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 January 23, 2015

News: Two Marines identified in deadly California helo crash - Two Marine Corps officers killed when their helicopter crashed during a training exercise in the Southern California desert were remembered Jan. 25 as talented pilots. Greek F-16 crashes in Spain during NATO exercise - Ten people died Jan. 26 after a Greek air force F-16 jet crashed...
 
 

News Briefs January 26, 2015

Navy wants to increase use of sonar-emitting buoys The U.S. Navy is seeking permits to expand sonar and other training exercises off the Pacific Coast, a proposal raising concerns from animal advocates who say that more sonar-emitting buoys would harm whales. The Navy now wants to deploy up to 720 sonobuoys about 12 miles off...
 
 
Air National Guard photograph by SSgt. Annie Edwards

ANG conducts air refueling training with NATO allies in Germany

Air National Guard photograph by SSgt. Annie Edwards A NATO E-3A AWACS aircraft approaches a Utah Air National Guard KC-135R Stratotanker for air refueling during a training flight over Germany on Jan. 13, 2015. Nearly 30 airme...
 

 
Air Force photograph by SrA. Armando A. Schwier-Morales

Ramstein Airmen train with French air force

Air Force photograph by SrA. Armando A. Schwier-Morales Two U.S. Air Force pilots and a French air force navigator discuss the route to the drop zone during a simulated low-level drop Jan. 21, 2015, at Orleans – Bricy Air...
 
 

Marines receive first F-35C Lightning II carrier variant

The first F-35C Lightning II, carrier variant, for the U.S. Marine Corps touched-down on the flight line at Eglin Air Force Base, Fla., Jan. 13, from the Lockheed Martin plant in Fort Worth, Texas, to begin training in support of carrier-based operations. U.S. Marine Lt. Col. J.T. Ryan, Marine Fighter Attack Squadron 501 detachment commander...
 
 

VA announces single regional framework under MyVA initiative

The Department of Veterans Affairs announced Jan. 26 that it is taking the first steps under the MyVA initiative to realign its many organizational maps into one map with five regions to better serve Veterans. The new regions under the MyVA alignment will allow VA to begin the process of integrating disparate organizational boundaries into...
 




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>