A5062047319- Atmospheric chemistry and aerosols
- Air Quality Monitoring and Forecasting
- Air Quality and Health Impacts
- Vehicle emissions and performance
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Odor and Emission Control Technologies
- Hydrocarbon exploration and reservoir analysis
- Advanced Chemical Sensor Technologies
- Water Quality Monitoring and Analysis
- Advanced Fiber Laser Technologies
- Atmospheric aerosols and clouds
- Risk and Safety Analysis
- Nuclear Physics and Applications
- Radiation Therapy and Dosimetry
- Radiation Detection and Scintillator Technologies
- Industrial Gas Emission Control
- Analytical Chemistry and Sensors
- Particle physics theoretical and experimental studies
- Conservation Techniques and Studies
- Insect Pheromone Research and Control
- Aerosol Filtration and Electrostatic Precipitation
- Particle Detector Development and Performance
- Toxic Organic Pollutants Impact
Colorado Department of Public Health and Environment
2013-2023
Institute of Nuclear Physics of Lyon
1996-2016
University of Colorado Boulder
2010-2014
Cooperative Institute for Research in Environmental Sciences
2010-2014
NOAA Earth System Research Laboratory
2010-2014
National Oceanic and Atmospheric Administration
2011
Abstract. We report the physical and chemical effects of photochemically aging dilute biomass-burning smoke. A "potential aerosol mass" (PAM) flow reactor was used with analysis by a high-resolution mass spectrometer proton-transfer-reaction ion-trap during FLAME-3 campaign. Hydroxyl (OH) radical concentrations in reached up to ~1000 times average tropospheric levels, producing effective OH exposures equivalent 5 days atmosphere, allowing for us extend investigation smoke beyond oxidation...
The magnitude and sources of chlorine atoms in marine air remain highly uncertain but have potentially important consequences for quality polluted coastal regions. We made continuous measurements ambient ClNO(2) Cl(2) concentrations from May 15 to June 8 aboard the Research Vessel Atlantis during CalNex 2010 field study. In Los Angeles region, was more ubiquitous than most nights study period. ranged detection limits at midday campaign maximum values night reaching 2100 200 pptv,...
Abstract. Nitryl chloride (ClNO2) is produced at night by reactions of dinitrogen pentoxide (N2O5) on containing surfaces. ClNO2 photolyzed during the morning hours after sunrise to liberate highly reactive chlorine atoms (Cl·). This chemistry takes place primarily in polluted environments where concentrations N2O5 precursors (nitrogen oxide radicals and ozone) are high, though it likely occurs remote regions lower intensities. Recent field measurements have illustrated potential importance...
Abstract. Volatile organic compound (VOC) mixing ratios were measured with two different instruments at the T1 ground site in Mexico City during Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign March of 2006. A gas chromatograph flame ionization detector (GC-FID) quantified 18 light alkanes, alkenes acetylene while a proton-transfer-reaction ion-trap mass spectrometer (PIT-MS) 12 VOC species including oxygenated VOCs (OVOCs) aromatics. GC separation system was...
[1] Recent laboratory and field studies have indicated that glyoxal is a potentially large contributor to secondary organic aerosol mass. We present in situ measurements acquired with recently developed, high sensitivity spectroscopic instrument during the CalNex 2010 campaign Pasadena, California. use three methods quantify production loss of Los Angeles its contribution aerosol. First, we calculate difference between steady state sources sinks at Pasadena site, assuming remainder available...
The sea breeze/land breeze diurnal circulation within the Los Angeles Basin and adjacent waters transports marine air into basin during day urban to Santa Monica Bay night. Nitryl chloride, ClNO 2 is a nocturnal trace gas formed from heterogeneous reaction of dinitrogen pentaoxide (N O 5 ) with chloride containing aerosol. Its photolysis after sunrise produces atomic chlorine radicals regenerates NO , both which may increase ozone production. Mixing source salt x in provides conditions ideal...
Abstract This proof‐of‐concept study demonstrates that methane (CH 4 ) emissions from natural gas (NG) and agriculture can be disentangled using the concept of excess column observations. A network cost‐effective sensors measured column‐averaged dry‐air mole fractions for CH (ΔXCH ), ethane (ΔXC 2 H 6 as NG tracer), ammonia (ΔXNH 3 agriculture) in Denver‐Julesburg Basin during March 2015. ΔXCH varied up to 17 ppb was >3 times higher with winds directions where is produced. The variance...
