Congratulations to group members Kyle Custard and Kevin McAvey, who both successfully defended their dissertations today. Dr. McAvey now goes to Signature Science, LLC, and Dr. Custard o Schlumberger. Way to go fellas, and don’t forget to write!

Congratulations to former Shepson Group members Obie Cambaliza, Dana Caulton, Alyssa Hendricks, Kelly Mays, Brittany Moser, Chase Miller, Charles Obermeyer, and current group members Olivia Salmon and Tegan Lavoie, whose paper, entitled “Quantification and source apportionment of the methane emission flux from the city of Indianapolis,” was published yesterday in the journal Elementa.  Way to go everyone! You can read the paper here.

Abstract: We report the CH₄ emission flux from the city of Indianapolis, IN, the site of the Indianapolis Flux Experiment (INFLUX) project for developing, assessing, and improving top-down and bottom-up approaches for quantifying urban greenhouse gas emissions. Using an aircraft-based mass balance approach, we find that the average CH4 emission rate from five flight experiments in 2011 is 135 ± 58 (1σ) moles s^-1 (7800 ± 3300 kg hr^-1). The effective per capita CH₄ emission rate for Indianapolis is 77 kg CH₄ person^-1 yr^-1, a figure that is less than the national anthropogenic CH₄ emission (~91 kg CH4 person-1 yr-1) but considerably larger than the global figure (~48 kg CH₄ person^-1 yr^-1). We consistently observed elevated CH₄ concentrations at specific coordinates along our flight transects downwind of the city. Inflight investigations as well as back trajectories using measured wind directions showed that the elevated concentrations originated from the southwest side of the city where a landfill and a natural gas transmission regulating station (TRS) are located. Street level mobile measurements downwind of the landfill and the TRS supported the results of aircraft-based data, and were used to quantify the relative contributions from the two sources. We find that the CH₄ emission from the TRS was negligible relative to the landfill, which was responsible for 33 ± 10% of the citywide emission flux. A regression of propane versus methane from aircraft flask samples suggests that the remaining citywide CH₄ emissions (~67%) derive from the natural gas distribution system. We discuss the combination of surface mobile observations and aircraft city-wide flux measurements to determine the total flux and apportionment to important sources.

Congratulations to Dana, who successfully defended her thesis on Friday! Dana’s thesis is entitled “Aircraft-based measurements for the identification and Quantification of Sources and Sinks in The Carbon Cycle.” Dana will be headed to Princeton University in January to work with Mark Zondlo, investigating fugitive methane emissions in the Marcellus region. We wish Dana all the best. Don’t forget about us now that you’re in the big time!

Update January 4, 2015: Picture from graduation!

Former Shepson Group member Dennis Barket (Ph.D., 2001) was recently named one of the Purdue Department of Chemistry 2014 Outstanding Alumni. Way to go, Dennis!

Press release text:

Dr. Barket co-founded Griffin Analytical in November of 2001 with aspirations to bring lab-quality analysis to field applications. He has led the analytical instrumentation company from its inception through its merger into ICx Technologies and subsequent acquisition of ICx by FLIR Systems. Dennis now serves as Vice President of FLIR Detection.

Since 2001, Griffin has been awarded numerous contracts from the United States Department of Defense and other Federal agencies. In 2006, Griffin achieved national recognition by winning the TIBBETTS Award for excellence in Small Business and Innovation Research (SBIR). Griffin is currently focused on delivering monitoring and chemical detection equipment to the Department of Defense and Department of Homeland Security with an emphasis on fieldable mass spectrometry.

Dr. Barket obtained his Ph.D. in Analytical Chemistry from Purdue University. His graduate work was funded by a NASA Graduate Research Fellowship award in the area of applied mass spectrometry focused on analysis of biogenic precursors of ground level ozone. While concluding his Ph.D. work, Dennis also completed the Applied Management Principles Program through Purdue’s Krannert School of Management, which provides scientists and engineers with a “mini-MBA” experience.

Dr. Barket earned his undergraduate degree at Indiana University with a double major in Biology and Chemistry. Subsequent to his undergraduate work, he joined Procter and Gamble as a Research Associate where he worked as a member of an upstream product development team.

Dr. Maria “Obie” Cambaliza is leaving the Shepson Group after four years as a postdoctoral research associate to accept a professor position in the Department of Physics, Ateneo de Manila University. We are sad to see her go, but wish her only continued success and happiness! Thanks for all of the hard work, kind words, and smiles.

