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| File photo shows a NASA satellite image from September 16, 2007 and released on September 21, 2007, shows Arctic summer sea ice. Arctic sea ice melted to its lowest level ever this week, shattering a record set in 2005 and continuing a trend spurred by human-caused global warming, scientists said on September 20, 2007. (Xinhua/Reuters File photo) |
LOS ANGELES, March 20 (Xinhua) -- NASA on Sunday kicked off the second year of a mission designed to conduct a airborne survey of the Earth's polar ice.
"The first priority is to survey Arctic sea ice, which reaches its maximum extent each year in March or early April," according to a NASA statement. "High- and low-altitude flights also will survey Greenland's ice sheets and outer glaciers," the statement said.
The mission will be conducted by an aircraft which takes off from the Dryden Aircraft Operations Facility near Palmdale, Southern California later in the day, according to NASA.
NASA called the mission the largest airborne survey ever of the Earth's polar ice.
The DC-8 airborne science laboratory is scheduled to arrive in Greenland on Monday as part of Operation IceBridge.
From there, scientists and flight crews expect to carry out 10- 12 missions over the Arctic over a five week period, recording changes in the extent and thickness of polar ice.
The DC-8 and a smaller aircraft -- a P-3B -- will be equipped with an Airborne Topographic Mapper, which measures changes in the surface elevation of ice by bouncing laser beams from the ground back to the aircraft and converting the readings into elevation maps.
Another laser altimeter -- the Land, Vegetation and Ice Sensor - -is used at higher altitudes and can survey larger areas more quickly, according to NASA.
