Biogenic Volatile Organic Compound Emissions in Ocean-Atmosphere Interactions

Biogenic volatile organic compounds (BVOCs) emitted from marine systems represent a dynamic interface between the ocean and atmosphere, influencing atmospheric chemistry, aerosol formation and climate processes. Key BVOCs such as isoprene and monoterpenes arise principally from phytoplankton, seaweed and surface microlayer reactions, while additional compounds—acetone, methanol, benzene and toluene—can originate from both biological and photochemical pathways. Emissions vary with biological productivity, light intensity, temperature and sea-ice cover, and are modulated by physical transport across the sea-air boundary. Once in the atmosphere, BVOCs react with oxidants (notably the hydroxyl radical), forming secondary organic aerosols (SOA) that affect cloud microphysics and radiative forcing. Accurate quantification of marine BVOC fluxes remains challenging due to limited in-situ measurements, the diversity of emission pathways and model uncertainties. Improved representation of these processes in Earth system models is essential for understanding pre-industrial baselines, present-day air quality and future climate feedbacks.

Research from Nature Portfolio

Recent field measurements across the Southern Ocean during the austral summer have revealed isoprene concentrations in marine air far exceeding model predictions, particularly in marginal ice zones. Observed sea-to-air fluxes exceed current estimates by over an order of magnitude, suggesting that high-latitude emissions substantially lower regional hydroxyl radical concentrations and alter atmospheric oxidation capacity. In parallel, investigations into interfacial photochemistry at the ocean surface have identified an abiotic source of organic vapours whose global magnitude rivals that of biological emissions. Photochemical production at the air–sea interface is now recognised as a major contributor to marine BVOC budgets, with potential to supply a large fraction of SOA over remote waters and to vary seasonally with solar irradiance and surface composition.

Biogenic Volatile Organic Compound Emissions in Ocean-Atmosphere Interactions publication trend

The graph below shows the total number of articles in biogenic volatile organic compound emissions in ocean-atmosphere interactions across all publications each year (not limited to Nature Index journals).

Technical terms

Biogenic volatile organic compounds (BVOCs): Organic gases produced by living organisms that readily evaporate and enter the atmosphere.

Sea-to-air flux: The transfer rate of a substance from the ocean surface into the overlying atmosphere, typically expressed per unit area per unit time.

Secondary organic aerosol (SOA): Fine particulate matter formed by atmospheric oxidation of volatile organic compounds, influencing cloud formation and radiative balance.

Hydroxyl radical (OH): A highly reactive atmospheric oxidant that initiates the breakdown of many trace gases, including BVOCs.

Interfacial photochemistry: Light-driven chemical reactions occurring at the boundary between air and water that generate reactive organic vapours independent of biological activity.

References

1. Atmospheric isoprene measurements reveal larger-than-expected Southern Ocean emissions. Nature Communications (2024).
2. Marine biogenic emissions of benzene and toluene and their contribution to secondary organic aerosols over the polar oceans. Science Advances (2023).
3. Microbial cycling of isoprene, the most abundantly produced biological volatile organic compound on Earth. The ISME Journal: Multidisciplinary Journal of Microbial Ecology (2018).
4. Identification and characterisation of isoprene‐degrading bacteria in an estuarine environment. Environmental Microbiology (2017).
5. Interfacial photochemistry at the ocean surface is a global source of organic vapors and aerosols. Nature Communications (2018).
6. Potential controls of isoprene in the surface ocean. Global Biogeochemical Cycles (2017).