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across north america spring has sprung

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as the mercury rises the winter snow

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seems like ancient history

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not so for nasa's operation icebridge

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scientists who continue to brave arctic

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temperatures at thule air base in

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northern greenland

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since mid-march the icebridge dc-8

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aircraft has flown the equivalent of one

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and a half times around the earth

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logging more than 60 000 kilometers and

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100 flight hours

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the purpose of icebridge is to provide

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data about the earth's polar regions

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allowing us to monitor change in ice

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cover

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icebridge scientists accomplish this by

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measuring the ice with a variety of

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instruments aboard the fully equipped

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dc-8 aircraft

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a typical flight day for icebridge

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begins at 6 am the ground and

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maintenance crews meet at the hangar to

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power up the plane and ensure it is a

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once the dc-8 is towed out to the ramp

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the icebridge pilots and team of

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research scientists prepare for takeoff

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throughout each flight scientists manage

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seven state-of-the-art science

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instruments aboard the dc-8

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several instruments such as the airborne

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topographic mapper or atm utilize laser

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altimeter technology to measure the

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surface of the ice

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three radar instruments from university

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of kansas measure the vertical profile

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of the snow and ice the ku band and snow

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radars measure the depth of snow and ice

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on and near the surface

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the multi-channel coherent radar depth

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sounder or m cords can penetrate the

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upper layers of snow and ice to reach

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the bedrock below telling scientists the

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thickness of the ice the digital mapping

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system or dms is essentially two cameras

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mounted on the belly of the plane

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capturing images every 10 seconds while

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the plane is in flight new to icebridge

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and the dc8 this year is columbia

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university's gravimeter the gravimeter

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can distinguish the difference in

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gravity between rock water and ice to

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map what we can't see

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finally the land vegetation and ice

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sensor referred to as elvis is best

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suited for high altitude work

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from thirty thousand feet and higher

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elvis scans a two kilometer wide laser

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swath to provide a comprehensive map of

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perhaps the most impressive piece of

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equipment is the plane itself

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dc8 production was discontinued in the

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early 1970s but nasa continues to

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utilize it for a variety of earth

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science missions like icebridge

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this four-engine workhorse can fly at 40

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000 feet for over 12 hours at a time

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though the aircraft was not originally

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designed for low altitude flying it

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performs beautifully below 1500 feet for

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icebridge instruments

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after a long day of flying the ground

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crew meets the aircraft on the icy

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runway and prepares for another flight

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day

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at the evening debrief researchers and

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crew analyze the forecast for the

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following day and prepare to do it all

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over again

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icebridge is nearing the halfway point

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of the arctic 2010 campaign next week

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the dc-8 will return to dryden flight

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research center in california where it

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will remain until this fall when it

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resumes ice bridge flights over

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antarctica

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for the remainder of the arctic campaign

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in greenland nasa's p3b airplane will

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deploy from wallop's flight facility in

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virginia to sandstorm air base in

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southern greenland

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science instruments aboard the p3b will