Tag: General

Ice Calves from Russell Glacier

From: Kathryn Hansen, NASA’s Earth Science News Team/Cryosphere Outreach Specialist


On May 14, 2010, scientists working from Kangerlussuaq, Greenland, with NASA’s IceBridge mission observed ice calving from nearby Russell Glacier. Credit: Eric Renaud/Sander Geophysics Ltd.

IceBridge scientists spend many days in flight surveying the snow and ice from above. On research “down days,” some scientists use their day off to take in the sights. On Friday, May 14, a group of scientists with Columbia University’s gravimeter instrument — which measures the shape of seawater-filled cavities at the edge of some major fast-moving major glacier — made the trek out to Russell Glacier. In the right place at the right time, the group witnessed a calving event that sent ice cascading down the glacier’s front.

“I took burst speed photos with my Canon 40D and just kept my finger on the trigger until everything stopped moving,” said Eric Renaud, an electronic technician with Sander Geophysics Ltd. “We were lucky to witness it.”

Read more about the group’s trek in a blog post by Columbia University’s Indrani Das, and watch a time-lapse video of the calving event composed by Renaud.

Notes From the Met Hut

From: Kyle Krabill, ATM Instrument Team Engineer, NASA’s Wallops Flight Facility

During an IceBridge science flight, a GPS instrument onboard collects measurements of the aircraft’s position. Scientists later combine the positional information with other data, such as surface elevation from the Airborne Topographic Mapper (ATM), to create accurate maps of the snow and ice. Kyle Krabill, from NASA’s Wallops Flight Facility, is an engineer with the ATM group. Instead of spending days in the air on the P-3, Krabill works from the ground to make sure the GPS information is as accurate as possible. In his own words, here’s how and why:

The GPS ground station plays an important role in collecting airborne science data. As with all GPS data there are small errors in position and the airplane GPS receivers alone cannot calculate these errors. This is where the ground station comes into play.

The ground station is set up over a fixed position and checked every day before and after the mission for a precise height to the nearest 1/2 millimeter. Knowing the exact position and also knowing that the station does not move during the flight, the data collected here can be overlayed on the plane GPS data and the position errors are canceled out. This cancellation allows for the plane GPS data to have accuracy to within a few centimeters. The ground station must be located near the area where the plane takes data so that they record data from the same set of satellites.

In Kangerlussuaq we are lucky to have access to set up our station in the Danish meteorological building, known locally as the “met hut”. The ground crew — me — has a duty to monitor the station during flight to make sure there is no break in the data due to loss of power or antenna movement.



Kyle Krabill, of NASA’s Wallops Flight Facility, worked in the “met hut” in Kangerlussuaq, Greenland, during the Arctic 2010 IceBridge mission. Credit: NASA/Kathryn Hansen

An Inland Connection?

From: Kathryn Hansen, NASA’s Earth Science News Team/Cryosphere Outreach Specialist

Scientists have long been tracking Greenland’s outlet glaciers, yet aspects of glacier dynamics remain a mystery. One school of thought was that glaciers react to local forces, such as the shape of the terrain below. Then, researchers noticed that glaciers in different regions were all thinning together, implying a connection beyond local influences. Scientists have posed theories about what that connection might be, but the jury is still out.

Recently, the landscape in southeast Greenland has started to change. Helheim Glacer, which was thinning at 20-40 meters per year, slowed dramatically to just 3 meters per year while thinning of the nearby Kangerdlugsuaq also slowed. Further south, two neighboring glaciers showed the opposite trend and started thickening by as much as 14 meters per year. Neighboring glaciers behaving in similar ways implies a connection, but what exactly?

The IceBridge flight on May 12 will help scientists learn how changes to outlet glaciers affect the ice sheet inland. Instruments on the P-3 surveyed in detail three southeast glaciers: Fridtjof-Nansen, Mogens North and Mogens South. Next they flew four long lines mapping changes near the ocean and up to 60 kilometers inland, capturing the extent, if any, at which thinning near coast reflects on changes to the ice inland. It’s an important connection to make; while the loss of outlet glaciers alone would not contribute much to sea level rise, loss of the ice sheet could have a dramatic impact.

