Tech

January 29, 2014

NASA radar maps winter pace of Iceland’s glaciers

This photo shows a small part of the Hofsjökull ice cap in Iceland, which encompasses several glaciers. The fan at upper left is part of a glacier called Múlajökull.

A high-precision NASA radar instrument left Southern California for Iceland today on a NASA research aircraft to create detailed maps of how glaciers move in the dead of winter.

This will help scientists better understand some of the most basic processes involved in melting glaciers, which are major contributors to rising sea levels.

The instrument, developed by NASA’s Jet Propulsion Laboratory, Pasadena, Calif., is carried on NASA’s C-20A research aircraft, which departed NASA’s Dryden Aircraft Operations Facility in Palmdale, Calif. The experiment is led by Mark Simons, a professor of geophysics at the California Institute of Technology in Pasadena, and Brent Minchew, a Caltech graduate student.

Simons and Minchew used the same airborne instrument in June 2012 to map the summer flows of two Icelandic ice caps. The ice caps – large areas of permanent snow and ice cover – encompass multiple glaciers flowing in different directions and at different speeds.

During the 2012 campaign, surface ice on the glaciers was melting under the summer sun. Meltwater that trickles through the body of a glacier down to the bedrock below can influence the speed at which the glacier flows. By mapping the same ice caps in winter, when the surface remains frozen all day, and then comparing the winter and summer velocities, the researchers will be able to isolate the effects of meltwater.

Map of Iceland shows the flight path (red lines) for a single flight to map glacier flow speeds across two ice caps with the UAVSAR instrument. Each five-hour flight will follow this same complicated path for optimal coverage. The ice caps appear in white in the center of the tangled flight lines; Langjökull is west (left) of Hofsjökull. Keflavik International Airport is on the peninsula in the southwest.

“That’s a challenging subject,” said Minchew. “Our understanding of the effects of meltwater on glacier flow is by no means complete. Even the most sophisticated ice sheet models probably are not capturing all of the salient processes.”

Using NASA’s C-20A airborne science aircraft and support crew, the researchers will make four flights from Keflavik International Airport near Reykjavik, Iceland, between Jan. 30 and Feb. 6 during the few Arctic daylight hours. Each flight follows precisely the same complicated path as flown in 2012 (see map). The crisscrossing flight legs allow the JPL-developed instrument, called the Uninhabited Aerial Vehicle Synthetic Aperture Radar, to map the full extent of both ice caps from multiple angles to capture flows in every direction. The movement of the ice between one flight and the next allows scientists to calculate flow speeds.

“The UAVSAR gives us an entire, continuous map of how every place on the ice cap is moving,” Simons said.

The two ice caps, called Hofsjökull and Langjökull, are ideal natural laboratories for this experiment, according to Simons. They’re relatively uncomplicated and small enough that the scientists can readily use the data from these experiments in computer models of glacier flow without requiring a supercomputer. Langjökull, the larger of the two, covers about 360 square miles (950 square kilometers); for comparison, the largest ice cap in Iceland, Vatnajökull, is more than 3,100 square miles.

NASA’s C-20A carrying the JPL-developed UAVSAR synthetic aperture radar banks over Edwards Air Force Base, Calif.

An even stronger motivation, Simons said, is that “we are benefiting from a huge amount of work on these glaciers that’s already been done by a group of internationally recognized glaciologists in Iceland. The glaciers are in their backyard, and they’ve been studying them for years. They’ve already mapped the ice-rock interface at the bottom of the glacier, for example. We’ve had nothing but support and encouragement from them.”




All of this week's top headlines to your email every Friday.


 
 

 

Headlines May 29, 2015

News: U.S. Army chief opens door to embedding U.S. troops with Iraqi forces - After the fall of Ramadi, the Iraqi Security Forces need military and political leadership, Gen. Raymond Odierno says.   Business: No acquisition strategy yet for LCS frigates - Details of the new Littoral Combat Ship frigate program’s acquisition strategy are still being reviewed,...
 
 

News Briefs May 29, 2015

Finnish navy: Underwater intruder possible foreign submarine Finnish military officials say that an underwater object the navy chased last month in territorial waters and dropped several depth charges could have been a foreign submarine. A navy investigation released May 28 says that technical analysis did not provide sufficient proof of the presence of a submarine...
 
 
Lockheed Martin photograph by Chad Bellay

F-16 test pilots hit the ‘road’ to help train USAFE pilots

Air Force photograph by Airman 1st Class Kyla Gifford Three F-16s assigned to Spangdahlem Air Base, Germany, on a refueling mission last year. Two F-16 test pilots from the 416th Flight Test Squadron recently returned from a &#...
 

 
Navy photograph

Its reign in the fleet over, naval Sea King helicopter now rests at Pax Museum

Navy photograph At more than 54 feet in length with a 62-foot rotor diameter, the mighty SH-3A Sea King helicopter sits in its final spot at the Patuxent River Naval Air Museum. Designed as an anti-submarine warfare helicopter,...
 
 
boeing-korea

New Boeing Avionics Facility to enhance ROKAF readiness, affordability

Boeing formally opened a new avionics maintenance and repair center in the Yeongcheon Industry District of Daegu-Gyeongbuk Free Economic Zone May 28. The 10,000 square-foot facility will test and repair aircraft electrical syst...
 
 
Navy photograph by John F. Williams

ONR testing high-speed planing hulls

Navy photograph by John F. Williams A ship hull model attached to a high-speed sled moves through waves at the David Taylor Model Basin at Naval Surface Warfare Center, Carderock, during Office of Naval Research -sponsored rese...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>