It's a long way from downtown Toronto to Ellesmere Island in the Canadian High Arctic. It's much farther still to the planet Mars. But Kimberly Strong's scientific curiosity about the makeup of planetary atmospheres has led her to study all these places.
"Studying Toronto's urban air quality and comparing that to atmospheric pollution in the Arctic helps us understand the global nature of air pollution—where it originates, where it goes, and what it does to the planet," says Dr. Strong. "The chemical makeup of the atmosphere is a rich source of information about the overall state of a planet—whether that’s our own planet or others."
The NSERC-funded Professor of Physics from the University of Toronto uses spectroscopy—the study of the interaction between matter and radiated energy—to better understand the composition of the atmosphere. Since each gas has a unique spectroscopic “fingerprint”, it is possible to accurately measure concentrations of substances in the atmosphere, such as ozone, greenhouse gases and pollutants like carbon monoxide, that can serve as key vital signs for the health of the global environment.
Dr. Strong’s research has led to a better understanding of the health of the ozone layer—a protective shield in the atmosphere that absorbs the solar ultraviolet rays that are harmful to life on Earth. In particular, she has gained new insight into how this shield repairs itself. "While the signs are encouraging when it comes to ozone, one of the things we are finding is that ozone recovery can be volatile—it can vary greatly from one year to the next," says Dr. Strong.
Now, her work is also contributing to a better understanding of other planets. Dr. Strong is working with the Canadian Space Agency (CSA) to probe the atmosphere of Mars and search for sources of methane, whether biological or geological. "This exciting research will measure the chemical composition of the Martian atmosphere with unprecedented sensitivity and spatial coverage, providing insights into the origins of trace gases on the planet and potentially helping to solve the mystery of methane on Mars," says Dr. Strong.
So far, scientists have only been able to speculate on the source of large quantities of methane found in the Red Planet’s atmosphere. Adding to the mystery is the fact that methane levels deplete much faster than they should. Discovering the source of the gas—and the cause of its depletion—could reveal geological culprits, like methane-spewing volcanoes, or possibly microbial life forms, like bacteria that feed on methane.
The instrument Dr. Strong is working with—the Mars Atmospheric Trace Molecule Occultation Spectrometer will travel to Mars aboard the European Space Agency’s ExoMars Trace Gas Orbiter in 2016. That missions findings may reveal a great deal about Mars’ ability to sustain life and pave the way for future missions.