Tag: ice shelf

Rollercoaster of Opportunity

From Kathryn Hansen, NASA’s Earth Science News Team, Goddard Space Flight Center

Nov. 13, 2010

John Sonntag (left), of NASA’s Wallops Flight Facility/URS, and Michael Studinger (right), of NASA’s Goddard Space Flight Center/UMBC, evaluate the Peninsula mission on the fly. Credit: NASA/Kathryn Hansen

PUNTA ARENAS, Chile — Friday evening, IceBridge teams gathered in the hotel conference room to discuss logistics for upcoming flights. First up: weather. The audience watched the animated WRF model, a tool used for flight planning because it tells you what the weather will be like in the next 6-12 hours. On this particular morning, the model showed system after system lined up to pummel Antarctica. “Are we sure this isn’t the WTF model?” a scientists inquired.

Saturday morning, scientist and flight planner John Sonntag arrived at the airport offices with the flight decision. Weather conditions weren’t perfect, but were the best the Antarctic Peninsula had seen in a month. Given that it had been a few days since the last flight and the forecast looked to only worsen in the days ahead, mission planners decided to take the opportunity to fly under the cloud ceiling. The model predicted clear skies below 10,000 feet. “I hope they’re right,” Sonntag said.

The flight planners quickly worked up a modified version of the “Pen 23” flight plan and at 9:23 we took off for the Peninsula.

The DC-8 approaches the Antarctic Peninsula. Credit: NASA/Kathryn Hansen

We flew the planned route backward, hitting northern cloud-free regions first. Heading south, we followed the eastern side the “spine” — the crest of a mountain range that extends down the middle of the Peninsula. Unfortunately for stomachs, the spine influences weather patterns and the east side also happened to be the windy, turbulent side. The DC-8 may need to restock the little white bags!

Stomachs also suffered from the dramatic changes in altitude necessary to collect data. The measurements require a relatively consistent altitude, which can be tricky when accessing a glacier behind a rock cliff. But the pilots deftly handled the 7,000-foot-roller coaster flight line to collect data over targets also surveyed during the 2009 campaign.

Glaciers meander through the rocky terrain of the Antarctic Peninsula (right). Credit: NASA/Kathryn Hansen

Targets flown: Hektoria, Drygalski, Crane, Flask and Leppard. Each of these glaciers drain into the Larsen A and B ice shelves which broke apart in 1995 and 2002, respectively. Attlee, Hermes, Lurabee and Clifford. Each of these glaciers drains into Larsen C, which is still intact.

So what? Like a cork in a bottle, ice sheets can plug the neck of a glacier. Remove that ice shelf and the glacier more freely dumps ice into the ocean. Scientists want to keep an eye on how these glaciers continue to respond years and decades after the loss of the shelves. Crane, for example, which feeds into the remnant of Larsen B, shows little sign of slowing down.

Cruising further south, however, we encountered too many clouds so we cut across to the west side of the spine to check out the Fleming Ice Shelf. Clouds there also proved too dense, however, so we turned north back to Punta Arenas. At 8.4 hours, the modified Pen 23 became the shortest flight of the campaign — to the relief of many yellow-faced passengers.

Welcome to the Start of the Operation IceBridge 2010 Campaign


From: Lora Koenig, IceBridge project scientist, NASA’s Goddard Space Flight Center



Credit: Image is courtesy of Lora Koenig, NASA’s Goddard Space flight Center

Hello, and welcome to the start of the Operation IceBridge Greenland 2010 campaign. Over the next few months we will be blogging about the science, research, aircraft, and day to day activities of our airborne campaign. The NASA DC-8 aircraft is fully loaded in Palmdale, Calif., and will take off late Sunday night to fly scientists, crew and instruments to Thule, Greenland. The DC-8 will stay in Greenland until the end of April at which time the NASA P-3B aircraft will take over for another month of flights monitoring the changes occurring over the Greenland ice sheet and the Arctic sea ice. Hopefully some of you are returning to the blog after our previous Greenland 2009 and Antarctic 2009 campaigns. Please check in often to follow our progress and learn more about our exciting Arctic research.

My name is Lora Koenig and I am a physical scientist in the Cryospheric Sciences Branch at NASA’s Goddard Space Flight center. You may be asking, what is cryospheric science? Well, it is the branch of science that studies the areas of frozen water on Earth. This includes science related to snow, sea ice, ice sheets, glaciers and permafrost. My research is focused on monitoring changes over the Greenland and Antarctic Ice Sheets and for the last five months I have been one of the NASA project scientists in charge of IceBridge. In this blog I will tell you a little about the planning that has gone on behind the scenes for this campaign.