IceBridge crew and researchers board the P-3 on May 12 for a flight to study glaciers and the ice sheet in southeast Greenland. Credit: NASA/Kathryn Hansen


The P-3 flew over areas of sea ice wile mapping glaciers and the flight line closets to the coast. Credit: NASA/Kathryn Hansen

Mountainous terrain along Greenland’s southeast coast led to short-lived periods of turbulence and spectacular scenery. Credit: NASA/Kathryn Hansen

Eyes for Ice: In the Field with Indrani Das

From: Kathryn Hansen, NASA’s Earth Science News Team/Cryosphere Outreach Specialist

KANGERLUSSUAQ – Kangerlussuaq International Science Support is a red, boxy building that doubles as a laboratory and a hotel for polar researchers. Upon my arrival it was quiet, nearly empty. By the end of the week, however, an influx of scientists staging field expeditions quickly filled the kitchen and halls.

Space is limited, so I share a room with Indrani Das, an ice scientist from Columbia University’s Lamont-Doherty Earth Observatory — the only other woman with the IceBridge team here in Kangerlussuaq. She works with the Gravimeter instrument, which measures the shape of seawater-filled cavities at the edge of some major fast-moving major glaciers.

Das, looking out the P-3’s window on the flight to Greenland’s Helheim and Kangerdlussuaq glaciers, has expertise that reveals a world hidden from my untrained eyes — textures in the ice that disclose, generally, how a glacier is moving.

Das wrote about her experience on the flight May 8, sprinkling her narrative with some glacial facts. Read her post here, on the Lamont-Doherty Earth Observatory’s IceBridge blog.

Around Kanger

From: Kathryn Hansen, NASA’s Earth Science News Team/Cryosphere Outreach Specialist

KANGERLUSSUAQ — Science flights from Kangerlussuaq, or “Kanger,” last anywhere form five to eight hours. Then there are the nightly meetings to attend, an aircraft to upkeep, and weather to check. Today’s flight, however, was scrubbed due to weather and ash. What do scientists, engineers and flight crew do when they’re not flying? What’s it like in Kanger?

Kangerlussuaq is nestled at the head of a fjord in western Greenland. The town hosts a commercial airport, which until 1992 was a United States Air Force Base. Now, the town is a hub for tourists and researchers.

Some of the IceBridge researchers and crew are looking forward to the return to Thule, currently planned for May 17. Still, others appreciate the relatively snow-free springtime in Kanger, where you can simply walk to work at the airport, or go for a hike or bike ride.

Here’s a look around town and beyond:

The entirety of Kangerlussuaq, Greenland, can be seen from a nearby hill, just a short drive or afternoon hike away. NASA’s P-3 (top left) waits on the runway for the next science flight. Credit: NASA



Kangerlussuaq International Science Support houses labs, science equipement, and a place for scientists to stay. Credit: NASA

Kyle Krabill, with the ATM instrument group, picks up some Musk Ox steaks from the local butcher shop. Credit: NASA

  There’s even an 18-hole golf course in Kanger, complete with a clubhouse.  Credit: NASA

The P-3 flight crew takes a short drive and hike from Kanger to view Russell Glacier. Credit: NASA


The parents of these dogs are working animals, pulling sleds over the snow and ice. Credit: NASA

Southeast to Southwest: Adapting on the Fly

From: Kathryn Hansen, NASA’s Earth Science News Team/Cryosphere Outreach Specialist

KANGERLUSSUAQ — IceBridge flight planners woke this morning to news that volcanic ash from Iceland had moved over almost half of Greenland, blocking flight lines to survey outlet glaciers along the southeast coast. In response, the team came up with a shortened flight plan that called for limiting the mission to western targets.

