Welcome to the Pratt Lab blog! Dr. Kerri Pratt is an assistant professor in the Departments of Chemistry and Earth & Environmental Sciences and faculty associate of the Program in the Environment at the University of Michigan. We study the chemical interactions of atmospheric trace gases, particles, clouds, and snow, with a focus on the Polar Regions and wintertime environments. Our interdisciplinary research has relevance to climate change, air quality, and human health. As an analytical chemistry lab, we primarily apply novel mass spectrometry techniques to our field research. We invite you to follow our adventures in (and outside!) the lab!

Friday, October 20, 2017

Sampling Smoke from a Controlled Burn at UMBS!

On Tuesday October 10th there was a controlled burn at the University of Michigan Biological Station. These burns are done every 20 years or so, allowing researchers to study how the forest responds to and recovers from fires. We were interested in sampling the smoke plume under these controlled conditions to gain a greater understanding that can be applied to wildfires that are currently ranging across the western US. Pratt Lab graduate students Nate and I (Nick) collaborated with Conner Daube and Ed Fortner from Aerodyne Research to conduct measurements the smoke plume during the burn. We used our new aircraft-aerosol time-of-flight mass spectrometer (A-ATOFMS) to sample over 25 thousand aerosol particles! In addition we also used a DRUM impactor to collect particle samples for off-line analysis by electron microscopy. This was an excellent opportunity to learn about the impacts of fresh biomass burning aerosols on air quality in a minimal risk situation. This field study was conducted in the incredible Aerodyne Mobile Laboratory! 
 Aerodyne Mobile Lab as we prepared for the burn.

 An inside view of the Lab. In the very back of the picture you can see Maverick (A-ATOFMS).

As a result of wet weather conditions, this burn was incomplete (evidenced by the green ferns in the burn area). It did however create plenty of smoke for us to sample.

 Sampling performed on Riggsville Road near the Biological Station.

Aftermath of the controlled burn - As you can see the moisture prevented a complete burn, but we still had plenty of aerosol particles!




Saturday, September 30, 2017

Welcome Nick and Christian!

Welcome Nick Ellsworth and Christian Keiser! Nick is a first-year rotation graduate student who recently received a B.S. degree at Utah Valley University, and Christian is a first-year undergraduate student participating in the Undergraduate Research Opportunity Program. Welcome to the Pratt Lab!

Friday, September 15, 2017

Arctic oil field aerosols paper published!

Congratulations to former Pratt Lab members Dr. Matt Gunsch (recent Ph.D.) and Dr. Katie Kolesar (post-doc) and current Pratt Lab Ph.D. student Rachel Kirpes for their paper describing the chemical composition of atmospheric particles transported to Utqiaġvik (Barrow), AK from the Arctic Ocean and Prudhoe Bay oil fields! "Contributions of transported Prudhoe Bay oil field emissions to the aerosol population in Utqiaġvik, Alaska" was recently published in Atmospheric Chemistry and Physics. Please check out the paper!

Thursday, September 7, 2017

Arctic Molecular Iodine Paper Published in PNAS!

Prof. Kerri Pratt and PhD student Angela Raso (co-advised by Prof. Paul Shepson at Purdue Univ.) completed the first measurements of Arctic tropospheric I2, produced from the sunlit coastal snowpack. Read about "Active molecular iodine photochemistry in the Arctic" in the Proceedings of the National Academy of Sciences of the U.S.A.!

Press Release Links:
Michigan News: Chemists discover molecular iodine in Arctic atmosphere, released by snowpack
Purdue News: First measurements of iodine in the Arctic reveal questions about air pollution

Tuesday, August 29, 2017

Thursday, August 24, 2017

Eclipse 2017!

On August 21st, the Pratt and Ault labs took an afternoon break to see the near-total solar eclipse over Ann Arbor! Fortunately, the unpredictable Michigan weather cooperated enough to see the 80% coverage before storm clouds rolled in. We all had a great time joining the hundreds of people who gathered on the UM Diag to view this amazing event!
The Pratt and Ault Labs on the UM Diag

Near 80% coverage, taken from a cell phone camera and behind solar eclipse glasses!
The tree canopy on the Diag acting as a camera obscura, projecting the crescent of the sun! Hundreds of spectators in the background
The cloud cover was just right to snap an unfiltered photo of the sun