Dylan B. Millet

Congratulations to Kelley Wells on winning a Research Technical Staff Award for "distinguished service to the University of Minnesota research community"! It's richly deserved.

science.orgSurface temperatures drive strong seasonality in urban reactive carbon emissionsUrban air quality is affected by diverse volatile organic compounds (VOCs), and prior studies reveal a need to understand their seasonal sources. We combine high-resolution mass spectrometry with eddy...

New paper out in Science Advances by lead author @mvermeuel.bsky.social 🧪 Surface temps drive strong seasonality in urban reactive carbon emissions doi.org/10.1126/scia... A joint project between the @dbm.bsky.social and @chemdelphine.bsky.social groups, in collab w/ @roseatmos.bsky.social group

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@mvermeuel.bsky.social shows that air quality models do not adequately represent this temperature dependence, and this needs to be a priority so that we can make better predictions

with Tim Griffis, @emfranklin.bsky.social, Trey Maddaleno, Katelyn Richard, Rose Rossel, Jeff Peischl

@mvermeuel.bsky.social shows in this paper that in summertime NY, VOC emissions come predominantly from volatile chemical products (e.g. paints, solvents, cleaners, etc), vegetation, and even residences (wood decomposition products!) - rather than from traffic.

Many of those non-traffic sources are very temperature sensitive, and were much lower in winter - when traffic was the main VOC source. This temperature sensitivity is important because it means that their emissions will increase during heat waves and as climate warms.

The measurements were made from a cell tower to get high enough above the surrounding infrastructure, and were collected during both summer and winter

VOCs have important impacts on air quality, and their emissions from emissions from vehicles have declined by >70% in the last 20 years ... so other urban VOC sources can now be more important.

During the Fluxes of Reactive Organic Gases in NY (FROG-NY) project we used eddy covariance to measure the fluxes of a wide range of volatile organic compounds (VOCs) over an urban footprint on Long Island, NY.

18 Aug

Group outing! With traditional cribbage tourney 🧪

amt.copernicus.orgAirborne eddy covariance measurements of ocean-air VOC fluxes: Distinguishing signal from noiseAbstract. Ocean-atmosphere exchange plays an important but uncertain role for many volatile organic compounds (VOCs). Airborne eddy covariance (EC) enables direct flux quantification over large areas,...

New paper out in Atmos. Meas. Tech. by lead author Xin Chen 🧪 Airborne eddy covariance measurements of ocean-air VOC fluxes: Distinguishing signal from noise amt.copernicus.org/articles/19/...

TL/DR: instrument noise is a big limitation! A relatively modest noise reduction compared to current capabilities would go a long way in improving the utility of eddy covariance for this application

With major contributions from Glenn Wolfe, Erin Delaria, Julian Deventer, Markus Müller, Arne Schiller, Lee Thornhill, and Armin Wisthaler

New paper out in Atmos. Meas. Tech. by lead author Xin Chen 🧪 Airborne eddy covariance measurements of ocean-air VOC fluxes: Distinguishing signal from noise amt.copernicus.org/articles/19/...

Ocean-air exchange is a major source (and sink!) for many important atmospheric organic compounds, but these fluxes are poorly understood. In this paper, Xin explores the capabilities and limitations of the eddy covariance technique for directly measuring these exchange rates.

Eddy covariance has seen broad application over land, but not for air-sea exchange of organics where fluxes are usually weak and challenge instrument detection limits. Xin's work shows how instrument noise and turbulence interact to determine what we can/cannot measure in this way.

@atmchemaerojobs.bsky.social

8 Aug

Scenes from the Telluride Workshops 2026. If you know these people you may be an atmospheric chemist 🧪

Dylan B. Millet reposted

AtmChemAerosolJobs

13 July

Postdoc in Atmospheric Science and Machine Learning at SRON, Leiden, on Carbon Monoxide emissions from cities and steel plants using TROPOMI satellite observations: werkenbijsron.nl/en/vacancies...

werkenbijsron.nlPost-Doc in Atmospheric Science and Machine Learning

z.umn.eduMobileLabPostdocAd-ConcisePostdoctoral Researcher The Kenagy Lab (Department of Chemistry; https://kenagy.chem.umn.edu/) and the Millet Lab (Department of Soil, Water, and Climate; https://atmoschem.umn.edu) at the University ...

9 July

Bump! Priority deadline July 15 🧪

Hannah S Kenagy@hannahskenagy.bsky.social

The Kenagy and Millet Labs at UMN are hiring a postdoc to deploy mass spectral instruments on a new mobile lab focused on air composition, air quality, and environmental justice. Details at z.umn.edu/bdjg. Contact Hannah (hskenagy@umn.edu) & Dylan @dbm.bsky.social (dbm@umn.edu) with questions!

