Measuring the Changing Thickness of Ice
Ice, in the Polar Regions plays a crucial role in regulating the Earth's climate, but until now it was extremely difficult to gauge the thickness of the ice or measure changes over time. Satellite images provide a good tool to determine the surface area and boundaries, but measuring the thickness could only be accomplished on single points by costly drilling through the ice. A new generation of Earth Observation (EO) satellites, developed by the European Space Agency (ESA), are about to change the way we measure the thickness and changing conditions of the ice.
The Cryosat-2 satellite is the most sophisticated satellite ever developed to study the Earth's ice fields. Cryosat-2 will carry a single payload instrument, a new RADAR-altimeter called SIRAL. The satellite will take 20,000 measurements per second over the next three years with unequalled precision, and be able to detect changes in the thickness of the ice of only a few centimeters.
The Cryosat-2 satellite is set to launch on April 8th, 2010 from the Baikonur Cosmodrome in Kazakhstan.
The speed at which the Arctic ice is melting in recent years has generated concern among scientists and the public. It has become one of the most visible impacts of global warming in the climate change debate.
The SIRAL instrument has been optimised to measure changes in the thickness of both floating sea ice, which can be up to several metres thick, and polar land ice sheets, which in Antarctica can be close to 5 km thick. The mission will deliver data on the rate of change of the ice thickness with an accuracy of within one centimeter.
The Canadian Space Agency (CSA), as a cooperating member of ESA, contributes to the Earth Observation Envelope Programme through which the CryoSat missions are being coordinated. Canadian scientists and researchers will play a key role in this mission by analyzing and validating data captured by the satellite. Their participation is made possible through the partial funding provided by CSA's Government Related Initiative Program (GRIP).
Through the CSA GRIP Program, the Geological Survey of Canada (Natural Resources Canada) is initiating a new project called "Canadian Cryosphere CryoSat Applications" which will develop capacity in the study of cryosphere fluctuations and their impacts on Northern Canada. In support of Canada's Frontier Surveillance Strategy, the project will contribute to policy development; provide technical data; and contribute to the strategic demonstration and operationalization of Cryosat-2.
Canadian scientists leading teams participating in this Earth Observation mission are:
Quantification of the variability between radar-measured snow surface elevation change, actual snow surface elevation change, and ice mass change
Cross-calibration of the CryoSat-2 altimeter over icecaps and ice fields of the Canadian Arctic and Rocky mountains with in-situ geo-positioning
Airborne Laser Terrain Mapping and geophysical snow properties studies validation of CryoSat-2: sea ice thickness, freeboard, and sea surface height.
CryoSat-2 Multi-Surface Validation in Churchill, Manitoba and Hudson Bay
Calibration and Validation of CryoSat-2 data products
Validation of sea-ice thickness data from CryoSat-2 using a fix-mounted helicopter-borne electromagnetic sensor, and upward-looking sonar moorings in Canadian Arctic and Labrador Shelf Regions.
Ice caps and glaciers occupy 150,000 km2 of the Canadian Arctic Islands which, collectively, represents the largest area of land ice outside of the Greenland and Antarctic ice sheets.
Another 50,000 km2 of land ice covers Canada's western and Northern Cordillera. These land ice masses contribute significantly to the change of sea level and flow of rivers.
The thickness and extent of marine ice fields, or sea ice, is also a critical aspect of the functioning of the Arctic marine ecosystem, the global climate system, marine navigation and issues related to sovereignty and protection of the environment.
After the launch of CryoSat-2, the Devon Ice Cap in the Canadian Arctic and the Columbia Ice field in the Canadian Rockies will serve as two glacier calibration/validation sites. The Lincoln and Beaufort Seas will also be used as test sites in the validation of the measurements of marine ice.
For more information on Cryosat-2:
For more information on the GRIP Program: