Southern Ocean Observing System (SOOS): Rationale and strategy for sustained observations of the Southern Ocean
Prepared by: The SCAR/SCOR Expert Group on Oceanography and the CLIVAR/CliC/SCAR Southern Ocean Panel and submitted to OceanObs09 (http://www.oceanobs09.net/) as a Community White Paper for discussion.
Lead author: Steve Rintoul, CSIRO, Hobart, Tasmania, Australia
Contributing authors:
Kevin Speer, Eileen Hofmann, Mike Sparrow, Mike Meredith, Eberhard Fahrbach, Colin Summerhayes, Anthony Worby, Matthew England, Richard Bellerby, Taco de Bruin, Alberto Naveira Garabato, Graham Hosie, Keith Alverson, Sabrina Speich, Dan Costa, Julie Hall, Mark Hindell, Hyoung Chul Shin, Vladimir Ryabinin, Sergei Gladyshev, Kate Stansfield
Abstract:
By connecting the ocean basins and the upper and lower limbs of the ocean overturning circulation, the Southern Ocean plays a critical role in the global ocean circulation, biogeochemical cycles and climate. Feedbacks involving ocean circulation, sea ice, ice shelves and the carbon cycle have the potential to significantly affect the rate of future climate change and sea-level rise, but remain poorly understood. Limited observations suggest the Southern Ocean is 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 Southern Ocean, while the ability of the region to continue to absorb CO2 is a topic of active debate; and there are indications of ecosystem changes. However, the short and incomplete nature of existing time series means that the causes and consequences of observed changes are difficult to assess. Sustained, multi-disciplinary observations are required to detect, interpret and respond to change. Advances in technology and understanding mean that it is now feasible to design and implement a Southern Ocean Observing System (SOOS) to meet this need. SOOS will provide the long-term measurements required to improve understanding of climate change and variability, biogeochemical cycles and the coupling between climate and marine ecosytems. The paper reviews recent progress in understanding the role of the Southern Ocean in the climate system and biogeochemical cycles, summarises the scientific rationale and societal need for sustained Southern Ocean observations, and presents an initial design for SOOS.
