ECE: Electrical & Computer Engineering
ECE News

Deep Freeze: Space Science takes ECE to Antarctica

Greenland

Earlier in his career, Clauer worked with the magnetometer array in Greenland. This array, along the west coast of Greenland, is equipped with enough stations to allow only a few hundred kilometers between them. Scientists have been collecting and analyzing data from this array for years, and are hoping that the new South Pole array will furnish them with similar data.

Clauer relates one of his favorite experiences from his work in Greenland, when researchers saw small spikes in their data that needed to be explained. Using data from the Greenland magnetometers, they found that all vectors pointed to a single point because a field-aligned current and a radial electric field caused the ionosphere to move in a circle around the current. “I really appreciate clever displays of data; they open your eyes to understand what is happening. It’s rare that you see data come out that looks so perfect.”

South Pole Station

South Pole Station is a permanent research station located in the center of Antarctica, only about 350 meters from the Geographic South Pole. Clauer notes, “it has many scientific applications, including a clean air sector, a dark sector where no lights are allowed, and a seismic research sector.”

With all this research around, finding a location to set up sensors in the surrounding area can be tricky. To get out on the plateau to set up sensors, people and equipment are flown to their site in small planes. “You need good GPS coordinates for each station so that the plane can find it again,” according to Clauer. “We accidentally put one of our stations in the middle of the ski trail, but it wasn’t a problem to move the trail over a bit,” he says.

The only way to access South Pole Station is to take a plane from McMurdo Station, which is located on the coast of Antarctica. There is only one type of plane coming from McMurdo to South Pole Station: a C130, which is a military plane with skis that is mostly for cargo. Five firefighters must be on the runway every time it takes off or lands.

A scientist stands on the raised sensor platform

The research team combated the altitude, long days, and extreme cold weather as they worked to troubleshoot and install data collection stations. The team labored to install and protect their equipment, which was designed to withstand the grueling Antarctic weather.

A Virginia Tech research team is working to understand space weather — from the South Pole. As part of a $2.39 million grant from the National Science Foundation (NSF), the team is deploying seven autonomous data collection stations in Antarctica within the next four years. There are unique difficulties associated with the project, but also a unique payoff: these are measurements that no one has taken before.

Each system is autonomous and designed to operate unattended for at least five years on the east Antarctic plateau. Data are acquired at Virginia Tech in near real time using satellites.

When fully deployed, the chain of data platforms will help with studies of global phenomena from the solar wind/magnetosphere interaction. Specifically, researchers will be able to observe the changes in the electrodynamic circuit formed by the solar wind coupled to both polar ionospheres by magnetic field lines.

The seven stations will be roughly along the 40° magnetic meridian (longitude) — the same magnetic meridian where researchers already have magnetometers in the northern hemisphere along the coast of Greenland. Once they have a similar chain in Antarctica, the team can see how the data from the two hemispheres relate. “We have models of the global magnetosphere, but we’d like to validate those models,” explains Robert Clauer, the ECE professor who heads the team. “Since these are all new measurements, that are coordinated between both Northern and Southern hemispheres, maybe we will see something that lets us understand a new phenomenon.”

There are SuperDARN radars in the South Pole area as well, so scientists can also measure the electric fields over the new platforms. “Eventually,” Clauer says, “we’ll put all the data together to start understanding it, then relate it to the Northern hemisphere.”

This winter, Clauer, with post-doctoral researcher Hyomin Kim and graduate students Joseph Macon and Kshitija Deshpande, traveled to Antarctica to troubleshoot an existing station that had failed and to install two new stations as test systems at the South Pole research station. If the new stations function well for a year, they will be deployed next year to remote locations a few hundred kilometers from the South Pole.

The Stations

Bob Clauer, Kshitija Deshpande, Joseph Macon, and Hyomin Kim stand in front of one of the stations, which is flying a Virginia Tech pennant

The team flew a Virginia Tech pennant at the stations being tested at South Pole. From the left, Bob Clauer, Kshitija Deshpande, Joseph Macon, and Hyomin Kim.

Each platform includes three devices: a fluxgate magnetometer, a search-coil magnetometer, and a dual-frequency GPS receiver. The fluxgate magnetometers measure background magnetic fields, which are associated with electrical currents in the ionosphere, while the search-coil magnetometers specifically measure the changing magnetic fields and low frequency (ULF) waves.

