Posts Tagged ‘ice’

« Older Entries Newer Entries »

SEAT: Satellite Era Accumulation Traverse: How Much Does It Snow In Antarctica?

October 4th, 2011 by Patrick Lynch

By Lora Koenig

Hello!  My name is Lora Koenig and I would like to welcome you to our Satellite Era Accumulation Traverse blog.  I know that is a mouthful so we will call it the SEAT blog. So have a SEAT, grab a hot drink, and enjoy the blog. From now until mid-January, my colleagues and I will tell you about our science and adventures, from preparing our gear in the U.S. to riding snowmobiles across West Antarctica in order to study how much snow falls in Antarctica.  You will hear about our team’s journey to Antarctica, the science we are doing and share in the fun we have while conducting field work in the coldest, driest, remotest and, forgive the pun, coolest continent on Earth.   We are headed to the West Antarctica Ice Sheet, to a place called Byrd Station.

Byrd Station sits amid the vast West Antarctic Ice Sheet, the scientific target of this two-year campaign to study how much snow has fallen there each year in the past thirty years.

I suppose I should start with a short background of why exactly we are headed off to Antarctica and what we plan on doing there.  But first a question: Have you ever wondered how we measure snow fall in Antarctica?   It is actually rather difficult because, quite frankly, there are not a lot of people around with rulers.   In the interior of the ice sheet, where we are headed, the snow falls each year and creates layers like a stack of pancakes — one pancake per year. The best way to measure snowfall, or accumulation, is by using ice cores that drill into the snow.  Think of taking a straw and sticking it into your stack of pancakes and then measuring the thickness of each pancake.  During this project we will be taking ice cores as well as using radars, that image the snow layers between the ice cores to measure accumulation rate, how much snow fell each year, over the past 30 years, the satellite era.  It is our goal to use the data we get from our field-work to be able to better measure accumulation directly from satellites in the future.

Fantastic sundog

The Antarctic sun creates a spectacular "sundog" behind Lora Koenig during her team's 2010 traverse in West Antarctica. The field campaign resumes this fall to study how much snow falls each year on the bottom of the world. Ice crystals in the atmosphere act as a prism to create this halo effect. Credit: Lora Koenig/NASA

That was a short introduction to the science. We will give you many more details as this blog develops between now and the end of the traverse in January 2011.   For now I want to introduce you to the team.   This project is funded by the National Science Foundation and NASA so we have team members from both NASA Goddard Space Flight Center and universities.   The team members  this season include: Jessica Williams, Randy Skinner and Summer Rupper from Brigham Young University; Clément Miège and Rick Forster from the University of Utah; Michelle Koutnik from the University of Copenhagen; and Ludovic Brucker and me, from Goddard Space Flight Center. In the next post, we will tell you about testing the ice core drill in Canada and preparing the radars for their trip to Antarctica. But first, meet the team:

Hi, my name is Jessica Williams and I just started my master’s degree at Brigham Young University in the Department of Geological Sciences.  I am currently working with Dr. Summer Rupper looking at the snow and ice records from the surface of Antarctica. I am excited to go to Antarctica to drill some ice cores to take back to the lab at BYU to study. Using a combination of density, electrical conductivity, and isotope records from the ice cores we will be able to get snow accumulation rates in West Antarctica. In preparation for this trip I went to Switzerland and Canada to practice using the drill and to gain experience living on the ice.

My name is Randy Skinner and I am a geology professor at Brigham Young University in Provo, Utah. On an annual basis I instruct nearly 1,000 students, most in basic geology 101 classes.  In Antarctica I will be involved in helping to obtain ice cores and digging snow pits. The ice cores will penetrate down to a depth of 20 meters. We will drill 10 of these cores while making our traverse of several hundred kilometers in western Antarctica. The cores and information from the snow pits will be used to determine rates of snow accumulation.  I am very excited to be a part of this research, and to bring these experiences back to share with my future students.

Hi! I am Summer Rupper, and I am a professor in the geology department at Brigham Young University, Utah.  My research is largely focused on the interplay between glaciers and climate.  In particular for our work in Antarctica, my students and I are using the physical and chemical properties of ice to reconstruct the past 30-40 years of temperature and snow accumulation rates.  I was in Antarctica last year helping our team drill ice cores for this research.  This year, I, along with my students, will be continuing the processing of those ice cores in our freezer lab at Brigham Young, while the rest of the team heads back to Antarctica to collect more cores.  I am very excited to have such a great team going to Antarctica again this year, and can’t wait to hear all about their adventures upon their safe return.

