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 November 26, 2014

News: When Hagel leaves, new SecDef faces big questions about the military’s future - President Obama’s new pick to run the Pentagon will face a dizzying set of challenges affecting the Defense Department’s mission, budget and culture. Who will be the next Secretary of Defense?- Following the Nov. 24 surprise announcement from the White House, the...
 
 

News Briefs November 26, 2014

Navy to decommission two more ships in Puget Sound The Navy recently decommissioned the guided missile frigate USS Ingraham at Everett, Wash. It will be towed to Bremerton and scrapped. The Daily Herald reports the Navy also plans to decommission another ship at the Everett homeport and also one stationed in Bremerton. Naval Station Everett...
 
 

NASA airborne campaigns tackle climate questions from Africa to Arctic

NASA photograph The DC-8 airborne laboratory is one of several NASA aircraft that will fly in support of five new investigations into how different aspects of the interconnected Earth system influence climate change. NASA photograph The DC-8 airborne laboratory is one of several NASA aircraft that will fly in support of five new investigations into...
 

 
Air Force photograph by Rick Goodfriend

16T Pitch Boom reactivated to support wind tunnel tests

Air Force photograph by Rick Goodfriend The Pitch Boom at the AEDC 16-foot transonic wind tunnel (16T) was recently reactivated. This model support system is used in conjunction with a roll mechanism to provide a combined pitch...
 
 

Northrop Grumman supports U.S. Air Force Minuteman missile test launch

Northrop Grumman recently supported the successful flight testing of the U.S. Air Force’s Minuteman III intercontinental ballistic missile weapon system. The operational flight test was conducted as part of the Air Force Global Strike Command’s Force Development Evaluation Program. This program demonstrates and supports assessment of the accuracy, availability and reliability of the...
 
 
army-detector

Scientists turn handheld JCAD into a dual-use chemical, explosives detector

Scientists at the U.S. Army Edgewood Chemical Biological Center at Aberdeen Proving Ground, Md., proved it is possible to teach an old dog new tricks by adding the ability to detect explosive materials to the Joint Chemical Age...
 




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>