First up was Sukkertoppen, or “Sugar Top,” an ice dome just south of Kangerlussuaq. Sukkertoppen, like Geikie Plateau, is isolated and could be undergoing changes different from the rest of the ice sheet. Today’s mission follows two previous surveys of the area (1998 and 2008) giving scientists enough data to tease out trends beyond what could have once been called a seasonal anomaly.

Sukkerttoppen ice dome, south of Kangerlussuaq, Greenland, resembles a vast expanse of powdered sugar. Credit: NASA/Kathryn Hansen

With fuel to spare, the P-3 headed back north to Russell Glacier. That’s where pilot Mike Singer flew back and forth in a “mowing the lawn” grid pattern. Most glaciers surveyed along the coast have been outlet glaciers that calve off into water, but Russell terminates over land. The data is expected to show whether a “grid” pattern improves the models that simulate these land-terminating glaciers.

Melt ponds in spring are found across the surface of Russell Glacier, a land-terminating glacier on the west coast of Greenland. Credit: NASA/Kathryn Hansen

NASA scientist John Sonntag looks at Russell Glacier through one of the P-3’s few windows. Credit: NASA/Kathryn Hansen

The Big Three

From: Kathryn Hansen, NASA’s Earth Science News Team/Cryosphere Outreach Specialist

KANGERLUSSUAQ — The evening before the second science flight, IceBridge scientists Michael Studinger and John Sonntag visited Kangerlussuaq’s weather office — a small building adjacent to the town’s grocery store. Weather can make or break a mission, as clouds interfere with instruments’ ability to map the ice.

This time there was another factor to contend with. Ash from Iceland’s Eyjafjallajokull volcano had made its way over the southeast side of Greenland. Comparing the proposed flight path with the position of ash, IceBridge crew decided the flight was a “go.”

Mission managers selected the Helheim-Kangerd flight plan, which called for mapping two of three glaciers deemed “the big three.” (The third is Jacobshavn, to be surveyed in a separate mission).

Helheim and Kangerdlugssuaq glaciers are quickly accelerating, speeding up ice loss to the ocean. Steep beds and the influence of saltwater working its way under the glaciers are thought to be playing a role. Annual data collected during IceBridge will help scientists maintain a record of the ice loss and learn more about the factors driving the change.

After mapping Kangerdlugssuaq, the P-3 passed over a ground team on an expedition collecting ice cores. The overflight was intentional — multiple sources of data over a single location can prove useful for calibrating data and for research. Similarly, IceBridge flights frequently reexamine tracks previously observed by the ICESat satellite. The ice coring crew was caught on camera (below) by the Digital Mapping System — a digital camera mounted in the underbelly of the P-3.

Isolation

From: Kathryn Hansen, NASA’s Earth Science News Team/Cryosphere Outreach Specialist

KANGERLUSSUAQ — There was a rumor that the flight on Friday, May 10, would be among the most scenic of the 2010 Arctic campaign. The high-priority flight along Greenland’s southeast coast required clear weather for pilots to maneuver along the sinuous glaciers at low altitudes. We were fortunate. The first opportunity to fly from Kangerlussuaq with the P-3 on this Arctic 2010 campaign turned up clear skies and relatively balmy temperatures, and we lifted off for Geikie Plateau shortly after 8 a.m.

Why Geikie? The plateau is “dynamically isolated” from the rest of the ice sheet. That means what happens to the main ice sheet is not necessarily also happening to Geikie. So, IceBridge scientists want to collect Geikie’s vitals — ice thickness, surface elevation, bedrock profile — and compare them with the rest of the ice sheet. “They’re potentially doing very different things, which can tell you something about climate’s impact on the region,” said John Sonntag, Senior Scientist with the ATM laser instrument and IceBridge management team member.

