Southern Ocean Flux Study

Southern Ocean Flux Study
Name	Southern Ocean Flux Study
Caption	Research operations in the Southern Ocean
Location	Southern Ocean
Established	1990s

Southern Ocean Flux Study The Southern Ocean Flux Study was an interdisciplinary field program investigating air–sea exchanges in the Southern Ocean to improve understanding of heat, carbon, and momentum fluxes. Combining shipboard campaigns, autonomous platforms, and satellite retrievals, the program united researchers from institutions such as National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, Scripps Institution of Oceanography, British Antarctic Survey, and Woods Hole Oceanographic Institution. Findings informed parameterizations used in models developed at National Center for Atmospheric Research, European Centre for Medium-Range Weather Forecasts, and Met Office research divisions.

Overview

The study focused on flux processes in the high-latitude belt between the Antarctic Circumpolar Current and the marginal seas like the Weddell Sea, Ross Sea, and Amundsen Sea. Field seasons involved research vessels such as RV Nathaniel B. Palmer, RV Investigator, and RRS James Clark Ross operating alongside platforms like Argo floats, SOCCOM floats, and drifting buoys deployed by Global Drifter Program. Satellite missions integrated into the program included Advanced Very High Resolution Radiometer, QuikSCAT, SeaWiFS, MODIS, GRACE, ICESat, and later CryoSat and Sentinel-3. The study built on prior efforts including the World Ocean Circulation Experiment, Joint Global Ocean Flux Study, and regional campaigns like Southern Ocean Gas Exchange Study.

Objectives and Scientific Questions

Primary objectives targeted quantifying seasonal and synoptic variability of sensible heat, latent heat, radiative fluxes, and air–sea carbon exchange across fronts such as the Polar Front and Subantarctic Front. Key questions probed how mesoscale features like mesoscale eddies and meanders modify exchanges, how sea ice variability in areas near Pine Island Glacier affects fluxes, and how interactions with the Antarctic Circumpolar Wave and El Niño–Southern Oscillation teleconnections modulate regional climate. The study sought to reduce uncertainties affecting coupled models used by the Intergovernmental Panel on Climate Change and regional assessments by organizations including the Scientific Committee on Antarctic Research and the Commission for the Conservation of Antarctic Marine Living Resources.

Methods and Instrumentation

Observational methods combined ship-based meteorological suites, eddy covariance towers, and underway systems for CO2 and pCO2 measurements from laboratories like Lamont–Doherty Earth Observatory and Institute of Ocean Sciences. Autonomous vehicles included Autonomous Underwater Vehicles and gliders maintained by groups such as Scripps Institution of Oceanography and Monterey Bay Aquarium Research Institute. Instrumentation encompassed eddy covariance sensors from vendors used in projects at National Renewable Energy Laboratory, intercalibrated with trace gas analyzers developed at Max Planck Institute for Biogeochemistry and CSIRO. Remote sensing retrievals combined microwave radiometers similar to those on Nimbus-7 and scatterometer data from ERS-1 and MetOp satellites. Data assimilation leveraged systems at NOAA Geophysical Fluid Dynamics Laboratory and European Space Agency research centers.

Key Findings and Data Products

The program demonstrated that the Southern Ocean is a disproportionately large sink for anthropogenic carbon dioxide due to enhanced solubility and biological uptake in regions influenced by upwelling and ekman transport, confirming results consistent with analyses by Global Carbon Project and findings reported in Nature and Science. Observations quantified seasonal reversals in air–sea CO2 flux near the Subantarctic Mode Water formation zone and revealed strong coupling between wind stress variability and heat fluxes across the Antarctic Circumpolar Current Front. Data products included gridded flux climatologies, quality-controlled pCO2 time series, and merged satellite–in situ datasets distributed through repositories like Pacific Marine Environmental Laboratory and World Data Center for Climate archives. Results informed parameterizations adopted in climate model intercomparisons organized by Coupled Model Intercomparison Project.

Collaborations and Funding

The study was a multinational collaboration involving universities and agencies such as University of Tasmania, University of Cape Town, Institute of Marine Research (Norway), Geoscience Australia, and Universidad de Buenos Aires. Funding sources included grants from National Science Foundation (United States), European Commission Framework programs, national research councils like the Natural Environment Research Council, and philanthropic support from foundations such as the Gordon and Betty Moore Foundation. Partnerships extended to operational programs run by Australian Antarctic Division, Antarctic New Zealand, and coordination with programs like Southern Ocean Observing System and Global Ocean Observing System.

Impact on Climate Science and Policy

Insights from the program reduced uncertainties in Southern Ocean heat and carbon uptake used in assessments by the Intergovernmental Panel on Climate Change and informed national contributions to United Nations Framework Convention on Climate Change reporting. Enhanced flux estimates influenced projections in coupled models used by World Meteorological Organization initiatives and guided observational priorities for missions by NASA Earth Science and European Space Agency (ESA). The program catalyzed continued international observing efforts such as expansions of SOCCOM and the Southern Ocean Observing System and shaped policy dialogues at forums including Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the Antarctic Treaty Consultative Meeting.

Category:Oceanography Category:Climate science Category:Southern Ocean research