Ocean circulation and water mass production in the Antarctic region are unique owing to the strong influence of sea ice and ice shelves on temperature and salinity and to a virtual absence of geographic obstacles to circulation around the continent. A key ingredient of the global ocean is the very cold, saline water that forms in regions of the Antarctic's continental shelf. This water is supercooled by exposure to ice shelves (floating glacial ice still attached to the land), and its salinity is increased by salt that is expelled from freezing sea water during annual sea ice production. This water flows off the Antarctic continental shelf and into the global ocean as Antarctic Bottom Water, the coldest and saltiest water mass in the deep ocean and a primary driver in global ocean circulation. Elsewhere around Antarctica, relatively warm water masses flow onto the continental shelf and melt the undersides of ice shelves. This feedback between water masses and ice shelves is still not well understood. | Ocean circulation and water mass production in the Antarctic region are unique owing to the strong influence of sea ice and ice shelves on temperature and salinity and to a virtual absence of geographic obstacles to circulation around the continent. A key ingredient of the global ocean is the very cold, saline water that forms in regions of the Antarctic's continental shelf. This water is supercooled by exposure to ice shelves (floating glacial ice still attached to the land), and its salinity is increased by salt that is expelled from freezing sea water during annual sea ice production. This water flows off the Antarctic continental shelf and into the global ocean as Antarctic Bottom Water, the coldest and saltiest water mass in the deep ocean and a primary driver in global ocean circulation. Elsewhere around Antarctica, relatively warm water masses flow onto the continental shelf and melt the undersides of ice shelves. This feedback between water masses and ice shelves is still not well understood. |