The survey of Geikie Plateau called for about eight hours of total flight time. Credit: NASA/John Sonntag

Observing from one of the P-3’s few windows, I was struck by the scale of the landscape. As we closed in on the southeast coast, the flat barren ice sheet soon mingled with occasional hills and then steep mountains with sharp peaks. Ice appeared to be making its escape, flowing down valleys and merging with the glacial superhighway. Some glaciers terminated in cliffs half a mile high. For others, all that remained were the brown, silty remnants.

Ice works its way down between mountains before joining a larger glacier. Credit: NASA

At the same time that I was making my visual inspection, however, IceBridge instruments were collecting a more scientific type of information. Lasers mapped the surface while radars dove down for a look below. Will scientists find that Geikie indeed acts in isolation? They’ll have a better idea after deciphering and analyzing the data. In the meantime, the IceBridge team is plotting to visit a few other isolated ice sheets throughout the mission — if time and weather permit.

The Multichannel Coherent Radar Depth Sounder instrument shows ice characteristics at depth and also the shape of the bedrock below (thin green line). Credit: NASA

Fasten Your Seat Belts: Mid-Mission Test Flights Complete


From: Michael Studinger, IceBridge project scientist, Goddard Earth Science and Technology Center at the University of Maryland

NASA Wallops Flight Facility, Virginia — During the past week, Operation IceBridge teams have worked at NASA’s Wallops Flight Facility on the eastern shore of Virginia, transferring the science instruments from the DC-8 onto a NASA P-3 Orion aircraft that we will use for the second half of our Greenland campaign. NASA’s fleet of research aircraft allows us to choose the aircraft that is best suited for the science goals that we want to accomplish with IceBridge. We began our work in Greenland with the DC-8 because of its range, load carrying capability, and its ability to fly very high. With the DC-8 we have surveyed the sea ice in the Arctic Ocean and numerous glaciers in northern Greenland. For the second half of the Greenland campaign we will focus on mapping glaciers in southern Greenland using the NASA P-3. The aircraft’s range and maneuverability are ideally suited for low-altitude glacier flying.

The inside of NASA’s P-3 Orion aircraft during installation of Operation IceBridge science instruments at NASA’s Wallops Flight Facility. Credit: Michael Studinger

During the past three months, IceBridge teams from the Center for Remote Sensing of Ice Sheets (CReSIS) at the University of Kansas and Wallops have worked hard to make the impossible possible: designing and manufacturing a complex array of 16 ice-penetrating radar antennas mounted under the wings and the belly of the P-3 and installing and test flying it in only three months! The array of radar antennas is a new development that has never been flown before, allowing us to map heavily crevassed outlet glaciers in unprecedented detail. We will collect several Terabytes of data during each flight that will be processed on a supercomputer at CReSIS when we are back home. The complex array of antennas will allow IceBridge teams to distinguish between radar clutter from surface crevasses and the very weak echo reflected from the base of the glacier of interest. 

NASA’s P-3 research aircraft waits on the ramp at Wallops shortly before taking off for a test flight. The antennas for the ice-penetrating radar system are mounted under the wings. Credit: Michael Studinger

We have now completed a series of mandatory test flights at Wallops to verify the antenna installation and aircraft performance during flight and to check out our science equipment before we leave for Greenland. Research flying has not much in common with everyday air travel. One of the maneuvers that we do during the test flights is to fly the aircraft at a 90° roll angle with the wings perpendicular to the horizon. Fasten your seat belts! You will never experience something like this on a commercial flight. If you do, you might want to consider using a different airline next time.

NASA’s P-3 aircraft during a test flight over Wallops Island, Va. The ice-penetrating radar antennas for Operation IceBridge are mounted under the wings and the belly of the aircraft. Images are courtesy of Rick Hale, CReSIS.

