Feature article

The South Pacific Sea Level and Climate Monitoring Project

Australian Marine Science and Technology, National Tidal Facility and Australian Bureau of Meteorology

More than a decade has passed since the South Pacific Sea Level and Climate Monitoring Project began measuring sea level and associated meteorological variables in the region. The Australian-funded project was implemented in 1990 to address concerns raised by Pacific Island Countries about the potential implications of sea level and climate changes resulting from global warming (from enhanced greenhouse gases).

As a result, there is now a network of 12 SEAFRAME (Sea Level Fine Resolution Acoustic Measuring Equipment) gauges linked to 10 Continual Global Positioning Systems (CGPS) providing sea level, meteorological and terrestrial reference data throughout the South Pacific region (Refer to Figure 1). The array has been widely acknowledged as one of the most accurate and reliable sources available for information on sea level and climate change.

Tidal and sea level information produced by the project are already being used to assist the region’s planning and management in the fisheries, water-resources, communication, transport, environment and coastal-development sectors, as well as in navigation and the forecasting of extreme weather conditions.

Shorter-term variations in sea level are a useful indicator. It is important to note, however, that the fluctuations must be interpreted with caution (Refere to Figure 2). Observed variations in sea level include natural variability, such as effects of atmospheric, oceanographic (for example El Niño) and geological processes. As the sea level record becomes longer, longer-term trend estimates for sea levels at each gauge will become possible. At least 20 years of data will be required for the project to begin to observe any global warming signal (accelerated sea level rise) from background variability. In fact, the Intergovernmental Panel on Climate Change (IPCC) uses as a benchmark a record of at least 50 years to establish long-term trends in sea level.

The long-term results of the project will give the region and their governments a greater understanding of the potential scale and implications of changing sea levels, climate change and variability induced by global warming.

For Further Information contact: Communications Officer, AMSAT, P O Box 17955, Suva, Fiji. Phone or Fax: +6793304003 or Email: [email protected]

Figure 1. Seaframe monitoring station.

Figure 2. The net relative sea level trend in mm/year after subtracting the effects of the vertical movement of the platform and the inverse barometric pressure effect utilising all the data collected since the start of the project up to the end of April 2004.