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Ice and Snow Dynamics involve interactions of the atmosphere, cryosphere, hydrosphere, and lithosphere. The cryosphere, a term derived from the Greek word kryo for "cold" or "too cold", is the term which collectively describes the portions of the Earth where water is in solid form, including sea ice, lake ice, river ice, snow, glacier ice, glaciers, ice caps, ice sheets, and frozen ground (including permafrost.) The cryosphere is an integral part of the Earth system with important linkages and feedbacks generated through its influence on surface energy and moisture fluxes, clouds, precipitation, hydrology, and atmospheric and oceanic circulation. Subtle changes in ice and snow covered regions are known to be early indicators of and may be precursors to a changing global environment. The mass balance and dynamics of glaciers, ice caps, ice sheets, and changes in global sea level are of particular environmental interest.

The cryosphere, sea ice, glaciers, ice caps, snowpacks and permafrost, are critical components of the global climate system, with complex interactions and feedback mechanisms that affect not only the polar regions, but also the temperate portions of the Earth. Changes in these components are precursors to a changing global environment with poorly known environmental and societal impacts. Remote sensing products that are currently available in the public domain are beginning to provide the polar research community with information useful for examining a variety of climate change issues. However, much of these data are limited in both spatial and temporal resolution. Greater spatial resolution and geodetic precision, accurate ephemeris information, and historical data are needed to accurately assess the response of sea ice, glaciers and snowpacks to already documented changes in climate, which will be used to validate global climate models, thus providing more accurate climate change predictions.

High-resolution remotely sensed data, especially the archived imagery acquired under the MEDEA Program, will provide invaluable and unique insight into many cryospheric processes, which will allow the scientific community to better understand the global climate system. The data collected by these systems over the long-term, at a number of long-term ecological research areas, will help future generations answer questions of critical importance to environmental science and societal needs. The data from these remote sensing platforms, with its high spatial resolution and ability to revisit remote areas, combined with a long time series of high resolution images, offers unique opportunities for detailed studies of sea ice characteristics, glacial wastage and glacier dynamics, and snow pack extent, thickness and hydrology. Hence, the release of these data to the scientific community would be invaluable.