The Antarctic sea-ice zone is an important driver and indicator of global climate processes – its annual freezing and melting is considered to be one of the largest seasonal cycles on Earth. Antarctic sea-ice extent generally reaches its annual maximum during September. SIPEX 2012 will deploy around the time of maximum ice extent to enable the investigation of the sea-ice cover during early austral spring.
Scientists will use an instrumented helicopter (including high-resolution aerial photography, scanning LiDAR and microwave radiometer) to determine snow and ice thickness over regional scales. They will also measure sea-ice motion and deformation to understand the effect of ocean currents and wind on sea ice.
An Autonomous Underwater Vehicle will be operated in partnership with the Woods Hole Oceanographic Institution in the United States. The AUV, fitted with an upward-looking sonar, will measure the draft of sea ice floes. These measurements will be complemented by airborne sea-ice surface elevation and in-situ ice coring surveys to improve estimates of ice thickness and total sea-ice volume.
A Remotely Operated Vehicle (ROV) will be driven very close to the subsurface of the ice to measure optical properties to estimate the amount of ice algae as well as filming the under-ice krill population. This will help scientists to understand the relationships between sea ice, ice algae and krill. More sub-ice samples will be collected by suction pumps and nets and will be used for physiological experiments with krill.
Bio-geochemists and ecologists will be working towards a better understanding of the highly complex relationships between sea ice and snow cover physical properties, nutrients and the productivity of the sea-ice zone. Microscopic algae associated with sea ice are an important food source for Antarctic krill, a key species in Southern Ocean food web and important food source for penguins, seals and whales.
Other science projects to be undertaken during the voyage include studies of
- snow cover on ice floes
- sea ice thickness and deformation processes
- the effects of waves in the sea ice zone on sea ice floe size
- the physical properties of ice and snow, such as crystal structure, temperature and salinity
- the exchange of climate sensitive gases carbon dioxide, methane and dimethylsulfide, between the sea ice and the atmosphere
- the distribution and productivity of sea ice algae and phytoplankton
- the relationship between the physical sea ice environment and the abundance, physiology and condition of Antarctic krill.
For more detailed description of each project, follow the links in the project lists (right).