Brian Dunbar
Headquarters, Washington, DC, May 12, 1995
(Phone: 202/358-1547)
Keith Koehler
Wallops Flight Facility, Wallops Island,
VA(Phone: 804/824-1579)
RELEASE: 95-67
NASA and university researchers will conduct ice mapping studies over Northeastern Canada and Greenland that they hope will yield valuable data on the potential effects of global climate change.
"The three-week campaign, which begins May 15, will provide an accurate set of measurements of the ice sheets and glaciers covering two islands in Canada and various areas of Greenland," said Bill Krabill, principal investigator from the NASA Goddard Space Flight Center's Wallops Flight Facility, Wallops Island, VA.
This will be the fifth mission since 1991 that NASA and university researchers have conducted measurements from aircraft and on the ground to provide data on the ice sheets.
The baseline measurements help scientists better understand glacial changes that may be due to global climate change, Krabill said. Some computer models show that increased global temperatures would partially melt polar ice sheets and raise sea levels. Other models show that rising temperatures would stimulate increased precipitation that would, in turn, increase the size of the ice sheets.
It has been estimated that a 10-inch (25-centimeter) decrease in the average height of the central Greenland ice sheet would result in a 0.04-inch (1-millimeter) increase in sea level of the world's oceans.
Recent ice elevation measurements taken from instruments on NASA aircraft were compared to surface measurements taken in 1980. This comparison showed that there has been a 6-foot (2-meter) increase in the ice elevation on the southwest slope of Greenland near the coast. However, other areas, such as the middle of the ice sheet, are stable.
During the May mission, researchers will fly over Greenland and Canada's Ellesmere Island and Baffin Island. Krabill said the Canadian sites were selected for mapping because minor ice caps may react more quickly to global climate changes than do larger ice caps like those in Greenland.
The researchers will use instruments aboard two planes, complemented by ground observations. A P-3B Orion aircraft from Wallops will use a laser-ranging system to measure the elevations of the glacier surface. The instrument, called the Airborne Topographic Mapper (ATM), will scan an area 459-feet (140-meters) wide immediately below the aircraft. The ATM measures the elevations of the glacial surface to within an accuracy of 4 inches (10 centimeters), Krabill said.
Other instruments on the aircraft will include a Wallops' profiling laser system and an ice-penetrating radar from the University of Kansas in Lawrence to measure ice thickness.
NASA's DC-8 will fly from Ames Research Center, Mountain View, CA, to Greenland to take part in the mission. The DC-8 will carry 29 mission scientists, instrument operators and crew members. Its primary payload will be an airborne radar built by NASA's Jet Propulsion Laboratory, Pasadena, CA. Radar measurements will be used to determine the topography of the Greenland ice sheet, and scientists will also attempt to measure the motions of the ice.
Researchers on the ice in Greenland will conduct ground studies beneath the flight path of the aircraft to verify the airborne data. The field team includes researchers from Ohio State University, Columbus, OH; the University of Arizona, Tucson, AZ; and the University of Nebraska, Lincoln, NE.
The ice mapping program is conducted under NASA's Office of Mission to Planet Earth, NASA Headquarters, Washington, DC. Mission to Planet Earth is a long-term, coordinated program to study how our global environment is changing. Using the unique perspective available from space, NASA is observing, monitoring and assessing large-scale environmental processes, with an emphasis on climate change.
- End -
NASA press releases and other information are available automatically by sending an Internet electronic mail message to domo@hq.nasa.gov. In the body of the message (not the subject line) users should type the words "subscribe press-release" (no quotes). The system will reply with a confirmation via E-mail of each subscription. A second automatic message will include additional information on the service.
Questions should be directed to (202) 358-4043.