Geophysical Research Letters · 2023 · 10 citations · 33 references
Natural SciencesEarth SciencesEnvironmental SciencesAir-sea InteractionAtmospheric ChemistryBiogeochemistryAtmospheric Oxidation ProcessesCarbon CycleGreenhouse Gas AccountingMarine Atmospheric ChemistryMicrobial BiogeochemistryOcean-atmosphere CouplingGaseous EmissionsHydroxyl Radical ChemistryHydroxyl Radical GenerationOcean Carbon SinkOcean ChemistryOceanic Biogeochemical ProcessesOceanic Mixing Processes
Abstract Hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) are potent greenhouse gases regulated under the Montreal Protocol and its amendments. Emission estimates generally use constant atmospheric lifetimes accounting for loss via hydroxyl radical (OH) reactions. However, chemistry‐climate models suggest OH increases after 1980, implying underestimated emissions. Further, HCFCs and HFCs are soluble in seawater and could be destroyed through in situ oceanic microbial activity. These ocean sinks are largely overlooked. Using a coupled atmosphere‐ocean model, we show that increases in modeled OH imply underestimated HCFC and HFC emissions by ∼10% near their respective peak emissions. Our model results also suggest that oceanic processes could lead to up to an additional 10% underestimation in these halocarbon emissions in the 2020s. Ensuring global compliance to the Protocol and accurate knowledge of contributions to global warming from these gases therefore requires understanding of these processes.
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