UCI heading to South Pole to gauge human impact on atmosphere

The Orange County Register

June 16th, 2008

By Gary Robbins

Our Leigh Boerner reports:

A UC Irvine scientist will fly to the “bottom-of-the-world” in December to collect infinitesimal clues about how everything from exhaust belched by cars in Orange County to the deforestation of the Amazon basin has affected the world’s atmosphere over the past century.

Atmospheric chemist Murat Aydin is going to help reconstruct climate history by capturing samples of air from the loose ice just below the glacier surface at South Pole Station, an outpost that scientists say is one of the most inhospitable spots on Earth. Temperatures routinely fall to minus 22 degrees … in the polar summer.

The air contains thousands of chemicals at very low levels, some of which have an impact on climate change. Analyzing the level of those chemicals tells how the world’s atmosphere has evolved over time and provide clues to what we might expect in the future.

“We are trying to learn about the history of our atmosphere. It is impossible to predict the future or even understand the present without knowledge about the past,” says Aydin, a research scientist in UCI’s Department of Earth System Science.

Aydin’s team will be accessing the past by drilling holes into the loose ice layer, where air can settle in the spaces between the ice crystals. Here very small amounts of these chemical can accumulate because air can still flow freely into the loose ice, where it then stays. Aydin will remove this air by pumping it out with tubes and packing it into special flasks. He can look at the amount and what types of chemical are there, and compare it to what the air looks like today.

“It helps us to understand how things are changing,” Aydin says. For example, burning of the Amazon rain forest changes the chemical makeup of the air around the equator. But since this air mixes with the air in the rest of the world, the chemicals released in these fires are dispersed into the global atmosphere in about one year. Some of these chemicals make it to the South Pole, where can they settle down into the snow layer. More snow falls on top, turns to ice, then effectively acts as a storage beaker, containing the trace chemicals for future analysis.

The chemicals that Aydin wants to look at are present in concentrations of only parts per trillion. That’s one molecule floating around with 1,000,000,000,000 other molecules. Back at the lab in Irvine, Aydin will count the minuscule amount of relevant molecules and separate them into types. From this information, he and other scientists will be able to see the impact of our changing use of the world on the atmosphere, and predict what effects these changes might have. In some cases, the individual chemicals can even be traced back to their origins. This way, scientists can link the pollutants back to specific events in the past. This information could help scientists see what types of events cause changes in our atmosphere, and lead them to understand what we should do the future to prevent global climate change.

Aydin’s work is funded by a new grant from the National Science Foundation, which awarded $225,000 to the UCI-based research team.