Joost de Gouw

Measurements and Modeling of GUV222-Driven Increases in SOA Concentrations in an Unoccupied Office The COVID-19 pandemic led to heightened interest in germicidal ultraviolet (GUV) lamps, which can deactivate bacteria and viruses in infectious aerosols. Recently, lamps using 222 nm (GUV222) light to...

A new paper from Madison Rutherford studies SOA formation from the use of germicidal UV in an office. She also found that many VOCs increased in the office when the GUV lamps were on, apparently from surface reactions of ozone or direct irradiation by the lamps. doi.org/10.1021/acsestair.5c00475

Madison Rutherford showing off her latest progress with our Vocus-IMS to a captive audience.

Also, Brigitta Rongstad wrote a news release at cires.colorado.edu/news/house-fires-release-harmful-compounds-air.

Laboratory Analysis of VOC Emissions from Structural Materials in Wildland–Urban Interface Fires The wildland–urban interface (WUI) has grown in recent decades at the same time as wildfires have expanded in range and scope. Fires at the WUI are therefore more common, and structural materials make up more of the wildfire fuel mass. While emissions from biomass fires are fairly well understood, volatile organic compound (VOC) emissions from structural fires are less constrained. In this study, we perform measurements of VOC emissions from small-scale laboratory burns of 18 different structural materials across 78 experiments using a Vocus proton-transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS) to better understand these unique emissions. We calculate emission factors for 73 VOCs across all materials, including aromatics and polycyclic aromatic hydrocarbons (PAHs). We compare the emissions from both flaming and pyrolysis, which separate the processes of direct release of VOCs from combustion formation. Mass spectra comparisons were used to qualitatively highlight high-emission compounds across materials and identify notable emissions (e.g., nylon monomers) and potential tracers (e.g., halogen species) for WUI fires. Using these data, the emissions from a whole-house fire were compared with those from an equivalent mass of wood, and we found that some aromatic and nitrile species may be suitable WUI fire tracers.

The paper is at doi.org/10.1021/acs.est.5c11276

I am very proud of this paper from Will Dresser in our group: he participated in a laboratory study led by Shantanu Jathar to investigate the emissions from the burning of building materials. What we found is that emissions of some toxics like benzene are far higher from the burning of plastics.

Being nice to CU is a big thing in Korea. Many of their convenience stores advertise it. @colorado.edu

I am not at the AMS meeting this week, but William Dresser from our group is in Houston and will present on Wednesday his work on volatile organic compounds from fires at the wildland-urban interface. ams.confex.com/ams/106ANNUA...

Beautiful day for a new group photo!

Two new graduate students are joining our group. Heejoo Kang comes from the Gwangju Institute of Science and Technology and is interested in formaldehyde. Audrey Lyp holds a BS from the University of Wisconsin-Madison and wants to work on wildfire impacts on the atmosphere. Welcome both!

Great to see so much support from our community for NCAR.

Finally, we had 2 sabbatical visitors this year. Prof. Hwajin Kim from Seoul National University was with us until the Summer and then Prof. Siegfried Schobesberger from Eastern Finland University joined our group.

Soon after we celebrated with a game night.

In November, it was Will Dresser’s turn to defend his PhD thesis, and he was also successful in fending off all the questions.

In September, Lindsey Anderson received the Sheryl R. Young Award for her work on wildfires. This award is open to graduate students from across the Boulder campus. cires.colorado.edu/spotlights/c...

In August, Alex received the 2024 Best Paper Award from the Analytical Chemistry division in our department for his work on air pollution disparities in Denver. Alex attended the meeting remotely from his new job in France.

Also in July, Madison Rutherford received a Graduate Scholarship award from the Rocky Mountain States Section of the Air & Waste Management Association.

In July, Joost assumed the Chair position in the Department of Chemistry.

Later in May, Matt Shulman deployed our Vocus Elf during the indoor air quality study CLEAN at a home in Boulder.

A few days later, we gathered for a much happier event as we celebrated the graduations of Alex Bradley and Emmy Longnecker!

The lowlight of our year happened in May, when Madison Rutherford was in California taking VOC samples on a landfill, and the project was abruptly cancelled by the EPA.

Deep transfer learning method for seasonal TROPOMI XCH4 albedo correction Abstract. The retrieval of methane from satellite measurements is sensitive to the reflectance of the surface, and in many regions, especially those with agriculture, surface reflectance depends on th...

Later in April, Alex' paper came out on methane in Colorado observed from the TROPOMI and GOSAT satellite instruments. doi.org/10.5194/amt-18-1675-2025

In April, Alex Bradley and Emmy Longnecker successfully defended their PhD theses on the exact same day!

Volatile Organic Compounds Inside Homes Impacted by Smoke from the Marshall Fire Wildfires at the wildland–urban interface (WUI) have been increasing in frequency over recent decades due to increased human development and shifting climatic patterns. The work presented here focuses...

Also in January, Will Dresser published his first paper on the Marshall Fire. He showed that VOCs in a smoke-impacted home remained elevated for weeks. doi.org/10.1021/acsestair.4c00259

Emissions and Chemistry of Volatile Organic Compounds in the Los Angeles Basin in Summer 2022 Concentrations of aromatic hydrocarbons in Los Angeles have declined since 2010 while those of oxygenated volatile organic compounds (VOCs) are similar or higher Midday photochemistry was ∼68% fa...

In January, former student Andrew Jensen published a paper on VOC measurements in Los Angeles in Summer 2022. He showed that emissions had declined since an earlier study, but OH chemistry had sped up. doi.org/10.1029/2024JD041812

As 2025 is drawing to a close, it is time to commemorate the group's highlights and one lowlight. Our group had a great year despite all the upheaval in the science world. Let’s get started.

Finally, Lindsey will present an analysis of air quality data from Denver with a focus on the comparison between different metrics for photochemical aging. She is in the last year of her PhD and interested in postdoctoral opportunities. agu.confex.com/agu/agu25/me...

Also on Friday, Nathan will present his work with NIST on measurements of methane and ammonia from cattle using frequency comb spectroscopy. agu.confex.com/agu/agu25/me...

On Friday, Drew will present his work on the measurements and analysis of VOCs at the ASCENT site in Denver. agu.confex.com/agu/agu25/me...

On Monday, Lindsey will discuss her work to develop a new Chemistry curriculum for the Partnerships for Informal Science Education in the Community (PISEC) program. agu.confex.com/agu/agu25/me...

Unfortunately, I will not be at the AGU Fall Meeting this year. There is too much work left as Department Chair, plus I am prioritizing the travel of my students. Our group will be represented by Lindsey Anderson, Drew Blauth and Nathan Sweet.