Jesse Kroll

2013 James B. Macelwane Medal Winner

Jesse H. Kroll was awarded the 2013 James B. Macelwane Medal at the AGU Fall Meeting Honors Ceremony, held on 11 December 2013 in San Francisco, Calif. The medal is for “significant contributions to the geophysical sciences by an outstanding early career scientist.”


Jesse Kroll is playing a leading role in unraveling the extremely complex multiphase atmospheric chemistry of organic molecules emitted by both anthropogenic activities and biogenic processes. His work is particularly important because atmospheric organic species form a large fraction of airborne submicron particulate matter (PM), which is responsible for most of the adverse human health effects, including premature mortality, attributed to poor air quality. Submicron aerosol PM also drives important direct and indirect impacts on atmospheric radiative transfer, causing much of the uncertainty in our understanding of current, and predictions of future, climate change.

Jesse started his mastery of atmospheric organic chemistry as a very productive student in Jim Anderson’s lab at Harvard, focusing on gas phase reaction mechanisms and kinetics of volatile organic compounds with atmospheric oxidants. After a short postdoctoral stint at Harvard he moved on to John Seinfeld’s California Institute of Technology (Caltech) laboratory, where he played a major role in developing and utilizing advanced environmental chambers and a wide range of analytical instrumentation to determine mechanisms and yields of secondary organic aerosol (SOA) particle formation, simulating a range of atmospheric conditions for the photooxidation and condensation of a wide variety of organic vapor precursors.

After three years at Caltech, Jesse returned to the Boston area, joining Aerodyne Research, Inc. (ARI), where he played a leading role in groundbreaking collaborative laboratory measurements using a range of specialized environmental chambers and flow reactors combined with advanced aerosol mass spectrometers and other instruments that better defined the oxidation kinetics and SOA yields for a wide variety of individual organic compounds as well as complex emission sources. This work involved collaborative experiments with colleagues at Harvard University, Boston College, Colorado State University, Lawrence Berkeley National Laboratory, Carnegie Mellon University, and the University of Helsinki.

Since moving on to the Massachusetts Institute of Technology (MIT) in 2009, Jesse has continued many of the collaborations initiated at ARI and established important new ones. He has continued designing and performing a wide range of laboratory and field experiments, many focused on understanding and quantifying the heterogeneous mechanisms and kinetics of SOA particle oxidative aging. He is also engaged in important instrument development work, including the design and field use of a novel method to quantify gas phase emissions of low-volatility organic molecules that are powerful SOA precursors but avoid detection by current gas phase organics monitoring methods. He has also worked with MIT engineers and ARI scientists to develop and utilize advanced aerosol mass spectrometric techniques to better quantify the soot and primary organic aerosol emissions from automotive and aircraft engines.

Just 10 years past his Ph.D., Jesse has an amazing publication record, including 66 archival papers with a collective citation count over 4000, a dozen cited 100 times or more. Several of these papers are fast becoming classics; I anticipate that many of Jesse’s future papers will as well. His Macelwane Medal recognizes extraordinary early career achievements that I expect will be eclipsed by Jesse’s future discoveries.

—CHARLES KOLB, Aerodyne Research, Inc., Billerica, Mass.


Thanks, Chuck, for the kind words and for the nomination, and thanks to AGU for this great honor. I consider myself extremely lucky to have received this award and luckier still to have worked (and to continue to work) with so many impressive and generous people throughout the atmospheric chemistry community. I owe them all a great deal of thanks.

First are my various advisors and mentors—all were hugely important in my scientific training and, happily, all continue to be important in my career today. My Ph.D. advisor, Jim Anderson, provided an ideal environment for learning how to think about and carry out research in atmospheric chemistry. It was also Jim who suggested that I give aerosol chemistry a try; I thought he was nuts at the time, but (as usual) he was right. My experience as a postdoc, focused on secondary organic aerosol, was extremely exciting and rewarding; I owe that to my postdoctoral advisor, John Seinfeld, who (despite being busier than probably anyone I know) is infinitely generous with his time, support, and ideas. My time at Aerodyne was equally special, thanks to Doug Worsnop as well as John Jayne and Chuck Kolb, terrific bosses who run one of the most intellectually dynamic research communities I know of. And probably most important is Neil Donahue, someone who was never my advisor in a formal sense but who has been my primary mentor throughout my entire scientific career. The advice and support he’s given me, starting back in my undergraduate days, are the main reasons I’m in science today.

I also feel fortunate to have worked with, and learned from, so many wonderful lab mates, coworkers, and colleagues over the years. I can’t possibly mention everyone here, but people whom I specifically want to acknowledge include Jim Clarke, Sally Ng, Manjula Canagaratna, and Tim Onasch. More recently, my collaboration with Kevin Wilson has resulted in the most fun, challenging, and productive research I’ve been involved in. And having Colette Heald as a colleague is a real pleasure—without her collaboration and her friendship, I’d like my job far less than I do now. (I’d certainly be much worse at it.) I also want to thank all the members of my group—Sean Kessler, Anthony Carrasquillo, Kelly Daumit, James Hunter, Eben Cross, Ellie Browne, Kelsey Boulanger, Jon Franklin, and Chris Lim—who made starting up and running a lab about as easy and enjoyable as it could possibly be.

Most generally, I’m grateful to the atmospheric chemistry community as a whole for providing such a friendly, open, and collaborative environment and for being so supportive of junior scientists. It’s a special community, and I feel very lucky to be a part of it.

Finally, my biggest thanks go to my wife, Amy. I used up all my husband points long ago, but Amy remains a continual source of strong support, great advice, and endless fun, and I owe her a lot.

—JESSE H. KROLL, Massachusetts Institute of Technology, Cambridge, Mass.