The Southern Ocean observing system: initial science and implementation strategy

The Southern Ocean provides the principal connection between the Earth’s ocean basins and between the upper and lower layers of the global ocean circulation. As a result, the Southern Ocean strongly influences climate patterns and the cycling of carbon and nutrients. Changes in the Southern Ocean would therefore have global ramifications. Limited observations suggest the Southern Ocean is indeed changing: the region is warming more rapidly than the global ocean average; salinity changes driven by changes in precipitation and ice melt have been observed in both the upper and abyssal ocean; the uptake of carbon by the Southern Ocean has slowed the rate of climate change but increased the acidity of the ocean; and Southern Ocean ecosystems are reacting to changes in the physical and chemical environment. However, the short and incomplete nature of existing time series makes the causes and consequences of observed changes difficult to assess. Sustained, multidisciplinary observations are required to detect, interpret and respond to change.