This ACE research project focuses on how the Antarctic sea ice will respond to changes in climate and in turn what impact these changes will have on the climate system. We also investigate how these changes will impact on marine ecosystems.
Photo: Ice Floes
Antarctic sea ice covers a vast area of the Southern Ocean and is one of the most dynamic environments on the planet. The seasonal sea ice zone over which sea ice advances and retreats each year is about 30%, or approximately 14 million km2 of the Southern Ocean, reaching its maximum extent in September-October. Sea ice is a key factor in ocean-atmosphere interactions, global ocean circulation, and through the ice-albedo feedback mechanism an integral part of Earth’s climate system. It is also a dominant seasonal force in marine ecosystems.
While sea ice extent can be routinely measured from satellites, there are no data available to detect change in sea ice thickness and changes could currently be going unnoticed. During the satellite era (1979-present), no significant net reduction in Antarctic sea ice extent has been measured, although there are significant reductions around the Antarctic Peninsula with compensating increases elsewhere. Changes in Antarctic sea ice extent are predicted under future climate change scenarios, although models for the 21st century show wide variability with a 25-40% decrease predicted. In relation to thickness, emerging techniques such as satellite radar and laser altimetry need calibration and validation. Around the coast of Antarctica, sea ice may be fastened to the shore or to grounded icebergs and remain immobile as a continuous sheet. The properties and extent of this land-fast ice, which is known to be an important habitat for penguins and seals, are poorly understood and are also a subject of ACE research.
Photo: Remotely Operated Vehicle
ACE research in the sea ice zone will use sophisticated data collection techniques (such as Remotely Operated Vehicles) to measure sea ice thickness, extent and physical properties essential to calibrate and validate satellite observations. These in situ observations will be combined with spatial and statistical modelling. The results will contribute to improved parameterisation of sea ice processes in climate models and reduced uncertainty in predictions. We will also improve the measurement capability of coupled physical-biological processes in the sea ice zone, and determine the ecosystem impacts of predicted changes in Antarctic sea ice by evaluating linkages between ocean primary productivity and the structure and dynamics of the sea ice zone and the marine food web.
Projects and project leaders
- The Role of Antarctic Sea Ice in the Climate System: Dr Rob Massom