GIIPSY: Global Interagency IPY Polar Snapshot YearThe 2007-2008 International Polar Year (IPY) provides an international framework for improving our understanding of high-latitude climate change and enhancing our skill in predicting world-wide impacts. Recent, well documented observations of the dramatically changing high-latitude components of earth
The Global Interagency IPY Polar Snapshot Year
The Global Interagency IPY Polar Snapshot Year (GIIPSY) is a World Meteorological Organization (WMO)/International Council for Science (ICSU) approved IPY Project (Project #91) whose objective is to obtain high-definition satellite snapshots of the polar regions during 2007-2008. Our primary purpose is to use these snapshots as benchmarks for gauging past and future environmental changes in the polar ice, ocean, and land. In the spirit of IPY, we also seek to secure these data sets as our legacy to the next generations of polar scientists.
GIIPSY comprises a group of polar scientists from around the world who have assembled a consolidated list of thematic objectives that call upon the collective resources of international and national space agencies. Our programmatic goal is to identify ways in which the resources of space-faring countries can be used in such a way as to collect data with which to address these scientific objectives, without putting undo burden on any single organisation. To that end, we seek cooperation in terms of spaceborne instruments, data relay systems, ground segments, processing, and data archiving and distribution capabilities.
A general description of the GIIPSY programme and its current status and progress can be found on-line at http://bprc.osu.edu/rsl/GIIPSY. Detailed scientific driving requirements and objectives for the satellite observations were derived from pre-IPY town hall meetings (e.g. AGU December 2006), discussions with other science planning groups including IGOS (Goodison, 2007, IGOS, 2007), and wide-ranging debate within the GIIPSY science community. The complete set of requirements are documented in subsequent publications and presentations (Jezek and Drinkwater, 2006, Drinkwater et al, 2008) or on the GIIPSY Web site. Together, we have taken the detailed science requirements and distilled them into a set of thematic objectives. Topics range from permafrost to sea ice and include several objectives that would be the first of their kind. In order to fulfil these scientific objectives, carefully coordinated data acquisitions over both the northern and southern hemisphere have to be scheduled using the broad range of available satellite instrument capabilities. This is best achieved using polar-orbiting satellites that routinely acquire image or other instrument data over the high-latitude regions along 14 crossing orbits each day.
Operational meteorological satellites equipped with the AVHRR optical imager such as NOAA-15 and MetOp acquire data which are routinely composited to provide complete polar coverage at intervals of up to a few hours. Such overlapping images acquired by meteorological satellites are used to track large-scale cloud motion, for instance, when the surface is cloud-covered. Meanwhile, other higher resolution satellite optical instruments may be used to capture ice sheet movement in instances when the surface is not obscured by clouds. Optical data are complemented by all-weather, day or night data acquired using satellite microwave radar or radiometers. Regular Arctic and Antarctic mosaics allow regional details of sea-ice conditions to be determined using microwave synthetic aperture radar (SAR) image data, while pairs of high resolution SAR images may be used interferometrically, to reveal streaming ice flow in Greenland or Antarctica.
Finally, the products derived from multi-satellite, multi-frequency satellite data may be plotted on a virtual Earth to fully capture the state of various elements of the cryosphere. Many such products are now routinely available in Google for convenient viewing of current status of the entire Arctic (see: http://www.seaice.dk/damocles) and Antarctic (see: http://www.seaice.dk/polarview/google.s.html) regions.
IPY Space Task Force
Interaction between GIIPSY and the international space agencies is coordinated through the IPY Space Task Group. The Space Task Group (STG) of the Sub-committee on Observations of the ICSU/WMO Joint Committee for the International Polar Year 2007-2008 is the body tasked with addressing how to meet the space observation requirements of IPY. A number of meetings have taken place between the following Space agency members and participating organisations: Agenzie Spaziale Italiana (ASI), China Meteorological Administration (CMA), the Centre National d