For the last five months, starting while most of the IceBridge team was still in Antarctica, NASA started planning for the Greenland 2010 Campaign. Because the austral (Southern Hemisphere) spring and boreal (Northern Hemisphere) spring are only six months apart the IceBridge team is constantly planning for the next field campaign. Yes, the Antarctic 2010 campaign planning has already started and the DC-8 has yet to take off for Greenland.

What does planning for a major NASA airborne mission entail? Two things: logistics and flight line planning. A team at NASA’s Earth Science Project Office (ESPO) and the aircraft crews have been busily working to ensure that the instruments are ready to be loaded on the plane, flight clearances are in place, hangers are ready and sufficient for the planes to use, hotel reservations are made, airports are open, divert airports are nearby in case of bad weather, cargo is shipped, the science and instruments teams have flight reservations and passports, cold weather gear is assembled, food is available, internet is set up, and the list goes on and on. These behind the scenes logistics and preparation make for a successful field campaign.

While ESPO was dealing with the logistics, the IceBridge science team and I were tasked with planning flight lines. The Greenland ice sheet and the Arctic Ocean are large areas to monitor. Our aircraft cannot fly everywhere so the science community works together to decide where to fly, when to fly, and how often to fly. Flight decisions are made though a consensus process conducted by teleconferences and meetings with groups of scientists who specialize in studying sea ice, the Greenland ice sheet and ice sheet modeling. Most of the scientists are trying to answer one of the following questions: How are changes in the Greenland ice sheet affecting sea level rise? What changes are occurring to the Arctic sea ice extent and thickness? And in the future, what changes should we be preparing for as the Greenland ice sheet and Arctic sea ice cover change?

Each community of scientists requests specific areas where they want data, and each community desires a specific instrument to take their measurements. In many cases there is overlap in flight lines and instruments and in some cases there is not. Throughout this campaign you will hear about specific flights and the scientific reasons they were flown. Some flights will focus on sea ice, others will overfly glaciers that are changing rapidly and some will overfly scientist working on the ground so results can be extrapolated over a larger area. The IceBridge flight plans are designed to meet the needs of many within a limited amount of time. Flight line planning started in January and was just completed last week. John Sonntag, who you are sure to meet later in the campaign, is the master flight line designer and keeps the aircraft on track for making important scientific discoveries.

Well, I hope this gives you a bit of a flavor for the work that has been occurring by computer, phone and desk to get the Greenland 2010 Campaign up and flying. Next stop Thule, Greenland, with a transit flight that — weather dependant — was designed to monitor a small portion of the southeast Alaskan glaciers and the Arctic sea ice on a transect across the Arctic Ocean.

First Flight: Across the Getz Ice Shelf

 

From: Steve Cole, Public Affairs Specialist, NASA Headquarters

 

PUNTA ARENAS, CHILE – The first flight of Operation Ice Bridge was made from the southern tip of South America on Friday, Oct. 16. The primary target was the Getz Ice Shelf along Antarctica’s Amundsen Coast. The DC-8 flew two parallel tracks along the coast, one just offshore over the floating ice shelf, and one just inland. By measuring on either side of the “grounding line” between the floating ice and the ice on land, scientists can determine the rate at which this near-shore part of the ice shelf is melting.

 

This target area was selected from the series of flights planned because weather forecasts showed that this was the only clear area available. The low-altitude Getz grounding line paths would allow for a survey of the bottom topography with the MCoRDS instrument, a search for the presence of under-ice water with the gravimeter, and ice surface topography measurements with the ATM laser instrument.

 

The plane took off at 9:11 a.m. local time with 31 people onboard, including a videographer with the Associated Press. The DC-8 flew at 35,000 feet on the ocean transit to Getz. During this part of the flight, the LVIS laser and the DMS mapping camera made observations of the sea ice. The DC-8 covered 1630 nautical miles before getting to its science targets in Antarctica.

 

The DC-8 descended to about 1500 feet just east of the Scott Peninsula to begin the low-altitude observations. At the end of the flight path over the Getz Ice Shelf, the plane turned out over the sea ice, which was characterized by open water.

 

The DC-8 then flew up the DeVicq Glacier to an elevation of about 5,000 feet. Returning to the onshore survey line, the pilots were able to fly the entire line with clear skies. We completed a total of 3.5 hours of low-level flight. The ATM team reported collecting about 200 million laser measurements during the flight. The DC-8 landed at about 9 pm.  Total flight time: 11 hours, 45 minutes.

