Theme 1: Greenhouse Gases and the Oceans

To better quantify oceanic GHG budgets and air-sea fluxes and improve understanding of associated processes, we highly recommend detailed analyses of GHG fluxes and processes in key regions. These include the eastern boundary upwelling systems (EBUS), western boundary current systems, Southern Ocean, Artic Ocean land-ocean continuum, oceanic Oxygen Minimum Zones (OMZs). Recommended approaches include (i) higher resolution numerical models and artificial intelligence (e.g., machine learning), (ii) novel observing tools and methods (e.g., remote sensing technology, in situ biogeochemical sensors, isotope, and tracer methods), (iii) diverse platforms, including ships, autonomous platforms (e.g., Argo floats, gliders), moorings, and Saildrones. Sustained time-series observations at fixed sites are also necessary to characterize the seasonal and interannual variability and long-term trends in regional GHG fluxes.s.

Improved quantification of ocean-atmosphere CO₂ fluxes has been achieved by combining surface-ocean carbon measurements with a range of mapping methods including spatial interpolation, multi-variate regression, and neural network analyses. These methods are valuable tools and should be applied to ocean measurements of N₂O and CH₄ to provide improved quantification of other GHG fluxes.

Significant questions remain in predicting how future oceanic GHG fluxes will evolve in response to the combined impacts of multiple environmental stressors (e.g., ocean warming, deoxygenation, and acidification) and the reduction in CO₂ emissions. Successful prediction of future GHG evolution requires the development of ocean biogeochemical models able to represent the key physical, chemical, and ecosystem processes and their interactions, in order to reliably estimate the impacts of anthropogenic pressures and environmental changes on the ocean GHG fluxes. Relevant biogeochemical and ecosystem component models should also be incorporated into Earth System Models (ESMs) employed for climate prediction to enable accurate quantification of the important GHG-climate feedbacks.

AMT4oceanSatFlux: https://amt4oceansatflux.org/

Boknis Eck: http://www.bokniseck.de

ICOS: https://www.icos-cp.eu/

ORCHESTRA: https://www.bas.ac.uk/project/orchestra/

REEBUS: https://www.ebus-climate-change.de/reebus

SOCCOM: https://soccom.princeton.edu/

SO-CHIC: http://www.sochic-h2020.eu/

RoSES:  http://www.nerc.ac.uk/research/funded/programmes/roses/

EWARP: https://soos.aq/news/ewarp

Greenfeedback

The community-led Surface Ocean CO₂ Atlas (www.socat.info) is used for quantification of ocean CO₂ uptake and ocean acidification and for evaluation of climate models and sensor data. SOCAT has an annual release of quality-controlled in situ surface ocean fCO₂ (fugacity of CO₂) measurements for the global ocean and coastal seas from 1957 onwards. The value chain based on in situ inorganic carbon measurements of the ocean, of which SOCAT is part, provides policy makers with vital information in climate negotiations.

Following on the successes of the previous SOLAS/IMBER Carbon group (SIC), a new Integrated Ocean Carbon Research Group has been formed. This initiative is jointly sponsored by IOC, IMBER, SOLAS, IOCCP, GCP, CLIVAR, and WCRP. The group will identify the key research needs for ocean carbon science for the next decade, develop strategies to address these needs, and address the links to societal and policy applications. An initial expert group workshop was held at the International Oceanographic Commission, Paris, in October 2019; The group has published the report: “Integrated ocean carbon research: a summary of ocean carbon research, and vision of coordinated ocean carbon research and observations for the next decade” in 2021.