Dylan B. Millet reposted

Hannah S Kenagy

@hannahskenagy.bsky.social

New paper out in Earth’s Future by lead author @xueyingyu.bsky.social 🧪 Multi-species constraints resolve methane source versus sink changes: lessons from 2020 doi.org/10.1029/2025...

doi.orgMulti‐Species Constraints Resolve Methane Source Versus Sink Changes: Lessons From 2020Combining satellite measurements of the methane-HCHO-CO oxidation chain with methyl chloroform data disentangles methane sources and sinks Year-2020 methane sources and sinks reveal simultaneous ...

CH4, HCHO, and CO are thus linked by OH, and concurrent satellite obs of all 3 offer complementary info for parsing methane sources vs sinks. Here Xueying leverages that idea to investigate causes for the year-2020 methane acceleration.

5 June

Her results confirm the idea that slower CH4 removal (due to reduced NOx) and a larger wetland source combined to drive the 2020 surge. I think her paper also highlights the critical value of comprehensive, multi-species satellite obs (UV/Vis/IR) for tracking our atmosphere and how its changing

5 June

New paper out in Earth’s Future by lead author @xueyingyu.bsky.social 🧪 Multi-species constraints resolve methane source versus sink changes: lessons from 2020 doi.org/10.1029/2025...

5 June

A challenge for understanding the atmospheric methane (CH4) budget lies in telling if concentration changes are due to its sources or sink (OH). The main sink? Reaction with OH, producing formaldehyde (HCHO). HCHO then reacts (partly with OH) to produce CO, which reacts with OH to produce CO2.

science.orgU.S. researchers face new restrictions on publishing with foreign collaboratorsNIH, NASA grantees are confused and concerned amid agencies’ piecemeal communication

29 May

Tell me you don't understand how scientific research works without saying you don't understand how scientific research works 🧪 www.science.org/content/arti...

28 Apr

Touring the NASA P-3 research aircraft ... used for atmospheric chemistry and other important research on our home planet 🤓 🧪

z.umn.eduPostdocAd-GXSPostdoctoral Associate: Geostationary measurements of atmospheric chemistry Join us! Our atmospheric chemistry group at the University of Minnesota (UMN) is seeking applications for a Postdoctoral A...

8 Apr

Priority application deadline is April 20! 🧪 #ChemSky

Dylan B. Millet@dbm.bsky.social

Postdoc opening: Geostationary measurements of atmospheric chemistry Join us! Our group seeks a postdoc to work on space-based measurements of atmospheric chemistry with the new generation of geo-IR satellite instruments. See z.umn.edu/b5iz for details & contact me (dbm@umn.edu) with questions!

If you are in Zürich and interested in this topic consider joining us at the Collegium Helveticum on Tuesday (5pm) collegium.ethz.ch/events/fello...

collegium.ethz.ch📅 Tracking Atmospheric Change from Space | Collegium HelveticumEarth’s atmosphere is undergoing rapid and far-reaching change, with consequences that extend from local air quality to the global climate system. The …

dx.doi.orgFirst Aircraft‐Based VOC Measurements Using Thermal Infrared Remote Sensing: Mapping Fire Plumes With the Scanning High‐Resolution Interferometer Sounder (S‐HIS)Wildfires release a wide range of gases that are poorly quantified but strongly influence air quality and human health We show that aircraft-based infrared remote sensing can be used to map key w...

17 Feb

New group paper from Chengyuan Hu! First Aircraft-Based VOC Measurements Using Thermal Infrared Remote Sensing dx.doi.org/10.1029/2025...

Results reveal clear wildfire VOC enhancements and track the ensuing plume evolution. The study provides a foundation for future aircraft-based remote sensing. It also shows that instrument noise is a critical factor for future IR sounders to enable trace gas measurements

New group paper from Chengyuan Hu! First Aircraft-Based VOC Measurements Using Thermal Infrared Remote Sensing dx.doi.org/10.1029/2025...

17 Feb

Fires are a global source of atmospheric volatile organic compounds (VOCs). Airborne remote sensing offers a new way to map these emissions and understand impacts. Chengyuan developed the first VOC retrieval for an aircraft-based IR sounder and used it to map fire VOC emissions in the western US!

