The aim of this ISSI-enabled project is to use Envisat (ASAR) data to derive information on the current state of, and the inherent variability within the Antarctic sea-ice zone. To achieve this we bring together scientists with active Envisat IPY projects with an focus on Antarctic sea-ice characteristics and processes.

The following ESA IPY AOs are joined in this ISSI project:
• Sea-ice motion, deformation, thickness and lead dynamics in the Antarctic
(AO4007, PI: Haas)
• Southern Ocean sea-ice cover: kinematics, thickness, polynyas, and export
(AO4046, PI: Kwok)
• Complete mapping of Antarctic sea-ice dynamics and thickness
(AO4114, PI: Heil)
• Mapping and Monitoring of Circum-Antarctic fast ice.
(AO4123, PI: Massom)


Schedule for the meeting 30 June to 03 July 2008.

Report of the first meeting.


Knowledge of the ice kinematics, ice thickness and their spatio-temporal variability is fundamental to evaluate the state of sea ice within the global climate system. Sea-ice motion and deformation as well as sea-ice thickness quickly respond to environmental changes. Hence, information on their baseline and variability is crucial to assess the climate system.

SAR imagery will provide regular information on the ice drift and deformation at high spatial resolution over large regions. Our proposed ISSI activity will focus on the Antarctic ice zone, a previously sparsely sampled region (i.e. by RADARSAT). Two of the linked proposals (ESA AO4114 and ESA AO4123) will provide baseline snap-shots of circum Antarctic sea-ice properties including ice motion, deformation and thickness (for the pack ice and the fast ice, respectively; thickness information will be derived from coincident ICESat laser altimetry) during three important stages of the seasonal ice evolution: February (minimum extent while capturing perennial ice regions), June (early winter) and October (maximum ice extent). SAR imagery collected for ESA project AO4007 will provide a regional extension to in-situ sea-ice drift, deformation and growth measurements obtained during three Antarctic cruises (two during austral spring 2007, one during austral autumn 2008) and from drifting sea-ice buoys. The satellite data analysis will make a significant contribution to the overall success of these field campaigns. In addition, a ESA project AO4046 addresses high-frequency (sub-daily), high-resolution processes in the Antarctic sea-ice zone, knowledge of which is crucial to derive an estimate of open water within the pack (i.e. cracks or polynyas). The latter, in turn, is crucial to accurately estimate the net regional ice production, which itself is an important parameter within the polar climate system.

ISSI presents an opportunity to join these four ESA International Polar Year investigations. As part of the ISSI activity we aim - at the data level - to streamline data processing procedures as well as the posting of derived sea-ice parameters. Together these four ESA IPY projects cover nearly the full range of state variables of Antarctic sea ice. The interpretation of data from each ESA IPY project will benefit significantly from bringing together all ESA IPY projects on Antarctic sea ice. Joint analysis methods will also be derived as part of the ISSI workshop.