Marine Biogeochemical Control on Ozone Deposition Over the Ocean

Ozone in the lower atmosphere is a key air pollutant and a strong greenhouse gas. Deposition to the ocean represents a large removal mechanism for ozone but the processes driving its chemical removal on the sea surface remain poorly understood. Here we employ a novel technique to measure the chemical uptake of ozone on a research cruise in the Atlantic Ocean that spans 95 degrees latitude. We found that iodide and organics in surface seawater are both important reactants towards ozone deposition, with different relative contributions at different latitudes. Surprisingly, we found that deep waters also have substantial reactivity towards ozone, suggesting that when these waters are mixed to the surface, the nominally biologically inert organics are oxidised by reactions with ozone.

Reference: Yang, M.X., Phillips, D.P., Hopkins, F.E., et al. (2025). Marine biogeochemical control on ozone deposition over the ocean. Geophys. Res. Lett., 52(12), e2024GL113187. https://doi.org/10.1029/2024GL113187