The GPS receivers can measure how a signal changes from movement through the ionosphere, and can calculate the number of electrons that the signal has moved through. This is very new technology, according to Clauer, who calls it risky but very flexible. The GPS receivers were originally designed at Cornell and customized by Brent Ledvina, a former ECE assistant professor, and Todd Humphries from the University of Texas at Austin. “It’s ideal for us to get such a nice instrument tailored to our needs in the polar regions,” Clauer notes.

Because these systems are made for deployment in such a harsh environment as the South Pole, there are some unusual design considerations. The only way to transport the systems in Antarctica is by small aircraft, so weight and size is important. Yet, the systems require enough battery power to operate through the winter.

Design for a Harsh Environment

The super-insulated box that contains the batteries and electronics

The data stations run on standard lead-acid batteries during solar winter.

Clauer explains that it is also important for the systems to be simple and reliable. “Lots of exotic solutions may work, but they are very risky,”he says. “Lead-acid batteries are very robust; they have been around a long time and they work. Solar cells run the system during the summer, lead-acid batteries during the winter.”

The electronics are housed in a super-insulated box, custom-made from vacuum panels for minimal thermal loss. Energy loss from the electronics is sufficient to heat the box, but the Iridium radio and the GPS receiver cannot be operated for long at the same time, or the box becomes too hot. When the outside temperature is around -20° F, the temperature in the box is around 104° F (40° C) and can get up to 80° or 90° C very quickly with both devices running. Clauer, however, isn’t concerned about this. “It’s something we can deal with,” he says.

The Iridium radio transmissions also cause some interference for the GPS receiver. The team is working with positioning the GPS antenna to minimize this interference. “This is a prototype for testing,” Kim explains, “and we’ll debug the problems for a year before we move the systems to actual locations. So it’s not too surprising that we have some small issues to resolve.”

The team built four stations this year. Two are at the South Pole for a year of testing in Antarctic conditions; one is at Ann Arbor, Michigan; and one is at Virginia Tech. If the two stations established this year at the South Pole work reliably, they will be deployed in the field next year and the stations from Ann Arbor and Virginia Tech will go for testing at the South Pole.

Two stations have already been deployed at locations in the field: PG1 and PG2. These stations are based on an earlier model of the platform, and have only one magnetometer each. PG1 was tested at the South Pole for a year before being set up at its location, but PG2 was not tested before deployment and is the one that failed and returned to Virginia Tech. “We think it may be a communication failure,” says Macon, who attempted to fix the station in December.

Macon notes that there will be some difficulties to overcome while setting up the system for testing in Blacksburg. “The platform can’t be set up with liquid precipitation,” he explains, “because it’s designed for dry and cold weather. We have to figure out how to deal with that if we’re going to set it up here in Blacksburg. It will work just fine, but we have to make sure it’s protected for a different environment. There are a lot of wires to be buried in snow, and we can’t do that here. Something might run over it, or some rodent might decide it’s tasty.”

The stations consist of a tower, a main vault for batteries and electronics, and instruments. The tower holds only the solar cells and Iridium radio antennas — everything else is buried to protect it from the environment. The main vault containing the batteries and electronics is buried about four feet deep, while the instruments are buried in shallower pits.

Preparing to cover the vault with plywood

The team prepares to cover the vault of one of the South Pole stations with plywood to protect it from drifting snow.

Every pit is covered with plywood to make it safer for the devices and easier to dig up again. Precipitation deposits snow for the team uncovering the devices. However, when Macon and Kim were digging up PG2 they found that they had to shovel 2.5 feet of snow to uncover the main vault.

“The equipment is specifically designed to be set while wearing gloves, except for the coax cable for the radio. You still have to take your gloves off to attach that,” Clauer says. “The best thing I found was the chemical hand warmers. Even in Antarctica, they last about seven hours,” he adds. “We were lucky that there wasn’t much wind,” he reports. “If there’s wind, then it’s even colder and you can’t keep the snow shoveled.”

The stations also are affected by the extreme dryness. “Because it’s so dry, our electric tower gets a lot of electrical potential produced by the blowing snow,” Clauer says. Static electricity is a big problem. “You’re on 3 km of ice, so grounding is nearly impossible. We ground our stuff to the tower, which is floating and changing potential all the time.”

