Tag: General

By Nathan Kurtz, NASA’s Goddard Space Flight Center and University of Maryland, Baltimore County

Looking back, I’m extremely happy that my second time on the IceBridge mission to the Antarctic was a much more intense experience than my first. Last year bad weather kept us grounded quite often and I was limited to going on three flights over the vast extent of sea ice that surrounds the continent. But this year we hit the ground running, well, flying I should say. There were many more flights, more thrills, more snow, more ice…or was there more snow and ice? In fact, one of the main goals of the IceBridge project is to find out whether the Antarctic is gaining or losing ice. While some regions are gaining ice and others are losing it, the question remains as to whether the sum of the parts is in balance. More importantly, how will the southern polar ice cover drive and respond to changes in the climate? How will these climate impacts affect humanity?

An apron of sea ice floats in front the Brunt Ice Shelf, seen on the first flight of the Antarctica 2011 campaign. Credit: Michael Studinger/NASA

With these questions in mind the DC-8 airplane used for IceBridge launched tirelessly day after day to provide some answers. The plane was loaded with instruments to get a unique look from the air that we cannot get with our eyes and hands. It’s amazing for me to think about what great things just a bit of electricity powering the scientific instruments can accomplish (not to mention the massive amounts of coffee apparently fueling the instrument operators). Some electricity fed through an antenna mounted on the aircraft wings produces a radar pulse that can tell us how thick the snow is beneath us. Electricity through a different antenna produces a radar pulse that can tell us how thick the ice is. While even more electricity fed other instruments such as the lasers, gravimeter, and the often-times spectacular photography of all the beautiful areas we pass over.

Outcroppings near Marie Byrd Land. Credit: Michael Studinger/NASA

With all that sensitive equipment loaded on the plane our next step was to fly over interesting areas to measure. We started out with flights in the Weddell Sea to measure the thickness of the sea ice surrounding the Antarctic continent. Antarctic sea ice is a fantastic sight to behold as the strong ocean dynamics in the region create a wide variety in the types of structures that we see. Like a snowflake, no two views of the sea ice are ever the same. In some areas the ice is very consolidated with the ice floes constantly crashing into each other and creating human-sized ridges. In other areas the ice has moved apart, exposing the ocean to the cold polar air and creating intricate geometrical structures as the water freezes and gets stirred together by the wind and ocean.

It is freezing and dynamic processes such as these which determines how much sea ice there is surrounding the Antarctic continent. As a scientist, one of my goals is to use the data collected during these flights to determine how the sea ice is changing and if so, what is causing the changes? How will these changes in such a remote area impact the world at large? It is thought that changes in the sea ice cover will have a large impact on the global temperature by changing the amount of solar radiation absorbed by the Earth. But presently it is not well known how changes in the global temperature will affect the Antarctic sea ice cover. While one may expect warmer temperatures to reduce the amount of ice, it is also possible that complex feedback mechanisms between the ocean and atmosphere could cause the Antarctic sea ice cover to increase with a warming climate. Connecting the observations taken during these IceBridge flights to those from satellites over the past decade will be critical to determining what factors have and will play a part in impacting the ice. While it will take some time to understand what the IceBridge measurements are showing us, there are high hopes for learning a great deal from what has been done.

Path of the IceBridge sea ice flight over the Weddell Sea. Credit: Michael Studinger/NASA

While on my previous flights over sea ice with IceBridge we would often fly near the great ice shelves surrounding the Antarctic continent. To me, the great white ice sheets always looked foreboding, as if they were waiting to swallow up the airplane if we dared venture too far into the interior of the continent to spy on its secrets. This year during my first land ice mission to Pine Island Glacier I half-expected something terrible to happen as soon we crossed the threshold from the ocean to the continent. Thankfully, the plane held a steady pace as if it had absolutely no concern for where it was going. In fact, the plane ended up dutifully flying all over the continent carrying me to some of the most remote and hostile environments on the planet. On the way I saw desolate islands buried in ice, giant crevasses, flew perilously close to lonely mountains with peaks just barely reaching up from the 1+ mile thick sheet of ice covering the land, and so much more. But it didn’t seem scary at all, in fact it was quite beautiful! Well, from 1500 ft above the ground everything looked beautiful. At times, the sensors in the plane showed surface temperatures below -50 F and winds blowing at more than 60 mph. Blowing snow was easy to spot with such strong wind. Perhaps not such a cheery and inviting environment to visit, but perched safely on the plane it was easy to appreciate the splendor of the world below. Interestingly, the map display on the plane showed nothing but an ominous black void beyond 80 degrees latitude, the edge of the world apparently. But the mapmakers have it wrong. While the bottom of the world is certainly a vast abyss, it is of white snow and ice rather than a black nothingness.

