Theme 5: Ocean biogeochemical control on atmospheric chemistry

Ocean emissions of reactive gases and aerosols influence atmospheric photochemistry and oxidising capacity, air quality, and stratospheric ozone. Theme 5 focuses on the role of marine biogeochemical controls on the sea-surface and atmospheric chemistry of reactive and climate active gases, and how that will evolve in the changing ocean and atmosphere. Complete reliable information is still missing on chemical characterisation of sea surface emissions of reactive volatile gases (e.g., organohalogens, VOCs, OVOCs), how these volatiles are formed at the sea surface, what is their fate and lifetime in the atmosphere and how a changing ocean is affecting the biogeochemistry of these emissions.

Theme 5 team


Team leaders

Anoop Mahajan (India,
Nadja Steiner (Canada,
Liselotte Tinel (France,

Team members

Katye Altieri (South Africa,
Marcela Cornejo D'Ottone (Chile,
Julie Dinasquet (United States,
Christian George (France,
Karin Kvale (New Zealand,
Mohd Talib Latif (Malaysia,
Chonlin Lee (China, Taiwan,
Maurice Levasseur (Canada,
Stelios Myriokefalitakis (Greece,
Jurgita Ovadnevaite (Ireland,
Karine Sellegri (France,
Yee Jun Tham (China,
Rainer Volkamer (United States,
Oliver Wurl (Germany,
Lei Xue (United States,

Processes and impacts/stressors associated with long-lived greenhouse gases.

Simplified schematic depiction of the most important couplings between ocean biogeochemical cycles and atmospheric chemistry.

Research questions

Key questions to be addressed within this theme are:

  • What are the sequential biogeochemical controls and reactivity across the air-sea interface on the release of reactive gases into the atmosphere?
  • What are the characteristics and chemical interactions of biotic and abiotic volatile organic compounds from ocean in the atmosphere?
  • How do photochemistry, multiphase and oxidation chemistry influence the fate of atmospheric gases and precursor materials for aerosol formation in the atmosphere?
  • How will future changes in ocean biogeochemistry and anthropogenic emissions (NOX, VOCs) interact to influence tropospheric photochemistry and stratospheric ozone?
  • What is the lifetime of climate active trace gases (e.g. DMS, halogens)


Priorities - Methodology & Tools

Process-oriented campaigns
Conduct process-oriented campaigns to simultaneously study surface ocean cycling, sea-air gas exchange and atmospheric chemistry. These will include marine biogeochemical studies to determine the link between gas emissions and the biological factors controlling their production (e.g., bloom dynamics, and microbial ecology). The atmospheric component will provide the rates and mechanisms of atmospheric cycling of reactive emissions including their potential feedback processes with the ocean and anthropogenic pollution in coastal areas. The provision of information on reactive gases from satellite instruments will be an important component of such studies. For Theme 5, the focus of these studies will be on reactive trace gases cycles in the marine environment.
Controlled experiments
Define proxies of the bulk reactive trace gases including aerosol precursors emissions and impacts for use for controlled/in situ/satellite observations/modelling. Develop standardized protocols for their determination. Coordinate and shared strategy. Conduct laboratory investigations of the reaction mechanisms and rates of formation of reactive volatiles at the sea surface. Develop concept/conduct SML based experiment necessary to understand reaction mechanisms and rates of formation of reactive volatiles at the sea surface.
Combined modelling studies

Combine modelling studies to improve mechanisms at the process level and upscale from the local and regional scale to the global scale to study climate and biogeochemical impacts. These modelling studies must involve information from the remote sensing of reactive gases. Develop methodology to reach closure between satellite, in situ and controlled observations.