One of the major science goals of Operation IceBridge is to understand the contributions of the Greenland and Antarctic ice sheets to global sea-level rise. During one of the test flights we use the Airborne Topographic Mapper laser system and high resolution aerial photography to map beach erosion on Wallops Island, the location of NASA’s rocket launch facility. Here, at the coast of Wallops Island, rising sea-levels and increased beach erosion are real and need to be considered in long-term planning for the launch facility.

We have now completed all our test flights here at Wallops and are ready to go back to Greenland where we hope to map many of the outlet glaciers and contribute to our understanding and knowledge of future sea-level rise.

Moment of Truth at Summit Camp

IceBridge mission planners plot some flight lines to match the location — and sometimes the timing — of measurements collected on the ground or from satellites. This “ground-truthing” technique helps scientists calibrate and interpret air- or space-based measurements. On April 14, IceBridge flew along a previous track from the Ice, Cloud, and land Elevation Satellite (ICESat), while at the same time scientists at Summit Camp collected ground-based data. Christina Hammock and Sonja Wolter share some images from the event, and provide a look inside the life of a “Summit Camp techie.”

We had been anticipating this flight for almost a month because we were timing some ground-truthing measurements to coordinate with the flight (more below). We had near-daily contact with John Sonntag for a few weeks prior to the flight over Summit Camp. It took a while, but both the weather and the logistics finally came together for the flight on Wednesday, April 14.

Sonja Wolter(right) from Summit Camp in Greenland was working in the field when NASA’s DC-8 passed overhead. Credit: Christina Hammock

Summit Camp is a research station dedicated mainly to atmospheric and climate research. There are only five people on station during the winter months, which is divided into three phases, late August to early November, early November to early February, and early February to late April. During the summer (late April to late August), the station population goes up to 25-50 researchers and support staff (starting a week from today with the arrival of an LC-130 bringing about 25 people – ack!)

Our crew includes a Station Manager — Ken Keenan; a heavy equipment operator — Geoff Miller; a power plant mechanic — Luke Nordby; and the two of us — the Summit science technicians. When we have an involved task like the IceBridge coordination, everyone helps get us out the door.

Gear for the IceBridge and ICESat transect at Summit Station included two snowmobiles, an emergency snow camper, a GPS system and a bamboo pole to make the measurement. Credit: Sonja Wolter

As science techs, we carry out and maintain all the ongoing experiments at or near camp. One of these experiments is the ICESat transect, which is (or was) a ground-truthing measurement for the now-defunct ICESat. The Summit ICESat transect is a zigzagging path of bamboo poles that underlies one of the swaths of the icecap that an ICESat overpass used to include. Once per month, we manually measure the snow depth at the poles and also get exact GPS coordinates at these spots.

To do this, we drive two snowmobiles out and cruise (well, putt putt) along the line poles (at -35 F this week). We don’t know for sure, but we’re guessing the round trip is about 8 miles, and it takes us 2.5 to 3 hours. Although the ICESat instruments are no longer working, we have carried on with the transect measurements to continue the data set for this snow accumulation study. This month’s measurements had the extra bonus of being coordinated with IceBridge for verification of their measurements.

During the winter, the last brush with the outside world (not including the world wide web and telephone, that is) is the Twin Otter flight that comes to pick up the outgoing crew after a week of turnover. So, seeing the NASA DC-8 plane was the first reassurance that people are in fact still out there. Maybe we are geeks, but it was exciting and fun for us to be a part of the IceBridge project.

On April 14, 2010, NASA’s DC-8 flew over Summit Camp, Greenland. Credit: Christina Hammock

When not on the ice, Sonja Wolter works full-time as the operations coordinator for NOAA’s Carbon Cycle/Greenhouse Gases group in Boulder, Colo. Christina Hammock works in Space Science Instrumentation at the Johns Hopkins Applied Physics Lab in Laurel, Md., and formerly worked in the Laboratory for High Energy Astrophysics at NASA’s Goddard Space Flight Center. 

The downward-looking Digital Mapping System camera captured an image of what scientists think is the ground crew from Smmit Camp.Credit: NASA