Researchers Return to Antarctica in Pursuit of Elusive Scientific Mystery
Posted November 17, 2003 | Atlanta
A mystery in the skies above Antarctica and in the ice below its snow pack is the subject of a new scientific expedition being led this month by a team of investigators from the Georgia Institute of Technology.
It is to be the first of two expeditions to the South Pole region that will provide data for the four-year, $1.8 million Antarctic Tropospheric Chemistry Investigation (ANTCI), a grant funded by the National Science Foundation's Office of Polar Programs.
Ten other institutions are involved in the project, including major involvement by scientists at the National Center for Atmospheric Research in Colorado plus contributions from researchers at the University of California, Irvine and NASA's Langley Research Center in Virginia, among others. The National Center for Atmospheric Research is managed by the University Corporation for Atmospheric Research under primary sponsorship by the National Science Foundation.
This first ANTCI expedition runs Nov. 15 through Jan. 4, 2004. A second expedition is planned for 2005 or 2006. The 2003 expedition includes the participation of Jill Beach, a teacher from Rockdale County High School in Conyers, Ga., who will communicate what she does at the South Pole with her students via an interactive Web site.
"Antarctica is a land of mystery. But with these expeditions, we're going to be probing some fundamental questions posed by science about the region," said Professor Emeritus Doug Davis, ANTCI's mission scientist and the project's co-principal investigator along with Principal Research Scientist Fred Eisele, both from Georgia Tech's School of Earth and Atmospheric Sciences.
"In fact, we're rewriting the book on atmospheric chemistry in Antarctica," Davis said. "The data we're collecting down there is changing our whole view of what's happening in the atmosphere, and why."
The broad goal of ANTCI is to gain a better understanding of the air above Antarctica. This includes measuring two major chemical families in the atmosphere and in the local environment - sulfur and nitrogen -- and the oxidizing agents that affect their levels. Scientists also plan to measure the levels of several other trace gases that affect atmospheric chemistry.
Sulfur is of interest because it is a major component of the atmosphere above Antarctica, and it can be transferred from the air to the snow, where it eventually ends up in the ice. When it appears in ice-core samples going back thousands of years, it can be used to indicate major geophysical events from the past, such as volcanic eruptions, El Ninos and major climate changes.
But what has been puzzling about this data is that it shows much higher levels of sulfur in the atmosphere over the polar plateau than scientists have been able to explain, Davis said.
Similarly, both recent and earlier studies of the air, snow pack, and ice cores show large fluctuations in levels of reactive nitrogen at the South Pole. Atmospheric nitric oxide - normally considered a pollutant in most regions of the world - appears to have a natural source at the South Pole and its levels are higher by nearly a factor of 10 than they are at all other polar sites.
This finding continues to be one of the most baffling made by the earlier studies conducted by Georgia Tech researchers, Davis said, and the unexpected findings are what led scientists to propose the ANTCI project.
Back to the South Pole for Answers
There are several reasons why they need to better understand the processes at work affecting these levels of sulfur and nitrogen in the atmosphere, Davis said.
Chief among them is that a better understanding of these two families of gases affects how scientists interpret ice-core samples, which in turn affects global understanding of past atmospheres and, hence, climate and what might affect it today.
"Analysis of ice cores from the Antarctic glaciers are among the most important pieces of information we have for understanding past climates," said Professor Judy Curry, chair of the School of Earth and Atmospheric Chemistry. "Georgia Tech's major role in ANTCI reflects the strengths and unique capabilities of our atmospheric chemistry program."
Using specially outfitted aircraft this year and in 2005, ANTCI scientists will take air samples from a variety of locations above the polar region to gain a bigger and more detailed picture of what's happening to sulfur and nitrogen levels. Investigators also will make measurements at the South Pole's Atmospheric Research Observatory as well as take a variety of samples from the Antarctic snow pack.
"The chemistry of the atmosphere is what interests us," said Associate Professor Dave Tan, another member of the scientific expedition going to Antarctica this fall. "Ultimately, atmospheric chemistry relates to climate, which affects us all. Previously, we thought that the Antarctic atmosphere was inert, but it turns out, it's not."
