a modulator of nutrient deposition and ocean biogeochemistry

Anthropogenic emissions to the atmosphere have altered the acidity of aerosol, cloudwater and precipitation over much of the marine atmosphere. Acidity changes alter the chemical speciation of nitrogen, affecting its partitioning between the gas and particulate phases. Iron, phosphorus and other trace elements are impacted because exposure to acidic environments during atmospheric transport increases their solubility. These changes affect the magnitude, distribution and deposition mode of individual nutrients supplied to the ocean, the extent to which nutrient deposition interacts with the sea-surface microlayer, and the relative abundances of soluble nutrients in atmospheric deposition.  Atmospheric acidity change therefore affects ecosystem composition, as well as overall marine productivity. These effects will continue to evolve with changing anthropogenic emissions in the future.

This publication is resulted from the SOLAS co-sponsored GESAMP Working Group 38 workshop on ‘Changing Atmospheric Acidity and its Impacts on the Oceanic Solubility of Nutrients’. For more information about this workshop here.

Reference: Baker, A., Kanakidou, M., Nenes, A., et al. (2021). Changing atmospheric acidity as a modulator of nutrient deposition and ocean biogeochemistry, Science Advances, 7, eabd8800. https://doi.org/10.1126/sciadv.abd8800