11 Feb

Two new faculty openings at U. Minnesota 🧪 Assist. Prof. in Climate Science hr.myu.umn.edu/jobs/ext/372... Questions: Tim Griffis, tgriffis@umn.edu Assist. Prof. in Soil Physics / Ecohydrology / Hydropedology hr.myu.umn.edu/jobs/ext/372... Questions: David Mulla, mulla003@umn.edu Due March 13

8 Dec 2025

Group photo! With special guests Mr. & Mrs. C, Chewy, and Brent

Dylan B. Millet reposted

juli g pausas

@jgpausas.bsky.social

2 Dec 2025

The new Global Fire Emissions Database (GFED5, 2002–2022) shows that at the global scale 1) by far, most area burned are grasslands; 2) area burned is declining; & 3) fuel consumption is increasing: ie, fires are increasing in forests & encroached grasslands. www.nature.com/articles/s41... 🧪🌍🔥🌳🌐

drive.google.comUMN IonE - Interdisciplinary Sustainability Research Professors.png

25 Nov 2025

Job openings: sustainability research profs at the UMN Institute on the Environment: drive.google.com/file/d/1L5gp...

20 Nov 2025

My main question for this mass-based scholarly index is whether it can include the SI sections www.nature.com/articles/d41...

meetingorganizer.copernicus.orgSession AS3.2

20 Nov 2025

👀

Colette Heald@coletteheald.bsky.social

If you work on sources and impacts of VOCs (biogenic or anthropogenic) from measurement to modeling perspectives please submit an abstract to our atmospheric organics session at #EGU26! Our invited speakers are @dbm.bsky.social and @jacquirickard.bsky.social See you in Vienna! tinyurl.com/55vda8u7

z.umn.eduPostdocAd-FarmFluxPostdoctoral Associate: aircraft-based measurements of atmospheric ammonia Join our team! The atmospheric chemistry group at the University of Minnesota (UMN) seeks applications for a Postdoctoral A...

20 Nov 2025

Postdoc opening: airborne NH3 measurements Join our team! The UMN atmospheric chemistry group is recruiting a postdoc to collect and analyze airborne NH3 measurements as part of NASA FarmFlux. See z.umn.edu/aw67 for details, & contact Julieta (junco004@umn.edu) and I (dbm@umn.edu) with questions!

Dylan B. Millet reposted

Emily Barnes Franklin, PhD

@emfranklin.bsky.social

1 Oct 2025

Out this week in npj Climate and Atmospheric Science: VCPs, biogenic VOCs and traditional anthropogenic PM respond to heat and smoke to drive summer PM pollution outside NYC, highlighting vulnerabilities of urban air quality under global change. @chemdelphine.bsky.social @dbm.bsky.social

rdcu.beEmerging drivers of urban aerosol increase global change vulnerability in a US megacitynpj Climate and Atmospheric Science - Emerging drivers of urban aerosol increase global change vulnerability in a US megacity

@opinionhaver.bsky.social

8 Sept 2025

For sale, one sonic anemometer, lightly used

Dylan B. Millet reposted

William B. Fuckley

23 July 2025

Some memes are relatable they aren’t even like funny, just actively insulting.

Dylan B. Millet reposted

Jose D Fuentes

@jdfuentes.bsky.social

10 July 2025

Save data provided by NASA's Earth Science Division, as outlined by a letter in Science magazine www.science.org/doi/10.1126/... @biometlab.bsky.social @paulstoy.bsky.social @dbm.bsky.social @agu.org @ametsoc.org

science.orgNASA Earth Science Division provides key dataIn May, the US administration proposed budget cuts to NASA, including a more than 50% decrease in funding for the agency’s Earth Science Division (ESD) (1), the mission of which is to gather knowledge...

@stevenslbrown.bsky.social

10 July 2025

A letter in Science about the importance of NASA Earth Science from several members of the recently-dissolved NASA Earth Science Advisory Committee. Out today online and in the 7/24 issue. www.science.org/doi/10.1126/...

Dylan B. Millet reposted

Steve Brown

11 Apr 2025

Clouds darkening over NOAA research. We are slated for elimination in next years budget. Astonishing loss to the nation and the world if it happens.

Paul Voosen@voosen.me

BREAKING from @science.org: The Trump admin is seeking to kill nearly all climate research at NOAA, its climate science agency. Its near-final budget proposal would end all NOAA research labs, academic institutes, and regional climate centers. And it wants to fully end the NOAA Research division.

science.orgTrump seeks to end climate research at premier U.S. climate agencyWhite House aims to end NOAA’s research office; NASA also targeted

27 Mar 2025

Sometimes you *should* meet your (science) heroes. Stan was a giant of chemical kinetics and just a gem of a person. We will miss him.

Paul Wennberg@paulowennberg.bsky.social

@NASA and @caltech.edu kineticist extraordinaire Stan Sander died Saturday night surrounded by his family. Stan was a kind mentor, inventive scientist and engineer. He will be sorely missed by me and many colleagues around the world.