Given the enormity of the sheet of ice covering Antarctica it’s hard to imagine that changes could also be happening to it. Yet, as I’ve learned many times throughout my experience with IceBridge, it takes sophisticated instruments to learn what is really happening there. With many more flights to go, and countless more hours spent by scientists looking at the instrument data, we will hopefully find out soon enough.

By Michael Studinger, IceBridge Project Scientist, NASA Goddard Space Flight Center

Punta Arenas, Chile – Better understanding of changes that occur in the polar ice sheets and sea ice requires observations over many years. With Operation IceBridge we make sure that there are no gaps in these critical measurements. In particular, we “bridge” the gap in laser altimeter measurements from space between ICESat, which ended in 2009, and the follow-up mission ICESat-2, which will launch in 2016. Using data from these two satellite missions and combining them with our aircraft measurements we will be able to build a time series of measurements that spans 17 years. In order to build long time series we often have to combine measurements from different instruments and satellites and it is important to make sure we calibrate and validate these measurements against each other, which will allow us to detect changes in the polar ice sheets and sea ice. The goal of Thursday’s IceBridge mission into the Weddell Sea was to better understand how radar altimeter measurements from ESA’s CryoSat-2 satellite can be combined with laser altimeter measurements from NASA’s IceBridge satellites. 

Scarred and chiseled sea ice in the Weddell Sea, where the DC-8 followed in CryoSat-2’s tracks on Thursday’s IceBridge flight. The DC-8’s shadow appears as a dark speck in the lower right. Credit: Michael Studinger/NASA

With IceBridge we are in a unique position to answer these questions because we fly both kinds of instruments on the DC-8 aircraft. In order to compare our measurements we have to fly the DC-8 directly beneath the CryoSat-2 satellite and collect data at the same time in the exact same location. It sounds easier than it is. Many things have to come together to make this happen. First, the weather in the Weddell Sea needs to be suitable for our flight. We need a large, cloud-free area beneath us, which is very rare to find. Second, we need the CryoSat-2 spacecraft on an orbit that allows us to take off from Punta Arenas and fly the DC-8 on the satellite ground track at the same time the spacecraft passes overhead. Third, we need this location to be over a certain type of sea ice that is suitable for comparison of the different measurements. Last, but not least, the weather conditions in Punta Arenas have to be suitable for safe takeoff and landing. Today, we were facing very strong winds that have been close to preventing a flight. While we were flying over the Weddell Sea our colleagues informed us that the winds in Punta Arenas had become so strong that the G-V aircraft had to be moved to Puerto Montt because the wind conditions exceeded the safety specifications for safe parking on the ramp for the G-V. All in all, flying an aircraft directly beneath a satellite in one the most remote parts on Earth is far from trivial. Today, everything went well and the DC-8 flew along the CryoSat-2 ground track in the southern Weddell Sea while the spacecraft passed overhead. The ice conditions were just perfect.

After our rendezvous with CryoSat-2 we reversed course on the ground track to fly back on the same line for 130 kilometers. We did repeat measurements over the exact same segment of our survey line over the course of one hour in order to track the drift of the sea ice. Wind and ocean currents move sea ice floes around. We can estimate how fast and in which direction the sea ice is moving by correlating patterns in our data between the three passes. It is very difficult to make these measurements from space.

After reaching the northern end of our survey line we transit back to Punta Arenas, knowing that we accomplished another landmark sea ice mission for Operation IceBridge.

