CLIVAR/CliC/SCAR Southern Ocean Region Implementation Panel Kevin Speer; Matthew England, co-Chairs –CLIVAR IPO Officer Catherine Beswick –SCAR liaison Mike Sparrow Panel Members: Rintoul Stephen Fukamachi Yasushi Goosse Hugues Lovenduski Nicole Marshall Gareth Martinson Douglas Naveira Garabato Alberto Speich Sabrina Thompson David Orsi Alex, Fahrbach Eberhard ex-officio Southern Ocean region serves as a link between ozone depletion (WMO) and carbon cycle (IPCC)

Role of the Southern Ocean in the Earth system The Southern Ocean: Acts as a valve controlling exchange between the surface and the deep ocean; Stores more heat and anthropogenic carbon than any other latitude band and is the primary return path for nutrients; Influences rate of mass loss by the Antarctic ice sheet and therefore the rate of sea-level rise; Is home to unique ecosystems + biodiversity, potentially vulnerable to environmental change. CLIVAR/CliC/SCAR Southern Ocean Region

ARGO: A revolution for the SO starting in 2004 CLIVAR/CliC/SCAR Southern Ocean Region

The Southern Ocean: a particularly dynamical active ocean that continuosly interact with the atmosphere CLIVAR/CliC/SCAR Southern Ocean Region

Science Highlight: Eddy saturation in a QG eddy-resolving model wind ACC transport ~ constant EKE increases CLIVAR/CliC/SCAR Southern Ocean Region

Science Highlight: SO versus the Tropical and NH oceans HEAT CONTENT ANOMALY FRESH WATER VOLUME ANOMALY von Schukman et al. in prep. CLIVAR/CliC/SCAR Southern Ocean Region

Purkey and Johnson, 2011 Science Highlight: Bottom waters changes CLIVAR/CliC/SCAR Southern Ocean Region

undersaturation (blue) by 2030? Aragonite Pteropod: a major food source may start to dissolve Orr et al. (2005) ppm Aragonite CO2 OCMIP-2 modeling Aragonite % saturation Acidification near tipping point? Science Highlight: Southern Ocean still a sink CO2 fluxes weakening as SAM changes?

Imperatives ABSOLUTE need to maintain ARGO (full water column depth hydrographic, and extend sampling or observational techniques to the under-ice-covered ocean, up to the ice shelf grounding line) The Southern Ocean appears to be eddy saturated but we don’t understand the role of eddies with respect to transport and mixing (the IPCC models are not eddy resolving so crucial to address this effect) VITAL to address the gap in estimates of air-sea fluxes of heat and moisture, CO2, wind stress, and boundary layer parameterization near continent Broader evaluation of the impact of acidification and the ecosystem response More accurate diagnoses of the freshwater and moisture transfers among the coupled ocean-ice-atmosphere system, and associated feedbacks Need of sub-ice observations CLIVAR/CliC/SCAR Southern Ocean Region

Frontiers Role of the Southern Ocean in the carbon cycle What does ozone recovery portend for Southern Hemisphere climate and the carbon cycle? What is the future of Antarctic ice? Key for albedo, surface heat flux feedbacks and ice shelves (sea-level). Improve models of ocean upwelling, overturning, and interaction with the shelf What is the impact of acidification? Carry out reanalyses using coupled models with biochemical representations of the carbon cycle: syntheses of ocean/ice/atmosphere data and models What is the future of the Antarctic continental margin? Evaluation and improvement of Earth system models in the high latitudes of the Southern Hemisphere, including runoff from ice shelf lakes CLIVAR/CliC/SCAR Southern Ocean Region

Recent panel activities Panel meeting in Southampton Jun 2010 hosted by the National Oceanography Centre Participation in IPY (CASO, SASSI) New membership (N. Lovenduski for the carbon community) Southern Ocean Vision Document finalized SOOS Design Plan Initiation of a common process study plan with the carbon community CLIVAR/CliC/SCAR Southern Ocean Region

Observing System Issues and Challenges and the development of the SOOS The Southern Ocean Observing System Design and implementation of an observing system that encompasses physical, biogeochemical and ecological processes is therefore a formidable challenge Requires multiple nation and agency involvement since the region is vast, remote and logistically difficult to access and thus is one of the least sampled regions on Earth Observing gaps? Ecosystem monitoring on Argo profiling CO2 gas fluxes Must expand ocean coverage within sea-ice zone Must include atmospheric boundary layer Must include ice interaction regions International SOOS office to carry forward this work CLIVAR/CliC/SCAR Southern Ocean Region

A Southern Ocean Observing System – SOOS

SAMOC – South Atlantic MOC Pilot Array ( ) SAMBA SAMOC Array ( ) Argentina Brazil France Germany NSF, NOAA Russia South Africa

Major plans and activities Review membership and set direction: emphasize modeling the ocean/atmosphere/ice system and process studies Publication of the final SOOS design plan 2011 Develop a review paper on the state of southern climate system (underway with panel co-authors) Work with CliC (co-chair Tony Worby) to develop a freshwater flux estimate and evaluation for the Southern Ocean WRCP Open Science Conference : poster session Panel meeting Boulder CO October 2011 CLIVAR/CliC/SCAR Southern Ocean Region

Activities relating to Southern Ocean modeling issues Development of Southern Ocean metrics to test model skill Provision of latest information on poorly constrained model parameters (Kv, Kappa, etc.) Process studies – to inform on missing physics Observation programmes to bridge data-model gaps CLIVAR/CliC/SCAR Southern Ocean Region