Camping on the Ice

On Dec. 10, 2010, the science team set up one of four campsites used during the 2010 leg of the two-year campaign. The vastness of West Antarctica makes finding an open camp site rather simple. Credit: Lora Koenig/NASA

My name is Michelle Koutnik and I work at the Center for Ice and Climate at the University of Copenhagen in Denmark.  I grew up in Southern California, but now I enjoy living in Northern Europe.  I was in Antarctica last season as part of this project and I look forward to a second traverse across Central West Antarctica.  I use computer models of ice-sheet flow to understand ice-sheet evolution over tens of thousands of years.  This project is different because we focus on ice-sheet evolution over tens of years.  I have been working on a computer model focused in the region of Antarctica that we will be doing field work — I am excited for a real trip there instead of just a virtual one!  It will be great to face the challenges of the Antarctic environment and also to work with this team to accomplish our goals.

I am Clément Miège, a PhD student in the Department of Geography at the University of Utah. I am originally from France and I am currently working with Dr. Richard Forster on Greenland and Antarctic snow accumulation patterns. This year will be my second Antarctic field season. During this traverse, I will operate 2 high-frequency radars, in order to produce images of internal snow/firn layers. Later, those images will be used, with the help of ice cores, to give us snow accumulation rates. So we will be able to understand 30-40 years of history for this part of the ice sheet. I am very excited to be on this traverse to keep exploring Antarctica and share this extraordinary experience!!

Preparing Core Samples

Michelle Koutnik, of the University of Copenhagen's Center for Ice and Climate, prepared a core of Antarctic ice to be wrapped and put into core tubes for transport back to labs at Brigham Young University in Utah. But first, Koutnik measured the core's length, diameter and weight. Credit: Lora Koenig/NASA

Hi there! I’m Ludovic Brucker, one of the French citizens on the team.  I came to the US in early 2010 after defending my PhD on passive microwave remote sensing of Antarctic snow. I’m currently a scientist at NASA Goddard Earth Sciences Technology and Research (GESTAR) Studies and Investigations, Universities Space Research Association (USRA), Greenbelt, MD.  This season sounds incredibly exciting and I look forward to our deployment on the West Antarctic Ice Sheet to conduct a 400 miles (~650 km) scientific traverse with snow mobiles! After three years studying the evolution of Antarctic snow properties through the use of satellite observations, I’ll now have a chance to see how the snow really looks! I can’t wait to be on the ice and see how correct, or not, my ideas of Antarctica are!

My name is Lora Koenig and I am a physical scientist in the Cryospheric Sciences Branch at NASA’s Goddard Space Flight Center.  I am a remote-sensing glaciologist who uses satellites to monitor the ice sheets and I am always interested in how well measurements from space compare to those taken on the ground. My interest in ground truth data and learning more about ice sheets will take me to Antarctica for a third time this season.   I have always loved snow and ice.  I started skiing in the Pacific Northwest before I started school and my love for being in cold outdoor places continued into graduate school where I studied topics dealing with both seasonal snow and the polar ice sheets.   My expertise is in microwave remote sensing of the ice sheets.


Real-time Observations of Greenland's Under-ice Environment (ROGUE): And This Concludes Phase 1 of Our Program

May 19th, 2011 by Tom Neumann

May 19, 2011

That's all for now! Credit: Nestor Rial

We are now well on our way back home again, with our GPS stations dutifully recording ice motion in our absence. Several of the stations will be visited again this summer, and all will have a visit this fall to freshen them up for winter. It was something of a whirlwind tour, but we managed to get it all done.

The next phase of the project begins in late June, when a new batch of ROGUE team members returns to Ilulissat and the ice sheet to conduct the hot-water drilling phase of the project. Thanks for following us this spring, and stay tuned to this stations for updates as the situation warrants.

Signing Off,
Tom and Matt

ROGUE: Real-time Observations of Greenland’s Under-ice Environment
The goal of the ROGUE project is to examine the nature and cause of short-term ice velocity changes near Swiss Camp, Greenland, by observing interactions between the ice sheet, the atmosphere and the bed.

Real-time Observations of Greenland's Under-ice Environment (ROGUE): Swiss Camp, Our Home Away From Home

May 19th, 2011 by Tom Neumann

May 18, 2011

Map of Greenland, with Swiss Camp region indicated by the box on the left.

When working out on the ice sheet, it is useful to have a base of operations, so as to not have to move your whole camp every day you want to go to a new place.  For our project, Swiss Camp served as our base of operations. Swiss Camp is one of just a handful of semi-permanent bases on the ice sheet (along with Raven, NEEM, and Summit camps). It has been around in various forms for the last 20 years, and has served as a home base for many many research projects.