The Dryden-based DC-8 flight crew handles the plane on its first Antarctica 2011 flight. Credit: Michael Studinger/NASA

By Michael Studinger, IceBridge Project Scientist, NASA Goddard Space Flight Center

Punta Arenas, Chile – Today marks a milestone for IceBridge. For the first time, both NSF’s Gulfstream V (G-V) and NASA’s DC-8 aircraft took off from Punta Arenas for science flights over Antarctica. 

The G-V, with NASA’s Land Vegetation and Ice Sensor (LVIS) on board, headed toward Evans Ice Stream, which flows into the southern part of the Ronne Ice Shelf in Antarctica. 

The DC-8, with its suite of IceBridge instruments, headed toward the Weddell Sea to measure the thickness of the sea ice and the snow on top of it along two 1,700-km-long transects that cross the entire Weddell Sea from east to west. It’s like flying from Chicago to Miami and back at 1,500 feet above the ground. This mission is an exact repeat of two missions that we have flown in 2009 and 2010. The goal is to measure how much sea ice is being exported through the “gate” connecting the tip of the Antarctic Peninsula with Cape Norvegia and determine the changes that occur over time. The export of sea ice from this area is a major contributor to the total ice volume exported into the Antarctic Circumpolar Current.

The DC-8 takes in a stunning view of the Brunt Ice Shelf on its first Antarctica 2011 flight. Credit: Michael Studinger/NASA

The Weddell Sea encompasses a large area and the chances of getting such a large area cloud-free are small. We rely on several different weather forecast models, satellite imagery and meteorologists at the Punta Arenas airport to get a picture of the weather conditions in the survey area before the flight. It requires many years of experience to interpret the different pieces of information and make a decision in the morning whether we launch a mission into the Weddell Sea or not. There is not a single weather station in the Weddell Sea or nearby to provide observations we could use to confirm the model predictions. Imagine needing to rely on a weather forecast back at home that has no weather data between Chicago and Miami. During the flight we encountered the expected mix of clouds, fog and sunshine. We often were able to fly below the clouds and continue to collect data. All in all a great start to our Antarctic campaign.

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

On May 5, 2011, IceBridge surveyed the Devon Ice Cap (above) and two glaciers on Bylot Island (below). Credit: NASA/John Sonntag

Thule, Greenland — On May 5, 2011, Operation IceBridge completed its third and final flight in conjunction with an experiment operated by the European Space Agency (ESA).

The experiment, called CryoVEx, is a series of ground-based calibration sites for ESA’s ice-observing satellite, CryoSat-2. IceBridge flights over these calibration sites ultimately are expected to provide data to evaluate and improve remote-sensing measurements.

“The collaboration will also help us to jointly interpret measurements collected from the ground, air and space, advancing our understanding of ice sheets and sea ice, and their response to climate change,” said Michael Studinger, IceBridge project scientist.

The morning of May 5 started like most days in the field with IceBridge – with an early-morning weather brief. Poor weather afflicted most remaining science sites accessible by the P-3 that day, so IceBridge teams looked toward Canada. A phone call to researchers at Summit Camp on Canada’s Devon Ice Cap – the site of the final CryoVEx site – revealed good conditions.

In the Arctic, however, weather can turn on even the best-informed observations and predictions.

Summit Camp on Canada’s Devon Ice Cap is visible from the P-3, which overflew the ground-based calibration site on May 5, 2011. Credit: NASA/Digital Imaging Sensor

“We flew over the camp and the corner reflectors several times,” Studinger wrote in the mission’s situation report. “Conditions changed quickly. On the last flight we could barely see the camp.”

Still, the clouds parted long enough for the Airborne Topographic Mapper (ATM), a laser altimeter that measures surface elevation, to achieve good data from 75 percent of the area surveyed on the Devon Ice Cap.

Weather was more favorable south of Devon Island over Bylot Island, where the P-3 flew a first-time survey of two Bylot glaciers and collected good data over 90 percent of area surveyed. Credit: NASA/Michael Studinger

The campaign’s previous collaboration with CryoVEx included a flight on April 15 over sea ice, and on April 26 over the interior of the Greenland Ice Sheet.

“This has been a great collaboration between ESA and NASA for cryospheric and airborne science, and will no doubt lead to further joint activities in the future,” Studinger said.