Goodbye Obie!

Professor Shepson was awarded the 2015 American Chemical Society Award for Creative Advances in Environmental Science & Technology “…for seminal advances in our understanding of the chemistry of remote and polluted atmospheres through an elegant combination of laboratory, field and modeling studies.”  The award is sponsored by the ACS Division of Environmental Chemistry. Way to go Shep, former, and current group members!!!

The Shepson Group’s very own Dr. Shepson will be joining the National Science Foundation as Director of the Division of Atmospheric and Geospace Sciences. Way to go Shep and the Shepson Group!  Read below the formal announcement from NSF:

“Dr. Shepson comes to the Foundation from Purdue University where he holds appointments as the Jonathan Amy Distinguished Professor in both the Department of Chemistry and the Department of Earth, Atmospheric, and Planetary Sciences. Paul earned his B.S. in Chemistry from SUNY Cortland and his Ph.D. from the Pennsylvania State University in atmospheric chemistry. He brings extensive research and management experience to the Foundation. Dr. Shepson has 170 publications to his credit on an array of topics in atmospheric chemistry in the Arctic and in forest environments as well as in analytical chemistry, and in aviation-based atmospheric research. Paul also played key roles in organizing several national and international collaborative studies in atmospheric sciences including PROPHET, OASIS, AICI and INFLUX. His contributions to the community include service as an Associate Editor for both JGR-Atmospheres and for Elementa, and service on NSF advisory panels.  Additional information can be found at https://www.stonybrook.edu/commcms/somas/people/_profiles/paul-shepson and https://www.science.purdue.edu/shepson/.

Dr. Shepson brings to the Division and Foundation his experience in several management positions, including Head of the Department of Chemistry and Founding Director of the Purdue Climate Change Research Center at Purdue University, and Director of the York University Centre for Atmospheric Chemistry in Toronto. The Department of Chemistry is comprised of around 50 faculty and 300 graduate students and is one of the largest in the nation.

Dr. Shepson’s appointment will be effective September 15, 2014.

Congratulations to Dana (first author), Dr. Shepson, Obie, whose paper “Methane Destruction Efficiency of Natural Gas Flares Associated with Shale Formation Wells” was published in Environmental Science and Technology today! Way to go! Click here to read it. Abstract below:

Flaring to dispose of natural gas has increased in the United States and is typically assumed to be 98% efficient, accounting for both incomplete combustion and venting during unintentional flame termination. However, no in-situ measurements of flare emissions have been reported. We used an aircraft platform to sample 10 flares in North Dakota and 1 flare in Pennsylvania, measuring CO₂, CH₄ and meteorological data. Destruction Removal Efficiency (DRE) was calculated by assuming a flare natural gas input composition of 60-100% CH₄. In all cases flares were greater than 99.80% efficient at the 25% quartile. Crosswinds up to 15 m/s were observed, but did not significantly adversely affect efficiency. During analysis unidentified peaks of CH₄, most likely from unknown venting practices, appeared much larger in magnitude than emissions from flaring practices. Our analysis suggests 98% efficiency for non-sputtering flares is a conservative estimate for incomplete combustion and that the unidentified venting is a greater contributor to CH₄ emissions.

Shown above is Jon Amy (seated, center), with Mike Everly (current Director, JAFCI), Bob Santini (Director Emeritus), and group members (left to right, Fulizi Xiong, Dr. Obie Cambaliza, Dana Caulton, Angela Raso, Tegan Lavoie, Wes Halfacre, Kyle Custard, and Kevin McAvey.

On July 18, 2014, the Purdue Board of Trustees ratified Dr. Shepson’s appointment as the Jonathan Amy Distinguished Professor of Chemistry, and Earth, Atmospheric, and Planetary Sciences. This recognition reflects the combined achievements of the Shepson Group, and collaborators from prior years, including when the group was at York University in Toronto.

Through this appointment, Dr. Shepson chose to honor and recognize the lifetime contributions to student education and achievement made by Dr. Jonathan Amy, a staff member at Purdue who created the Jonathan Amy Facility for Chemical Instrumentation (JAFCI). A large fraction of the work (aircraft instrumentation, development of instruments for field measurements (e.g. in the Arctic) and development of automated instruments for both lab and field work) conducted in the Shepson Group at Purdue has been supported and enabled by JAFCI. The Jonathan Amy Distinguished Professorship honors Jon, and recognizes both the many contributions of University staff and the importance of instrumentation to achievements in experimental science. More about Jon Amy is provided below, from a recent press release, on the occasion in May 2014 of the award to Jon of an Honorary Doctorate from Purdue. Thank you, Jon, and JAFCI!

