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 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 in sea-ice thickness 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 sea-ice thickness, emerging techniques such as satellite radar and laser altimetry need calibration and validation. During the SIPEX-2 voyage, the following physics projects will be conducted:
- Airborne sea ice surveys: [R] APPLS
- AUV: Autonomous Underwater Vehicle
- Detailed Snow Characterisation
- Ice Floe Survey
- Observing waves in sea ice
- Role of snow distribution processes on Antarctic sea ice mass balance
- Sea Ice Drift and Deformation
- Sea-ice and snow characterisation
- Spectral and broadband albedo of Antarctic sea-ice types
- Transport processes in sea ice