Swiss Camp tends to be occupied primarily during the month of May, when Koni and his students base their work out of the camp. This year, Matt and I have had the good fortune to work out of Swiss Camp as well. The camp consists of two insulated tents, each about 10 feet wide by 20 feet long, up on a plywood platform. Koni keeps a couple of snowmobiles at the camp (rather than flying them back and forth each season) as well as a supply of fuel and propane. The fuel is for the snowmobiles and generator, while the propane is used for heating and cooking.

The tents consist of several layers of insulating material stretched over a frame of arched steel poles. A propane heater in each keeps the temperature inside comfortable, even when it is cold and snowy outside. One of the tents is set up as a kitchen and dining area, while the other serves as the workshop. Each season additional tents are pitched for each person to sleep in, and lines of cargo stretch out from camp, creating a small town radiating out from the main tents. The camp is typically powered by solar panels and a battery bank, though the storm this year knocked down the solar panels. Koni will no doubt have them up and running again shortly. Duties are shared, with everyone pitching in to help cook (yes, even me!), and keep the camp running. Snow is gathered from upwind of the camp for drinking water, while Koni brings the supply of food for the camp each year.

Swiss Camp sits near the equilibrium line of the ice sheet. This is a line on the ice sheet where the annual snowfall during the cold months is balanced by the amount of melting during the warm months. This means that although Swiss Camp is buried every winter by snowfall, it melts out each summer. Over time, the equilibrium line has increased in elevation as climate has changed, and ice flow has carried the camp downstream. Now the annual melt is greater than the annual snowfall, leaving Swiss Camp perched up on stilts, and the camp must be lowered every few years. The last such change was in 2010, and the next will probably be in 2012.

More ice melts than accumulates each year, leaving Swiss Camp up in the air. The station will need to be lowered again in 2012. The Swiss Camp weather station is evident in the foreground, while the sleeping tents are off to the left. Credit: NASA/Tom Neumann

At the end of a long day of working outside, the red tents of Swiss Camp are always a welcome sight when they come in to view.

Sunrise at Swiss Camp. The small tents are our sleeping quarters, while the cargo line and the snowmobiles are down wind. Credit: NASA/Tom Neumann

ROGUE: Real-time Observations of Greenland’s Under-ice Environment
The goal of the ROGUE project is to examine the nature and cause of short-term ice velocity changes near Swiss Camp, Greenland, by observing interactions between the ice sheet, the atmosphere and the bed.

Real-time Observations of Greenland's Under-ice Environment (ROGUE): Drill, Baby, Drill!

May 19th, 2011 by Matt Hoffman

May 17, 2011

When we arrived at each study site, we began the process of constructing a GPS station. The first step was probing the snow for crevasses before we start unloading heavy equipment from the sled. By mid-summer, this region will all be bare ice but now it is still covered by about a meter of winter snow. Despite the heavy weights of the snowmobile and sled, we were much safer sitting on them than walking around because of their large surface area in contact with the snow. We deliberately chose sites that were less likely to have large crevasses, but we did encounter small cracks at a few sites.

Tom probes the work area for any crevasses hidden under the snow. Credit: NASA/Matt Hoffman

Once we were confident that we had a safe area in which to work, we unloaded the sled and prepared our tools.  We thought carefully about what order we need tools and instruments, especially on windy days, because anything left out for too long is liable to be blown away or buried in drifting snow. On warm, sunny days anything exposed will be wet before long from blowing snow melting on contact with dark surfaces.

Tom, checking the drill hole depth. Drilling proceeds one meter at a time as new flights are added to the auger stem. Credit: NASA/Matt Hoffman

Because the ice surface on this part of the ice sheet melts about 2 meters (6 feet) each summer, we need to install long poles into the ice to keep instruments from melting out and falling over as the surface lowers. We used a cordless drill with an ice auger system to drill holes about 8 meters into the snow and ice. Once the holes were drilled, we couple pipes together to create poles long enough to survive two summers of surface lowering.

Tom coupling pipes together to create a pole on which to mount the station’s solar panel. Credit: NASA/Matt Hoffman

The crux of the operation was rotating the 8-meter (25 feet) poles into vertical position and down into the holes without damaging the poles or ourselves. Once in place, a GPS antenna is mounted atop one pole to measure the motion of a fixed point on the ice sheet. When we return in fall the antenna will be perched well over our heads. A second pole was outfitted with a solar panel on a PVC sleeve that will slide down the pole as the surface lowers.