The Trip

Of the four, Kim is the only one with previous experience at the South Pole. This was his fourth trip to Antarctica and third to the Pole, and he even recognizes some of the same people from previous trips. “I think there are two different types of people; one type really loves to be back, for others one time is fine,” he says, “but whenever I go, I see some of the same faces.” He finds something different every time, however. Not only was this his first time camping on the remote Antarctic Plateau, but it was also his longest trip so far. “Staying for so much longer was very physically challenging. There was much more work involved and even very simple tasks could be a challenge,” he says.

Clauer’s previous experience had been in Greenland, which he says was a “smaller, simpler operation. Antarctica is huge by comparison — there is a much bigger learning curve. Greenland is not quite as high, and not quite as cold.”

Travelers are advised to spend their first days at the South Pole acclimating to the altitude. Deshpande explains, “if you get serious altitude sickness, you may have to be evacuated. You already are short of breath, and it’s cold, so your body doesn’t really work normally at all. Just walking around is a pain. Climbing stairs to get up to the galley to eat is a big deal. And it’s such a cold air that it just cuts your throat. You have to fight your own body to get stuff done.”

“What struck me the most,” Macon declares, “was realizing how treacherous the continent is. As you get out to the South Pole, it hits you that this place is really cold. Antarctica really just doesn’t care if I make it out of here or not. It inspires a certain amount of respect.” But Macon admits that the experience was worth it. “This wasn’t a super-fun field trip,” he says, “It took a lot of effort and commitment to get through it, but I’m proud of our team.”

By the second day, the team was ready to start installing the two platforms. One of the locations was 3/4 of a mile from the station. “It would take at least an hour to walk there, and you’d arrive totally exhausted,” says Macon, so they traveled by snowmobile. It took about five days to get the first system set up, at which point the team split. Macon and Kim went camping out to PG2 while Clauer and Deshpande stayed to install the second platform.

Camping

The field camp established on the Antarctic Plateau to recover malfunctioning station PG2 (84.42°S, 57.96°E).

Although being inside the elevated station was comfortable, out in the field it was extremely cold. Macon, Kim, and a professional mountaineer went camping by PG2 to try to fix the system or, failing that, to pack it up and bring it home. “It’s quite an experience,” says Kim, who had never camped out during any of his previous trips. “The South Pole is already high, so everyone has some altitude sickness. Where we were camping was 2000 feet higher than the South Pole. We were okay, but we had to breathe harder.”

It took the first day to set up the camp. The second day they tried to troubleshoot the system, then packed it up. By the end of that day, the three were ready to be picked up. But that evening the wind picked up.

“When we first got out there, we could see forever, it’s just this ocean of white. But when the wind gets up strong enough to kick up the snow, it just starts closing in on you and turns into a gray soupy mess,” Macon reports.

“happy camper” students sit around a rectangular snow table

The team went through a “Happy Camper” course at McMurdo before deploying to the South Pole.

The trio had plenty of supplies, since campers in Antarctica are required to take enough food to last for seven days longer than they think they will need to be out. According to Macon, “it was just kind of a mental struggle. There’s nothing to do.”

Kim adds, “it’s not like you’re stuck at an airport. You’re in the middle of nowhere, only three people doing nothing with no civilization around.” Luckily, the plane was able to make the trip the following day.

Celebrations

The team celebrates New Year 2011 at the South Pole

The team celebrates New Year 2011 at the South Pole

Celebrating the winter holidays at the South Pole was a unique experience. “They had a really nice Christmas dinner for us,” says Deshpande. “They put the blinds down so that it looked like evening in spite of the 24-hour sunlight. Everyone was dressed up, and the food was good. There was even a Yule log on the flat-screen televisions!”

Because the ice sheet and South Pole station move, the location of the actual rotational pole shifts relative to the station over time. A surveyor is brought to the station each year and on New Years Day, a new pole is placed at the proper location of the south rotational pole. The team was part of the moving of the pole ceremony, a yearly New Year’s event.

Bob Clauer participates in moving the ceremonial south pole marker

Bob Clauer passes the 2011 South Pole marker in the annual pole moving ceremony.

This year, however, marks the 100th year since the South Pole was first visited, and there is a special centennial pole to mark the occasion. Every resident at the station forms a line from the old pole to the new location and passes the new pole hand-to-hand to the new location.