The Explorers - At the poles
Britney Schmidt, an assistant professor in the School of Earth and Atmospheric Sciences, has made three polar plunges to Antarctica. At McMurdo Station, her team, including engineers from the Georgia Tech Research Institute led by Mick West, built a robotic underwater vehicle called Icefin and deployed it to explore the underside of the ice shelves flowing off the continent.
The team has been trying to figure out how these ice shelves interact with the ocean, a process that’s poorly understood. These are the first explorations of their kind.
“I love physics and love that you can apply it to the natural world, but I don’t want to just do physics on a whiteboard,” Schmidt said. “I came to Georgia Tech because it was possible to do these missions.”
The clues they find about the environment under Antarctica’s ice shelves, and the life that thrives in these harsh conditions, will help in the search for life on other planets, namely Europa, a moon of Jupiter. Antarctica’s icy oceans are remarkably similar to Europa’s ice-capped oceans.
Photos: McMurdo Station
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“Every day that I walk outside on Antarctica, I feel like I’m standing on Europa. It’s another world,” Schmidt said. “It’s like I tell my group: You’re standing on a place that people died to get to less than 100 years ago. Even though we’re here now with boats and a buffet, you can’t lose track of that.”
Schmidt isn’t the only Georgia Tech scientist working in Antarctica. Jeannette Yen, a professor of biology, completed her third polar plunge in December 2014. Her team is studying an organism that serves as a “canary in the coal mine” for climate.
From aboard the research vessel Lawrence M. Gould, they cruise past giant icebergs and through rafts of loose ice to Palmer Deep, a location where the water is 2,000-feet (600 meters) deep. From the ship, they lower plankton nets into the zero-degree Celsius water and haul live animals aboard. They carry each day’s catch back to the lab at Palmer Station. There, the scientists study plankton swimming motion with video cameras in a room kept at zero degrees Celsius, to mimic the animals’ natural environment.
Plankton are the base of the food chain, but their environment is changing. Around the southern continent, the water temperature is stable at around zero degrees Celsius because of the Antarctic Circumpolar Current. Carbon dioxide, a potent greenhouse gas, easily dissolves in the cold water, acidifying the ocean. The acidifying oceans might be triggering a destructive chain of events underwater that could harm the food web around the world.
On the voyage home from Palmer Station, a humpback whale surfaced behind their boat for a few minutes. The whale was close enough for Yen to see the barnacles around the mouth and on the fins. The whale cleared its blowhole and dove under the boat, its tail never breaking the surface.
“These huge creatures are dependent on tiny aquatic organisms at the bottom of the food chain for survival,” Yen said. “Knowing that is what keeps me coming back to Antarctica.”
At the other pole, Greg Huey, professor and chair in the School of Earth and Atmospheric Sciences, is exploring the atmosphere above the Arctic. Huey conducts flight missions above the Arctic Circle to collect samples of the atmosphere.
“You see just an endless expanse of white when you look out,” Huey said.
Members of his lab don protective face gear as they venture into the frigid landscape to work on their atmospheric monitors on the ground. His lab found unprecedented levels of molecular chlorine in the air above Barrow, Alaska. The study was the first time molecular chlorine had been measured in the Arctic, and the first time that scientists had documented such high levels of molecular chlorine in the atmosphere — levels that have a strong influence on the Arctic’s atmospheric chemistry. The chlorine could affect the concentrations of mercury and ozone in the northern atmosphere.
“We go there to measure very reactive species in the air because you can’t bring them home to do it,” Huey said.