This indicator is no longer maintained, and is considered OBSOLETE.
Measurements of sea surface salinity in the Southern Ocean. Measurements are averaged over latitude bands: 40-50 deg S, 50-60 deg S, 60 deg S-continent.
TYPE OF INDICATOR
There are three types of indicators used in this report:
1.Describes the CONDITION of important elements of a system;
2.Show the extent of ... the major PRESSURES exerted on a system;
3.Determine RESPONSES to either condition or changes in the condition of a system.
This indicator is one of: CONDITION
RATIONALE FOR INDICATOR SELECTION
Australian and Antarctic climate and marine living resources are sensitive to the distribution of ocean salinity. Sea surface values are relatively easy to monitor, and therefore can be used as a relevant indicator of the state of the ocean environment.
The information provided by long records of sea surface salinity is needed to detect changes in the Southern Ocean resulting from climate change; to test climate model predictions; to develop an understanding of links between the Ocean and climate variability in Australia; and for sustainable development of marine resources.
DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM
Spatial scale: Southern Ocean: 40 deg S to the Antarctic continent
Frequency: Monthly averages over summer
Measurement technique: Measurements of sea surface salinity from Antarctic supply ships.
Sea surface salinity has not been previously used as a spatially averaged environmental indicator. Some experimentation with past data are required to define the most appropriate averaging strategy.
New technologies like profiling Argo floats need to be exploited to provide better spatial and temporal coverage of salinity in the Southern Ocean.
LINKS TO OTHER INDICATORS
Sea surface temperature
Sea ice extent and concentration