“Jonathan W. Amy, of Lafayette, Indiana, whose doctoral degree work in the mid-1950s resulted in the formal creation of Purdue’s Chemistry Instrumentation Facility, with a mission of fusing science and technology through collaboration and creation.

The lab is named the Jonathan Amy Instrumentation Facility, and some 60 years later, the mission has expanded to include much of the university.

“Prof. Jonathan Amy conceived and implemented a unique vision for research in the chemical sciences involving a partnership between faculty, graduate students and a professional instrumentation staff that has made indelible contributions to research, industrial interactions and faculty careers at Purdue over the past 50 years. This model, implemented as the Jonathan W. Amy Facility for Chemical Instrumentation, has been widely admired nationally.

“To illustrate its impact, five Purdue chemists, including Jon Amy himself, have won the American Chemical Society’s award in Chemical Instrumentation. An unselfish person, Prof. Amy established the infrastructure that allowed the success of the others. Similarly, Jon Amy’s influence was deeply felt by each of seven Purdue people who have won the highest national award in analytical chemistry, the ACS Analytical Chemistry award. That seven Purdue people should have excelled at the level represented by these awards is in significant part due to the infrastructure that Jon Amy created.

“Dr. Amy used strong personal ties to the fledgling tech industry nationally to introduce not-yet-commercialized instrumentation with a huge competitive advantage to Purdue. He did this in gas chromatography, in mass spectrometry, in x-ray photoelectron spectroscopy, in high field NMR and in laser spectroscopy. Many outstanding chemists at Purdue joined the institution (or turned down competitive offers to stay here) because of Jon Amy.

“Prof. Scott McLuckey has a unique perspective on this having worked on instrumentation with direct help from Jon Amy as a graduate student, then having spent two decades in a well-equipped National Lab he returned to Purdue in 2000: ‘Jonathan Amy established a facility and, more importantly, a culture that enables Purdue researchers to realize dreams.’

“Once and current Chemistry Department Head Tim Zwier notes that ‘This legacy of strong partnership between the Amy facility and our starting assistant professors is one that remains today, accelerating the research productivity of our young faculty and setting our department apart from its peers.’

“Jonathan Amy’s record decidedly does not lie in his publications but in the many people whom he influenced very deeply. His career is a refreshing example of unselfish service of the highest quality to Purdue University.”

Source: University News Service and R. Graham Cooks

Congratulations to Wes (first author), Dr. Shepson, and former group members Kerri Pratt, Travis Knepp, and Chelsea Thompson, whose paper “Temporal and spatial characteristics of ozone depletion events from measurements in the Arctic” was published in Atmospheric Chemistry and Physics today!  Way to go! Click here to read it. Abstract below:

“Following polar sunrise in the Arctic springtime, tropospheric ozone episodically decreases rapidly to near-zero levels during ozone depletion events (ODEs). Many uncertainties remain in our understanding of ODE characteristics, including the temporal and spatial scales, as well as environmental drivers. Measurements of ozone, bromine monoxide (BrO), and meteorology were obtained during several deployments of autonomous, ice-tethered buoys (O-Buoys) from both coastal sites and over the Arctic Ocean; these data were used to characterize observed ODEs. Detected decreases in surface ozone levels during the onset of ODEs corresponded to a median estimated apparent ozone depletion timescale (based on both chemistry and the advection of O₃-depleted air) of 11 h. If assumed to be dominated by chemical mechanisms, these timescales would correspond to larger-than-observed BrO mole fractions based on known chemistry and assumed other radical levels. Using backward air mass trajectories and an assumption that transport mechanisms dominate observations, the spatial scales for ODEs (defined by time periods in which ozone levels ≤15 nmol mol⁻¹) were estimated to be 877 km (median), while areas estimated to represent major ozone depletions (<10 nmol mol⁻¹) had dimensions of 282 km (median). These observations point to a heterogeneous boundary layer with localized regions of active, ozone-destroying halogen chemistry, interspersed among larger regions of previously depleted air that retain reduced ozone levels through hindered atmospheric mixing. Based on the estimated size distribution, Monte Carlo simulations showed it was statistically possible that all ODEs observed could have originated upwind, followed by transport to the measurement site. Local wind speed averages were low during most ODEs (median of ~3.6 m s⁻¹), and there was no apparent dependence on local temperature.”