Atmospheric science fellow explores breakdown of compounds that impact lifetime of greenhouse gases

Jared Brewer, advised by Emily Fischer and A.R. Ravishankara, was awarded an ASCENT travel fellowship in March 2017. The fellowship supported his two-month stay this summer in Orleans, France, where he studied atmospheric chemistry at a unique research facility. The Department of Atmospheric Science Assisting Students, Cultivating Excellence, Nurturing Talent (ASCENT) program was founded in fall 2014 to help enrich the graduate experience. One component of ASCENT is an international travel grant that allows students to pursue opportunities for research outside the U.S.

With the support of the ASCENT award as well as an additional EUROCHAMP-2020 research grant, Brewer spent his time at the Institut de Combustion Aérothermique Réactivité et Environment (ICARE), a CNRS laboratory, investigating the quantum yields of the carbonyl species, Methyl Ethyl Ketone (MEK). Like acetone, MEK is important in atmospheric chemistry because it has a sufficiently long lifetime (5 days in the case of MEK) to be lofted into the upper troposphere. Outdoor chamber experiments using natural sunlight measured rates of MEK photolysis as well as bench-top experiments that measured UV absorption cross-sections of MEK at atmospherically relevant wavelengths and temperatures. The data will help improve the modeling of these compounds, and therefore understanding of the upper troposphere radical budget, upper troposphere ozone production, and lifetimes of pollutant and greenhouse gases.

In Orleans, Brewer worked with his advisor, Dr. Ravishankara, as well as the director of ICARE Dr. Abdelwahid Mellouki. The work enhanced his graduate research experience by giving him the opportunity to get practical research knowledge in a laboratory setting, rather than through computer modeling.

“As someone with no chemistry lab experience prior to this study, the opportunity to do cutting-edge research using a one-of-a-kind atmospheric chamber was hugely valuable to my progress as a researcher,” said Brewer. “The insights into experimental methods that I gained by first-hand laboratory experience will make me a better modeler and more complete atmospheric chemist going forward.”

University Distinguished Professor A.R. Ravishankara, who co-advises Brewer and worked with him at ICARE, said the ASCENT program benefits both the visiting student and host scientists.

“ASCENT is an amazing catalyst that enables our students to experience a very diverse and different learning environment and produce cutting-edge science. Not only did Jared learn from his experience by doing experimental work, he also gave a lot to the students and post-docs in Orleans by teaching them how to use the Master Chemical Mechanism codes (MCM),” he said.

Ravishankara added that there are other, intangible benefits to the program:

“The social aspect of this is immeasurable. I am sure that this two-month stay will be with Jared for life, and the people in Orleans got a lot from his presence there – an experience they will keep forever. It really builds international collaboration and cooperation.”