There are very few choke points in the Southern Hemisphere at which to measure the circulation of the Southern Ocean, and the inter-ocean exchange between the Pacific, the Indian and the Atlantic Oceans. The three main choke points are at Drake Passage between Tierra Del Fuego and the Antarctic Peninsula, south of South Africa and south of Tasmania.
The IPEV (Institute Polaire Emile Victor), and its predecessor agency, have been operating a supply service between Hobart and the French Antarctic island base, Dumont D'Urville, which is a research facility in its own right. The 65-metre supply ship L'Astrolabe, also the name of Dumont D'Urville's vessel during his 1840 journey into the Southern Ocean, has been providing this service since 1988 ferrying expeditioners, equipment and supplies for both Dumont D'Urville and Concordia Dome C operations.
The regular summer service along a direct route between Hobart and Dumont D'Urville offered a marvellous opportunity for scientists to measure the upper ocean characteristics on a regular basis, using technology developed in the 1980's and still used around the world on commercial shipping routes as a tool of ocean observation. With few shipping services in the Southern Ocean, l'Astrolabe's Antarctic service has become an integral component of climate and ocean observations.
Four to six supply services are made each summer, starting in October and concluding in early March, giving scientists a unique opportunity to obtain data from the upper one kilometre of the Southern Ocean. Southern Ocean researchers Dr Rosemary Morrow, from the French oceanographic laboratory, LEGOS and Dr Steve Rintoul from the Australian CSIRO, currently lead the program in support of their climate studies.