 

— Based on reports from Seelye Martin (University of Washington) and James Yungel (NASA Wallops Flight Facility)

 

 

Getz Ice Shelf at low altitude (Photo courtesy Seelye Martin)

 

 

 

Mount Kauffman at the head of the DeViqc glacier (Photo courtesy John Yungel)

 

 

 

Antarctic sea ice from 20,000 feet. (Photo courtesy John Arvesen)

 

ICECAP Investigates East Antarctica

 

From: Kathryn Hansen, Science Writer, NASA’s Earth Science News Team

Operation Ice Bridge scientists and crew completed 21 successful flights over West Antarctica and returned home in time for Thanksgiving. Still flights over the icy continent continue. Scientists with another field campaign — Investigating the Cryospheric Evolution of the Central Antarctic Plate, or simply ICECAP — are making ongoing airborne investigations over East Antarctica.


The ICECAP Casey/DDU survey team at Casey from left to right: Dean Emberley (KBA), Jamin Greenbaum (Texas), Jorge Alvarez (Texas), Andrew Wright (Edinburgh), Duncan Young (Texas), Young Gim (JPL), Dave Meyer (KBA), Noel Paten (AAD), Ray Cameron (KBA); not pictured Glenn Hyland (AAD). Credit: Todor Iolovski (Bureau of Meteorology)


ICECAP, for which NASA’s Ice Bridge is funding some of the flights, is an international collaboration with principal investigators from University of Texas at Austin’s Jackson School of Geosciences, the University of Edinburgh, and the Australian Antarctic Division. The goal is to use airborne instruments to chart ice-buried lowlands, which could show how Earth’s climate changed in the past and how future climate change will affect global sea level.

Where have they flown and what have they observed? ICECAP’s University of Texas researcher Duncan Young provided some updates from the field:

Dec. 8, 2009

Right now we are preparing to begin our shift from McMurdo to Australia’s Casey Station via the joint French-Italian base on top of the ice sheet, Concordia, after completing our ICECAP flights out of McMurdo today with Flight 16, right down the maw of Byrd Glacier. Tomorrow we will use our survey plane to move people and cargo to Concordia, surveying all the way, and then return to McMurdo. On Wednesday we will move the rest of our people using our aircraft all the way to Casey from McMurdo. It is a complex multinational ballet, where the timing of weather at locations over 1,250 miles (2,012 kilometers) apart is critical. Then we will begin our ICECAP/Ice Bridge operations out of Casey Station with our Australian colleagues.

Dec. 22, 2009

Using an upgraded DC-3, we have completed five flights, each about seven hours long out of Casey Station, in addition to the 20 flights we completed out of McMurdo Station. Three of these Casey based flights have flown over 2,330 miles (3,750 kilometers) of ICESat tracks, over the rapidly lowering Totten and Denman Glaciers.


Denman Glacier; Credit: Jamin Greenbaum, University of Texas at Austin


Today we are conducting an ambitious 10-hour flight to finish off our Casey work for this season. We will be flying to Concordia Station in the center of the ice sheet, picking up fuel and base GPS data we have been gathering over the past ten days to help improve our aircraft positions, and thus the surface elevations we have been measuring.

Then we will fly along a ‘tie-line’ to connect several transects we flew last season to the Dome C ice core. By tracking ice layers in the radar data, we have a chance to find where some of the oldest ice in Antarctica might lie, perhaps more than a million years old. This old ice would contain greenhouse gasses from the past, leading to a better understanding of climate change if it is drilled. The aircraft will then return to Casey station along our last targeted ICESat line along Totten Glacier.

After this flight, we plan to move to Dumount d’Urville Station in time for a French Christmas dinner — if the katabatic winds there allow it …

 

A One-Day Tour of the Antarctic Cryosphere

 

From: Michael Studinger, Lamont-Doherty Earth Observatory, co-principal investigator on gravimeter team

 

PUNTA ARENAS, Chile – The weather forecast for our survey area yesterday, Nov. 16, over the Larsen C Ice Shelf predicted excellent conditions. Given the difficult weather situation over the past couple of days, this was a welcome change. After carefully studying satellite images and computer models and talking to the meteorologist at the Punta Arenas airport, we decided to fly NASA’s DC-8 over Antarctica again.

