Sea Ice and Climate in Antarctica
Part of the Antarctica: The Farthest Place Close to Home Curriculum Collection.
Martin Jeffries is a glaciologist employed by the Geophysical Institute of Alaska. Martin studies both poles, investigating how sea ice forms and interacts with polar air and oceans.
AMNH: Why should kids know about deep sea Antarctica?
Martin: Antarctica's the last great unspoiled wilderness, and a huge natural laboratory. I like to try to get students to Antarctica, where they can learn about actual research."
Field of Study Glaciology, investigating how sea ice interacts with climate
AMNH: What's so important about your field of study in Antarctica?
Martin: Sea ice plays a key role in the exchange of energy and mass between the ocean and atmosphere, and vice versa. Consequently, sea ice has a huge effect on climate, both locally and globally, and it also effects climate change and is affected by climate change. It's vital that knowing what's happening to the ice can help to understand regional and global climate variability and change.
AMNH: How do you study Sea Ice?
Martin: We usually have a hundred or so small injuries per season. This year, 191 people wintered over at McMurdo, so it's a relatively safe program. Several decades ago there were some deaths. People were caught in white-out conditions, which happens when blizzard conditions make it almost impossible to see. Others fell in crevasses, which are deep cracks in the ice sheet. There are crevasses all over the place; snow builds up over the cracks and you can't see them. A team goes out each season to search out safe routes and flag them. There's a Search and Rescue team of ten to fifteen people always in the station, and a bigger team in the summer, with vehicles that have radar and other tracking equipment.
AMNH: Describe a typical day of work in Antarctica.
Martin: Most of my field work has been conducted from the research vessel Nathaniel B. Palmer. I consult with the captain and the other scientists about our route and about our plans for field work. We work in the laboratories and freezer aboard the ship to analyze our snow and ice samples. We obtain those samples and other data by going out onto ice floes, often spending three to five hours working in the dark and cold. I spend a lot of time on the ship's bridge simply watching the ice to learn about its variability and appreciate its beauty. We all must spend some time on the bridge when the ship is moving, even in the middle of the night, because we maintain a program of standardized observations to record the changing nature of the ice cover. Sometimes the captain or officer of the watch will let you steer the ship, or you can watch the penguins on the ice, whales in the water, or the moon rising above an iceberg. In the evening I invariably spend a couple of hours in the science freezer cutting up ice cores. Believe it or not, this is fun! I have often said that when I cease to gain any satisfaction from cutting up the ice cores and seeing the many different textures and colours of the ice crystals, I will stop and find something new and exciting to do. I haven't reached that point yet. After working in the freezer, I always write up my daily science notes in my journal; and I always ask myself if we observed or measured anything new. If there is time, I will sit with a good book and a candy bar before setting the alarm if it's my turn to get up in the middle of the night to make ice observations. If I get a full night's sleep, I'm lucky.
AMNH: Is it dangerous?
Martin: In short, no. As long as one is aware of the potential hazards and is properly prepared, then the dangers can be mitigated and the likelihood of any casualties reduced. Because we are very safety-conscious we have never had any problems, even when ice floes have fractured beneath our feet.
AMNH: How do the ice cores help you in your research?
Martin: I examine ice cores collected from ice floes to study the growth processes of sea ice. I cut the ice cores in thin slices called thin sections; then I look at the size and shape of the ice crystals between crossed polarizing filters and sometimes under a microscope. We melt many ice samples for stable isotope analysis. The ice core analysis tells us about the processes that created that ice and the conditions under which it grew.
AMNH: Do you use remote sensing in your work?
Martin: I use satellite data on board ship to help with navigation. We also use satellite data to observe and analyze the condition of the ice. When I'm not in the field, I mainly use three kinds of satellite images. One, called synthetic aperture radar (SAR), shows sea ice in great detail regardless of darkness and cloud cover. Passive microwave instruments also "see" the ice surface through the clouds and dark, but over much larger areas than SAR. NOAA-AVHRR also covers broad areas, but is affected by the weather and light conditions. Nevertheless, by using combinations of these data it is possible to learn a lot about the ice cover.
AMNH: Is the work day back at home very different?
Martin: A typical day in the office involves routine tasks. I answer the phone, check e-mail, analyze data, work with colleagues and students, and take care of administrative tasks. I also prepare seminars, review research papers or proposals, and work on my own papers and proposals. Writing grant proposals is no fun, but seeing my research results get published is very exciting.
AMNH: How did you end up studying sea ice?
Martin: Sometimes I'm surprised I ended up a scientist! I never liked physics and math in school, but now that I'm a glaciologist, I use physics and math all the time! I sometimes think of myself as an accidental geophysicist. As a kid I always enjoyed geography, and I still remember Mr. Levy, the geography teacher who made it so interesting and relevant. Then I studied geography at the University of Sheffield in England, where I took a class called "Glaciers and Landscape" from Professor Waters. I ended up falling in love with glaciology. After graduating with a Bachelor of Arts degree, I worked on a project studying ice caps on the Arctic Circle in Norway for my MSC; and I got even more interested in studying glaciers–preferably overseas. I headed for graduate school and a Ph.D. at the University of Calgary, Canada. I was expecting to study glaciers in the Rocky Mountains; but good luck led me to Ellesmere Island, in northernmost Canada on the edge of the Arctic Ocean, to study ancient, multiyear sea ice. This ice may be 3,000 years old. I have worked at the Geophysical Institute of the University of Alaska Fairbanks since 1985, studying sea ice and lake ice in the Arctic and Antarctic.