Keutsch Group Takes to the Air

This summer, Professor Frank Keutsch, third-year graduate students Jen Kaiser and Kate Skog, and former postdoctoral fellow Glenn Wolfe relocated to Europe to conduct field research. These members of the Keutsch group in the Department of Chemistry collaborated with the Pan-European Gas-Aerosol-Climate Interaction Study (PEGASOS). Thanks to their lightweight and unique fiber laser-induced-fluorescence (LIF) formaldehyde instrument, the Keutsch group was the only U.S.-based group invited to participate in the project’s Zeppelin component, the first of its kind. This instrument helps researchers “understand atmospheric processes that produce pollutants,” says Keutsch.

PEGASOS involves atmospheric chemists from more than 15 countries who are working to study and address the impact of air quality on climate change. This summer, PEGASOS launched the Zeppelin field campaign. The approximately 82-yard-long Zeppelin was equipped to house more than one ton of research instruments from collaborating institutions. During the campaign, the Zeppelin travelled through the Netherlands, Germany, Austria, Slovenia, and Italy; one scientist travelled onboard during each trip, and the trips averaged about six hours.

Because ozone formation is influenced by biogenic emissions of volatile organic compounds (VOCs) from plants and man-made emissions such as nitrogen oxides (NOX), the field campaign was intentionally conducted during the summer at the height of tree emissions and photochemical activity. The group chose the Po Valley location because it is one of the most polluted areas in Europe.

The Po Valley site where Kate Skog collected dataSkog collected data at one of the co-located PEGASOS ground sites using a different type of instrument developed in the Keutsch group. Some mornings, she could see the mountains in the valley area, while other mornings the pollution obscured the mountains, she says. Her site was located in a rural area, about an hour outside of Bologna, Italy. In addition to the Zeppelin flights, the PEGASOS project maintained a handful of ground sites throughout Europe that provided complementary data to those of the Zeppelin flights. A van equipped with similar instrumentation also followed the Zeppelin flight path on the ground during several flights to provide additional complementary data.

Collaborating researchers developed several instrumentation packages for the Zeppelin; Kaiser was onboard for many of the flights that involved the photochemistry package. During these flights, she supervised and maintained eight instruments, one of which was the Keutsch group’s LIF instrument.

Jen Kaiser onboard the ZeppelinDuring her two-month stay in Europe, a normal flight day for Kaiser involved looking at the chemical forecast to see predictions for the day’s atmospheric conditions and pollution, getting to the airport at 4 a.m., prepping the Zeppelin to take off an hour later, and adjusting the flight plan in response to the real-time data collected onboard.

Many of the flight paths traversed both cities and forests. “I can’t think of a better setting [in which] to do science,” says Kaiser. “As the sun comes up, you can watch the pollution form, both spatially and temporally.”

For Skog, the highlight of the experience was meeting scientists who are interested in similar areas of research. “You have to collaborate in this field,” she says.

The shared data set, which comprises data from all of the collaborators’ instruments, is one of the benefits to participating in a collaborative field. For now, the data captured during this field campaign will be shared among the collaborating research groups. In the future, however, the group plans to share the data set through a publicly accessible data archive.

Photochemistry instrumentation aboard the ZeppelinKeutsch and his students plan to remain involved in the Zeppelin portion of next year’s PEGASOS field campaign, which will take place in Finland — one of the least polluted areas in Europe. They are also planning to conduct a similar field campaign on an airplane in the U.S. Their novel LIF instrument is also drawing interest from researchers who are looking to conduct field campaigns spanning the Pacific from pole to pole and in the Amazon.

Read “Science at Sunrise,” a PEGASOS post written by Glenn Wolfe.
Learn more about the Keutsch group.

Story by Libby Dowdall