In fact, the region's atmosphere is quite active. In 1998, NASA satellite data showed that the Antarctic ozone hole was the largest on record, covering 27 million square kilometers -- bigger than Antarctica's entire 14 million square kilometers of surface area.
Researchers in 1997 also found that increased ultraviolet light coming through the hole damages the DNA of ice fish, an Antarctic fish lacking hemoglobin, according to the CIA's World Factbook. It also reports that ozone depletion has been shown to harm one-celled Antarctic marine plants. And in 2002, significant areas of ice shelves disintegrated in response to regional warming.
This warming climate appears to be melting glaciers across the planet, Davis said, raising concern that the planet's sea levels may begin to rise in the coming decades, inundating coastlines from Florida to Indonesia. Scientists - not to mention policy makers and the general public - need to understand what might be happening in the atmosphere as a whole so as to understand that phenomenon, he said.
"The question is no longer whether there is a global climate change," Davis said. "The only question is why is it happening?"
Because ANTCI is a regional experiment, the data collected during this project also will be added to and compared with samples taken from other parts of the planet by various teams of researchers - including those at Georgia Tech - to gain a better idea of what the global atmosphere is like today, Tan said.
"We need to understand this," he said. "We've got to know what we're doing to the atmosphere, how quickly we're doing it and how critical is it?"
Sparking Interest in Science Among Students
An outreach component of the ANTCI project also involves the participation of Jill Beach, a teacher from Rockdale County High School in Conyers, Ga., who will communicate what she does at the South Pole with her students via e-mail and a daily journal posted on a Web site.
"Everybody at the school is really excited about my trip, and so am I," Beach said.
Rockdale is the site of a magnet program founded in 2000 that is devoted to intensive science study, and Georgia Tech faculty work actively with the school in a variety of projects. Beach teaches 59 students how to conduct research - from generating a research idea, to conducting experiments and reporting their results.
"The hope is that with this trip to Antarctica, we will be able to generate some interest among the students in what I'll be studying, which is atmospheric research that looks at sulfur and nitrogen compounds in the air," Beach said.
Beach will arrive in Antarctica around Nov. 19 and stay until about Dec. 5. Once there, she will assist ANTCI researchers in setting up experiments and compiling the data they collect.
During two ANTCI expeditions to the South Pole, researchers will use balloons and aircraft specially outfitted with spectrometers and other equipment that will test and sample the air in a variety of locations. This fall, they will use a deHavilland Twin Otter turboprop airplane to take two, four-hour missions a day between Nov. 21 and Dec. 7.
Instruments and sampling techniques designed by Georgia Tech researchers to measure levels of nitrogen and sulfur in the atmosphere will be aboard. Beach will be there to help.
"We've been studying this organic sulfur chemistry for some time at Georgia Tech, and we've developed new instruments that help us to understand the sulfur breakdown that's occurring in Antarctica and the many other chemical species that are facilitating this," Davis said.
"We don't know that what we see at the surface at South Pole extends out over the entire plateau - how far does it extend upwards and outwards? A kilometer? Ten kilometers? A hundred kilometers? How general is this phenomenon?" Davis said. "Once you see something that is totally unique, you want to know how big is it? How extensive is it? We don't know whether this phenomenon covers the plateau region of Antarctica. And we don't know how deep it is. How high is it? How important is it to the regional atmosphere, and what effect does it have on the rest of the atmosphere?"
"We need many new measurements," Davis said. "We have to have a very reliable measurements of many different species to understand the atmospheric chemistry there."
When the plane lands each day, downloading and compiling this important data will be one of Beach's tasks.
"Jill is going to be a part of that data processing after the flights, and she also will assist with preparing instruments for each trip," Davis said.
"The goal in a lot of these field exercises is to involve high-school teachers, to share some of the excitement that this land of mystery has to offer," he said. "We're trying to get that excitement into the high schools themselves, and what better way is there to do that than by getting teachers involved in the actual science?"
If teachers can become excited about current scientific questions, then they're going to take that excitement back with them to young people and, hopefully, spark an interest in science that will produce future investigators with more questions.
"Jill's experience there is likely to spawn some projects that she can share and involve students with here," Davis said. "Once she's in Antarctica, then she'll be exposed to a broad cross section of other people working in the sciences. I'm sure she'll walk away with ideas of projects she can do with her students."