 

The flight took us through an almost complete tour of the Antarctic cryosphere. We followed the flow of ice from the interior all the way to the ocean where it ends up as icebergs and eventually melts. We began our tour by flying over small ice caps on the Antarctic Peninsula. The snow and ice that forms these ice caps eventually flows downhill through steep valleys that are occupied by glaciers or ice streams.

 

 

Glaciers flowing down steep valleys transport ice from the interior of Antarctica to the Larsen Ice Shelf near the coast.

 

 

At one point during the flight I took the seat in the cockpit behind our two pilots to get a better view of the spectacular scenery. We descended into a steep valley that was filled with ice flowing into the remnants of the former Larsen B Ice Shelf that broke apart a few years ago. The ice that’s flowing down through the valleys is pushing the ice in the ice shelves away and eventually huge chunks of ice break off and form icebergs. On the ice shelf the ice goes afloat and forms huge flat surfaces that seem to be endless. Beneath the ice is ocean water. We are here to study how the warm ocean water melts the ice shelf from beneath.

 

 

 

Small caps of stagnant ice cover the summits while the ice in the valley is moving relatively fast towards the coast.

 

 

Our next survey line takes us all the way to the edge of the ice shelf where we can see several of these gigantic icebergs floating in the far distance surrounded by sea ice and pockets of open water. After crisscrossing the part of the Larsen C Ice Shelf that is still intact, we head back up to the crest of the Antarctic Peninsula and repeat our mini-tour through the Antarctic cryosphere on a different survey line.

 

Every time I look out of the window and soak in the spectacular scenery I see an incredibly beautiful but fragile landscape.

 

We fly over the flat and mostly featureless Larsen Ice Shelf. You can see the steep mountains and glaciers in the background.

 

 

We complete our tour of the Antarctic cryosphere at the edge of the Larsen C Ice Shelf where we reach open water and sea ice.

 

 

All photos: Michael Studinger

 

A Challenging Glacier Flight

 

From: Seelye Martin, Chief Scientist, Operation Ice Bridge

PUNTA ARENAS, Chile — Using the first potentially clear day on the Antarctic Peninsula since we began flights in mid-October, we decided to fly on to targets there on Saturday, Oct. 31.

 

The DC-8 flight path took us over ice elevation lines surveyed by the ATM laser instrument in October 2008. The path included tracks over the Fleming Glacier, one to the George V ice shelf and a parallel one over Palmer Land, plus a single pass down Crane Glacier. The purpose of these flights will be to study the glacier response to the collapse of the adjacent ice shelves. There was also a long grounding line flown around the inside of the Larson-C Ice Shelf. This was a challenging flight, with large elevation changes.

 

 

This map of our actual flight lines (in red) shows that at the most southern point or our flight plan we turned early to get out of the clouds.

 

 

About three and a half hours into the flight we flew the survey line down the Fleming Glacier followed by a descent over the Clifford Glacier. We had a beautiful run down Clifford glacier, which was about our steepest descent in the mission. We then headed north over the southern edge of the Larsen-C shelf.

 

Eight hours into the flight we descended over Crane Glacier into Exasperation Inlet, which is next to Cape Disappointment. The DC-8 pilots say we have a little extra time, so we are going to do a run up Atlee Glacier.

 

One of the scientists onboard came by with the observation that the remnant of Larsen-B in Carr Inlet was showing signs of breaking loose. This does appear to be the one part of the continent where climate change is actually visible, particularly in the northern ice shelves and glaciers. The removal of the buttressing effect of the Larsen-B has led to a speedup of the surrounding glaciers. We repeated Atlee Glacier, then overflew Palmer Station. With that we climbed up in altitude and headed back to Punta Arenas.

 

Although we lost the southern end of our flight lines due to clouds, we got all of our northern track. We also took 300 kilometers of track along the grounding line of the Larsen C, covering most of the shelf.

 

This is my last flight report from Antarctica. I’m rotating out and William Krabill of NASA Wallops Flight Facility will continue as Ice Bridge project scientist for the remainder of our Antarctica 2009 mission.

 

A nunatak sticking through cloud deck at the southern end of our traverse.

 

 

 

 

The foot of Crane Glacier, with glacier ice mixed with sea ice to the left, and the glacier to the right. If you look at the rock wall, there is a suggestion of the former height of the glacier and adjacent Larsen B ice shelf. The glacier surface height drop of about 100 meters has been confirmed by repeated laser observations.

 

 

 

Mountains during maneuvering on the Peninsula plateau.