Deep subsurface warming raises Antarctic sea levels, alarms scientists

Alex Zaharov-Reutt
Monday, 18 February 2008 15:06

Science - Climate

The CSIRO advises that some of SURVOSTRAL’s research highlights include:

- The first description of how the Southern Ocean changes with the seasons, with insights into the formation of Southern Ocean water masses involved in the global overturning circulation;

- The first measurements of year-to-year changes in the ACC;

- New insights into the complex frontal structure of the ACC, including a demonstration that movements of the fronts drive changes in sea surface temperature, with possible feedbacks to the atmosphere;

- Temperature measurements revealed that the sea-level rise observed south of the polar fronts is due to deep subsurface warming, possibly linked to large-scale wind shifts;

- Repeated, high-resolution measurements of carbon dioxide and phytoplankton. The simultaneous measurements of physical, chemical and biological distributions collected by the SURVOSTRAL and MINERVE programs are helping to determine how much carbon dioxide is being absorbed by the Southern Ocean, and how this 'sink' may change in the future;

- A comparison of recent phytoplankton observations with measurements from the 1970s have revealed that warm water species are now found further south, consistent with warming of the Southern Ocean during this period.

Participating research agencies are CSIRO's Wealth from Oceans Flagship and the Antarctic Cooperative Research Centre, the French Polar Institute IPEV, the French oceanographic laboratory LEGOS, and the Scripps Institution of Oceanography.

Nearly 40 scientific papers are in press or have been published in the past 10 years that cite or are based directly on results from SURVOSTRAL research. The program links to the recently established Integrated Marine Observing System, based at the University of Tasmania and is partly-funded by the Australian Climate Change Science Program.

The Wealth from Oceans Flagship is part of the National Research Flagships program initiated by CSIRO to provide science-based solutions in response to Australia's major research challenges and opportunities.

Some images of the SURVOSTRAL project can be seen at the CSIRO’s ScienceImage website, while Antarctic ocean current animations can be seen here.