The final part of the installation involved setting up a weatherproof box to house the batteries and GPS receiver and wiring everything together. The GPS receiver runs on power supplied by large 12V batteries that are charged by the solar panel. We designed the system so that the receiver will continue to collect data for a few weeks should the solar panel be buried in snow or destroyed in a large storm.

Matt, wiring up the electronics as snow falls. Large batteries (below the electronics board) and a solar panel (attached to the white pole) power the yellow GPS receiver. Credit: Craig Childs

Once we made a final check to ensure that everything was connected properly and turned on (an important final step!) we closed and latched the big green box. The system will have to function on its own until we visit in fall. We said goodbye after loading up the sled, and pointed our caravan back towards Swiss Camp.

A finished station collecting data. Hot pink marshmallow bird for scale. Credit: NASA/Matt Hoffman

ROGUE: Real-time Observations of Greenland’s Under-ice Environment
The goal of the ROGUE project is to examine the nature and cause of short-term ice velocity changes near Swiss Camp, Greenland, by observing interactions between the ice sheet, the atmosphere and the bed.

Real-time Observations of Greenland's Under-ice Environment (ROGUE): Our Traveling Roadshow

May 19th, 2011 by Matt Hoffman

May 16, 2011

The team packed and ready to depart for a day’s work. One person drives the snowmobile while the other rides on the sled with the cargo to mitigate the hazard of crevasses. Credit: NASA/Matt Hoffman

Each day we traveled to a new site in the area around Swiss Camp and set up a new GPS station on the ice sheet. We looked a bit like an Arctic version of the Beverly Hillbillies with Tom puttering the snowmobile out of camp pulling a big red sled piled up with boxes, bags, shovels, more boxes, pipes, solar panels, more pipes, and me precariously perched on top of it all. We crawled around at about 10 miles per hour to avoid rattling my teeth too much, especially when the wind has sculpted the blowing snow into crusty dunes called sastrugi. Our commute typically took about an hour which can be relaxing if the snow is soft and the weather is sunny and calm, or exhausting when it is windy and bumpy.

The view from the sled. The area around Swiss Camp is covered by a series of subtle hills and valleys that provide some variety to the commute. Credit: NASA/Matt Hoffman

Because the ice sheet is pretty featureless, we traveled by GPS to locations that we had pre-determined but never visited. These x’s in the snow were chosen to provide information about both local and regional ice motion around our future drill sites. It’s a bit funny to travel to a specific spot on the ground that looks pretty much like every other spot from horizon to horizon. It’s also a bit funny to use a $100 handheld GPS to locate the site to install a high-precision GPS station, but you’ve got to use the right tool for the job.  Handheld GPS navigation revolutionized travel across the flat white terrain of the ice sheet – without it, losing sight of camp from fog or traveling too far could be disastrous.

Even with GPS, traveling across the snow covered ice sheet can be disorienting under heavy cloud cover when the light is flat and the horizon disappears into a monotonous world of white in all directions. In those conditions, bumps in the snow are only apparent after you have driven over them too fast, and it’s really hard to tell how big anything is. One afternoon I was driving home in poor light, and about half way back I swore there was a little bug flying along side of the snowmobile. My initial (perhaps irrational) thought was that a fly had somehow been blown up onto the ice sheet and happened to be going the same way we were going. I was so convinced by what my eyes were telling me that I started to speed up to keep pace with the intrepid little guy who miraculously was cruising along at about 13 mph. After about a minute of this nonsense, my depth perception instantly snapped into place, and I realized that the fly was actually the GPS station we had set out the day before, about a half mile off in the distance. That night after dinner, Tom regaled us with stories of poor light in Antarctica that was so bad that you could hardly tell which way was up or if you were even moving!

Matt captures a picture of the World's Smallest Man! The lack of surface definition makes Matt and his subject appear to be in the same plane. In fact, the subject is actually over 8 feet tall! (no, not really...). Credit: Nestor Rial

We were fortunate on this trip to generally have very good weather. On sunny days, the appearance of the subtle hills and valleys that cover this part of the ice sheet broke up the monotony, and the interplay of the low-angle afternoon sun on the snowdrifts created glittering sculptures of light and shadow that unfolded before us as we drove home.

The landscape we travel through is not completely flat and white -- at least not when the sun is shining. Credit: NASA/Matt Hoffman

ROGUE: Real-time Observations of Greenland’s Under-ice Environment
The goal of the ROGUE project is to examine the nature and cause of short-term ice velocity changes near Swiss Camp, Greenland, by observing interactions between the ice sheet, the atmosphere and the bed.

Notes from the Field