From: Lora Koenig, NASA’s Goddard Space Flight Center, Operation IceBridge Deputy Project Scientist

It arrived, finally it arrived! Yes, the new B200 windshield is here and currently being installed. You begin to realize how remote Kangerlussuaq, Greenland, is when you need something. In the United States you can overnight ship almost anything from Chicago style pizza to Memphis ribs to aircraft windows, but not here. Here, in Kangerlussuaq, the only way to get things this time of year is on one plane that arrives from Copenhagen, Denmark, Monday through Friday at 9:30 a.m. local time.

When the B200 windshield cracked on Monday the plane crew immediately ordered a new windshield to be sent from NASA Langley. It was shipped on Tuesday and arrived today. During the time that it took the windshield transit, the B200 plane crew took out the old windshield and prepped the plane for the new one.

I have learned a lot about aircraft windshields the past few days. For instance aircraft windshields are installed using a sealant (a glue to secure the windshield inside a bolted frame). Even though it has warmed up significantly since we first arrived, it’s just 27 F (-3 C) outside. That’s quite balmy compared to the -8 F (-22 C) temperatures of last week, but the windshield sealant needs temperatures around 77 F to cure. The aircraft is in a hanger but it is still too cold to cure quickly. The B200 crew spoke with some of the Air Greenland crew who lent us some Infrared (IR) heating lamps. The IR heating lamps will allow us to install the window and cut the curing time in half so we can get back in the air sooner.

Right now the window is being installed and sealant applied. Overnight, the window will sit under the IR lamps. On Saturday the plane will undergo a test flight with only the pilots onboard to ensure the aircraft is safe. If all goes well by Monday we will be back up and flying the B200, which carries a high-altitude laser altimeter called the Land Vegetation and Ice Sensor (LVIS).

In the meantime the LVIS instrument has been resting but Elvis sightings around Greenland have remained high.

The first Elvis sighting was Rob White (left) from the B200 crew, and the second Elvis sighting was Shane Wake (right), an LVIS instrument operator. 

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

April 8, 2011

Kangerlussuaq, Greenland — Today’s mission was a mix of the exciting and dull – from spectacular scenery over an ice cap, and up some glaciers and over Jakobshavn’s calving front, to the monotonous but scientifically important back-and-forth mapping of Russell glacier. It was essentially a “mop up” mission, combining targets from three separate flight plans.

We starting the day off flying over Sukkertoppen Isflade, our first ice cap of 2011! Flying over the blanket of ice, the scene abruptly ends as ice cascades down steep terrain into an open-water fjord that separates the ice cap from the Greenland Ice Sheet. Ice caps, while separate from the main ice sheet, are also undergoing changes and contribute to sea level rise.

An open-water fjord separates the Sukkertoppen ice cap from the Greenland Ice Sheet. Credit: NASA/Michael Studinger

Continuing south, we flew along several glaciers starting with Taserssuak (not thinning) and later on over Kangiatanunatasermia (thinning). The difference is interesting, as both glaciers are fed by the same fjord system. Scientists want to keep watch over these regions to continue to see how the change is changing.

We flew four glaciers fed by the Nuuk flord system including this glacier with a colorful name, Akugdlerssupsermia. Credit: NASA/Robbie Russell

After hitting some clouds as expected from the morning’s weather brief, we headed back north and reflew the center flow line of Jakobshavn — always spectacular — before flying over Illulisat Isfjord, which was surprisingly free of ice. The reason for the ice-free conditions was unknown to scientists onboard. There could have been fewer calving events, warmer water, or wind patterns that pushed ice out of the area.

“Half of the Illulisat Isfjord was open water with several fishing boats in the area, something I have never seen before,” said Michael Studinger, the mission’s project scientist.

A camera mounted on the belly of the aircraft captured this image of a fishing boat (top) in the Illulisat flord, which was mostly open water with a few visible patches of ice. Credit: NASA/DMS team

Next it was on to Russell Glacier, just outside of our home base, Kangerlussuaq. Back and forth, this was a true “moving the lawn” pattern. I may have even taken a brief nap. But to scientists, this mapping is critical. A radar instrument onboard will get a good look at what’s below all that ice and help scientists better understand how the bedrock influences the flow of glaciers.