Annual report 2005-06.indd - Antarctic Climate and Ecosystems ...

climate variability & changeProgram LeaderDr Steve RintoulCSIRO Marine &Atmospheric ResearchThe Southern Ocean provides a criticallink in the global ocean circulation thatdistributes heat around the Earth, storesheat and carbon in the ocean, providesnutrients to fuel Antarctic ecosystems,and supplies oxygen to the deep ocean.Present climate models indicate that thiscirculation is sensitive to climate change.A change in Southern Ocean currentswould likely have profound impacts onclimate, ocean uptake of carbon dioxideand marine ecosystems both in theSouthern Ocean and globally.By advancing our understanding ofvariability and change in the SouthernOcean, the CVC Program is improvingour ability to simulate and predict theimpact of Southern Ocean processeson climate, sea-level rise, marineecosystems and the marine carbon cycle.More reliable projections of climatevariability and change and their impactswill allow Australia to plan for the futureand minimise the risks of a variable andevolving climate. Specific applicationsof CVC Program research will includeimproved predictions of the status ofSouthern Ocean ecosystems, improvedmarine resource management, marineimpact studies, public good servicessuch as search and rescue, guidance forsafe Antarctic shipping operations, andresearch into global ocean and climatedynamics.Program Objectives• To characterise the variability ofSouthern Ocean currents, sea ice andclimate and to understand their causes.Variability of the physical environment ofthe Southern Ocean influences regional andglobal climate, distributions and productivityof marine organisms, ocean uptake andstorage of CO 2, and the rate and pattern ofsea-level rise. Knowledge of the variabilityof the coupled ocean-atmosphere-icesystem, including understanding of thephysical processes driving the variability, is aprerequisite for the other ACE CRC Programs.• To determine the likelihood and impactof significant changes in the SouthernOcean physical environment. Changessuch as a slow-down in the Southern Oceanoverturning circulation, a decrease in sea-iceextent, or an alteration in circulation patternsin the atmosphere and ocean would havesubstantial impacts on Antarctic ecosystemsand Australian and global climate. We need todetermine the risk of such changes in orderto develop robust management strategiesfor Southern Ocean marine living resourcesand to guide planning for future changes inclimate and their impacts.• To combine state-of-the-art oceanobservations and numerical models toprovide simulations and forecasts ofocean currents and sea ice for SouthernOcean applications. The applicationsinclude ecosystem prediction, marineresource management, marine impactstudies, initial state estimates for climatemodels, public good services such as searchand rescue, guidance for safe Antarcticshipping operations, and research into oceandynamics.Antarctic Climate & Ecosystems CRC - Annual Report 2005-06 19