Planned activities

Research programmes on biogeochemical control on atmospheric chemistry
  • China - Cruises for the investigation of seasonal variations of DMS, CO, volatile halocarbons, and nonmethane hydrocarbons are planned in the Yangtze River Estuary
  • Taiwan - Aerosol, Land, Ocean, Human, Air (ALOHA) is the central theme of the SOLAS in Taiwan in the coming years. The start of the submitted proposal "Aerosol, Land, Ocean, Human, Air (ALOHA) - From the characteristics of aerosols in a harbor-industrial-urban city to probe the impacts of air pollution towards atmosphere and marine ecosystem and its social impacts" is expected in 2022
  • India - Expeditions in the Arabian Sea, Bay of Bengal and the Indian Ocean have been planned onboard ORV Sagar Kanya and other chartered scientific vessels(s) for:

- Studying the influence of seabed features & open ocean exchanges on coastal ocean dynamics
- The Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA) consists of moored observation buoys in the IO to collect meteorological and oceanographic data
- Biogeochemistry of trace elements and isotopes
- Ocean acidification along the east coast of India
- Assessing carbon budget in the Southern Ocean. Research cruise details can be availed at:;

  • Australia:

- Ongoing atmospheric measurements of the RV Investigator
- Numerous major field campaigns as part of the PICCAASO initiative ( with numerous Australian led campaigns. See website for details. Southern Ocean Time Series (SOTS) voyage, IN2022_V03, including at-sea aerosol and rain sampling for trace elements and major ions

  • SOLAS Southeast Asia Workshop, 23rd August 2022

  • The 6th Xiamen Symposium on Marine Environmental Sciences (XMAS-VI) will be held in Xiamen from January 9 - 12, 2023. XMAS-VI will focus on Multidisciplinary and Solution Sciences for a Sustainable and Healthy Ocean.

  • EGU SOLAS/GESAMP session: AS2.6 Air-sea Chemical Fluxes: Impacts on Biogeochemistry and Climate" April 23-28 2023, in Vienna. Deadline for abstract submission January 10th, 2023
Research highlights

1.  Mapping gaseous dimethylamine, trimethylamine, ammonia, and their particulate counterparts in the marine atmosphere of China's marginal seas (Theme 4, 5)

Chen, D., Shen, Y., Wang, J., et al., (2021). Mapping gaseous dimethylamine, trimethylamine, ammonia, and their particulate counterparts in marine atmospheres of China's marginal seas–Part 1: Differentiating marine emission from continental transport. Atmos. Chem. Phys., 21, 16413–16425.

2.  Surface ocean microbiota as a source of benzenoids to the remote marine atmosphere

Rocco, M., Dunne, E., Peltola, M., et al., (2021).Oceanic phytoplankton are a potentially important source of benzenoids to the remote marine atmosphere.Commun. Earth Environ., 2, 175.

3.  Iodine geochemistry

Spolaor, A., Burgay, F., Fernandez, R.P. et al., (2021). Antarctic ozone hole modifies iodine geochemistry on the Antarctic Plateau. Nat. Commun., 12, 5836.

4.  Gas-atmosphere interaction

Jackson R.L., Gabric, A.j., Matrai, P.A., et al., (2021). Parameterizing the impact of seawater temperature and irradiance on dimethylsulfide (DMS) in the Great Barrier Reef and the contribution of coral reefs to the global sulfur cycle. J. Geophys. Res. Oceans, 126(3), e2020JC016783.

Uning, R., Latif, M.T., Hamid, H.H.A., et al., (2021). Sea-to-air fluxes of isoprene and monoterpenes in the coastal upwelling region of peninsular Malaysia. ACS Earth Space Chem., 5(12), 3429-3436.

Zhu, Y., Wang, Y., Zhou, X., et al., (2022). An investigation into the chemistry of HONO in the marine boundary layer at Tudor Hill Marine Atmospheric Observatory in Bermuda. Atmos. Chem. Phys., 22, 6327-6346.

5.  Emissions of pollutants from coastal water to the atmosphere

Pendergraft, M.A., Grimes, D.J., Giddings, S.N., et al., (2021). Airborne transmission pathway for coastal water pollution. PeerJ, 9, e11358.