Archive for October, 2011

SEAT: Satellite Era Accumulation Traverse: When Canada Stands In for Antarctica

October 21st, 2011 by Patrick Lynch

By Summer Ruper

Hello SEAT blog followers. I am Summer Ruper, and I would like to share with you a little bit of the ice coring adventure that begins well before the field team heads to Antarctica. Before we start drilling ice cores in the harsh cold and wind of Antarctica, we have to train our field team on the drill and sampling procedures. To do this, we took a trip to a slightly warmer region with ice: Athabasca Glacier in the Columbia Ice Field. Athabasca Glacier is near the Canadian town of Banff, and is one of the most visited glaciers in the world. It’s a beautiful area, and plenty of ice to play with.

To begin, we must first answer the question: What is an ice core? Simply put, it is a core sample collected from a glacier or ice sheet. But the ice core is not entirely made up of ice; with the snow fall and wind also come dust, salts, and even ash from volcanic eruptions. All of this is contained in the ice cores and provides information about how snowfall, temperature, and winds have changed over time. A lot of important information is buried in the ice and snow on glaciers and ice sheets, but you have to get the ice out in order to get at that information.

Piece of ice with bubbles inside. These bubbles provide information on the composition of the atmosphere at the time they were trapped in the ice.

Piece of ice with bubbles inside. These bubbles provide information on the composition of the atmosphere at the time they were trapped in the ice.

In order to collect the ice cores, we use a specially designed ice core drill. The one we use is called the FELICS, and is designed and manufactured by Felix and Dieter Stampfli in Switzerland. Basically, the drill has a sharp ring on the end that cuts the ice and feeds the core into a one-meter long barrel. We pull the one-meter section up, empty it out of the barrel, and then drill another one-meter ice core from the bottom of the hole. We do this over and over again until we have drilled to a depth of about 20 meters, and have about 20 one-meter long ice cores.

Randy Skinner, Jessica Williams, and BYU students drilling an ice core on Athabasca Glacier.

Randy Skinner, Jessica Williams, and BYU students drilling an ice core on Athabasca Glacier.

On Athabasca Glacier, our field crew learned how to operate the drill, handle the ice cores, and generally deal with problems that might arise. We were also able to show the tourists visiting that glacier how the drill worked, let them see (and taste) the ice, and share a little of our knowledge and excitement about glaciers and the environmental records contained in the ice. We had a lot of fun, and Jessica and Randy are excited to transfer this experience to our work on the Antarctic ice sheet soon.

Summer Rupper showing an ice core to group of tourists on Athabasca Glacier.

Randy Skinner “sharing” an ice core with a budding glaciologist.

In another post, we will show you what we do with the ice cores once they return to the lab and share some of our preliminary results from last year’s ice cores.

Jessica Williams, Randy Skinner, and Summer Rupper look for the “perfect” spot to drill a core.

Jessica Williams, Randy Skinner, and Summer Rupper look for the “perfect” spot to drill a core.

SEAT: Satellite Era Accumulation Traverse: The Road to Antarctica Begins in Kansas

October 12th, 2011 by Patrick Lynch

By Lora Koenig
The last week of September was a busy one for the SEAT radar team. Ludo, Clem and I spent the week at the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center, at the University of Kansas preparing the radars and the radar sled for shipment to Antarctica. (Yes we are shipping our gear a full two months before we will actually arrive. It takes a long time to ship things to Antarctica.) CReSIS is a unique center that specializes in building radars for the snow and ice (cryosphere) community to use. For the educators out there CReSIS has some great resources that can be found here. (Throughout the blog we will try to insert good education links.)

It was a very fun week for us. We got out from behind our computers and spent most of our time in the metal shop or working with the radars. Our goals for the week were to test the radars, put together the sled exactly how it would be in Antarctica and pack up everything for shipping.

Ludovic Brucker with the unassembled pieces of a sled that will carry radars across West Antarctica.

One of our first tasks was to mount the radar antennas on the metal cross bar of the sled. We have to make sure everything is very sturdy because the sled and radars are going to be bounced along behind a snowmobile for 600 kilometers (about 370 miles)!

Being a scientists isn't all science: Clément Miège works in the metal shop to prepare this piece of the sled for mounting an antenna.

The radars we will use on the traverse were designed and built by CReSIS. Aqsa Patel, who is working on her PhD in Electrical Engineering and Computer Science, along with a team of students, built the radars. Aqsa taught Ludo about all of the electronics inside the Digital Acquisition System (DAQ) for the radars.

Aqsa Patel, who helped build the radars, gives Ludovic Brucker some background on all of the electronics inside the Digital Acquisition System (DAQ) for the radars.

The DAQ converts the signal received from the radars into a digital signal that is recorded by the computer. Our team will be all alone once we get into the field so the preparation time with the radars is very important. We can always call Aqsa from Antarctica—she has promised to have her cell phone with her 24 hours a day while we are on the traverse—but if anything breaks we will have to fix it. Hopefully we will never have to have the DAQ open like this again.

We are taking two radars with us, the Ku-band radar and the snow radar. (For those technical readers: Both radars are FMCW radars with the Ku-band radar operating between 12.5 and 15.5 GHz and the Snow radar operating between two and eight GHz. You can read more about the radars here.) These radars peer into the top 20 to 30 meters of the ice sheet, imaging the firn layers under the surface. Firn is snow that has persisted through one melt season. Another way of saying this is: When snow is one year old we call it firn. Firn layers are just like tree rings, counting them will tell you the age of the layer. The image below shows data gathered from the Ku-band radar last season. This type of image is called a radar echogram and is used to trace and count the layers of firn beneath the surface. How many layers can you count? There are over 20 years of accumulation history in the echogram.

How a radar sees snow.

By Thursday we had everything up and running. In the photo below you can see the sled put together. The red line on the laptop screen at left shows the data the radars are gathering of the metal plate placed below the antenna horns. As you can see, Clem’s work in the metal shop was successful and the antennas, horn-shaped objects at the top right of the picture, are solidly attached. The big red box, to the right in the photo, will house the radars for the traverse.

This is not for your day-after-Christmas downhill sledding fun.

And now for a sneak peak into the future, using some pictures from last year.

When the sled and gear finally arrive in Antarctica the package will look like this:

After months of prep and a big airborne assist, the gear will hit the ground.

Do you see the big red radar box?

The sled loaded with the radar in the field will look like this:

Snowboarding isn't only for mountains.

For now the boxes are packed and shipped by truck to Port Hueneme, Cal. From there a boat will take them to New Zealand and a military cargo plane will make the final leg into McMurdo, Antarctica, where we will pick them up again. We pack everything very carefully so it will not break during the shipment. We have two of almost everything from wires to computers to GPS devices. There are no stores in Antarctica and what we ship is what we get for the science instruments. Rule number one for a successful season will be to not break anything! And that starts from time the instruments are put in the box until they arrive back at CReSIS in late Mar., 2012. Though we are prepared to fix things, we are scientists and what we do best is collect and analyze data. We rely on the engineers, like Aqsa, to build and provide us great instruments.

In all we shipped over 1,400 pounds of gear just for the radars. Some of the more interesting things that we packed are density cutters to measure the snow density, an infrared camera to look at snow-grain size, strips of rubber to insulate metal that could cause frost bite, heating pads to warm up the electronics in the morning, kidney belts for protection riding the snowmobiles such long distances, field notebooks, pencils, toolkits and a small stuffed penguin that wanted to make its way to Antarctica for a photo.

In the next post we will tell you about the ice core drill we are sending and how it was tested on glaciers in Canada to make sure it was ready for the Antarctic field work.

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.