Abstract Global atmospheric concentrations of methane (CH 4 ), a powerful greenhouse gas, are increasing, but because there many natural and anthropogenic sources CH , it is difficult to assess which may be increasing in magnitude. Here we present data set δ 2 H‐CH measurements individual air the Colorado Front Range, USA. We show that not 13 C, signatures consistent sampled downwind landfills, cattle feedlots, oil gas wells region. Applying these source ground aircraft samples indicates at...
Abstract The Research at the Nexus of Air Quality and Climate Change (CalNex) field campaign was undertaken to obtain a better understanding regional impacts different pollution sources in California. As part this study, real‐time shipboard measurements were made size‐resolved, single‐particle mixing state submicron supermicron particles (0.2–3.0 µm aerodynamic diameter) along California coast where major differences noted between Southern Northern In California, containing soot up largest...
The study objective was to use a preliminary risk based framework evaluate the sufficiency of existing air data answer an important public health question in Colorado: Do volatile organic compounds (VOCs) emitted into from oil and gas (OG) operations result exposures Coloradoans living at or greater than current state setback distances (500 feet) OG levels that may be harmful their health? We identified 56 VOCs Colorado compiled 47 monitoring datasets measured these 34 locations across...
Abstract We describe the resources used, deployment strategy, and outcomes of Front Range Air Pollution Photochemistry Éxperiment (FRAPPÉ) experiment, which took place in summer 2014 Colorado. provide a history air quality region previously conducted experiments, atmospheric conditions encountered during campaign, summarize scientific findings that campaign produced, together with Deriving Information on Surface Conditions from Column Vertically Resolved Observations Relevant to Quality...
Several regions within California have significant air quality issues. Transport of pollutants emitted in one region to another may add the impact local emissions. In this work, Lagrangian particle dispersion model simulations show amounts tracers that are transported and among four regions, Southern California, San Francisco Bay Area, Central Valley, rest state. The cover May June 2010, Research at Nexus Air Quality Climate Change experiment period. Tracers automobile emissions type...
We present results from a field study monitoring methane and volatile organic compound emissions near an unconventional oil well development in Northern Colorado September 2019 to May 2020 using mid-infrared dual-comb spectrometer. This instrument allowed quantification of methane, ethane, propane single measurement with high time resolution integrated path sampling. Using ethane as tracer gases for gas activity, we observed during the drilling, hydraulic fracturing, millout, flowback phases...
Abstract. We report the physical and chemical effects of photochemically aging dilute biomass-burning smoke. A potential aerosol mass "PAM" flow reactor was used with analysis by a high-resolution spectrometer proton-transfer reaction ion-trap during FLAME-3 campaign. Hydroxyl (OH) radical concentrations in reached up to ~ 1000 times average tropospheric levels, producing effective OH exposures equivalent 5 days atmosphere. VOC observations show aromatics terpenes decrease aging, while...
Abstract. During the Texas Air Quality Study II (TexAQS 2006) campaign, a PEroxy Radical Chemical Amplifier (PERCA) was deployed on NOAA research vessel R/V Brown to measure total peroxy radicals (HO2+Σ RO2). Day-time mixing ratios of HO2+Σ RO2 between 25 and 110 ppt were observed throughout study area – Houston/Galveston region Gulf coast US analyzed in relation measurements nitrogen oxides, volatile organic compounds (VOC) photolysis rates assess radical sources sinks region. The used...
Abstract. Volatile organic compound (VOC) mixing ratios were measured with two different instruments at the T1 ground site in Mexico City during Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign March of 2006. A gas chromatograph flame ionization detector (GC-FID) quantified 18 light alkanes, alkenes acetylene while a proton-transfer-reaction ion-trap mass spectrometer (PIT-MS) 12 VOC species including oxygenated VOCs (OVOCs) aromatics. GC separation system was...
Abstract. Nitryl chloride (ClNO2) is produced at night by reactions of dinitrogen pentoxide (N2O5) on containing surfaces. ClNO2 photolyzed during the morning hours after sunrise to liberate highly reactive chlorine atoms (Cl·). This chemistry takes place primarily in polluted environments where concentrations N2O5 precursors (nitrogen oxide radicals and ozone) are high, though it likely occurs remote regions lower intensities. Recent field measurements have illustrated potential importance...
Abstract. During the Texas Air Quality Study II (TexAQS 2006) campaign, a PEroxy Radical Chemical Amplifier (PERCA) was deployed on NOAA research vessel R/V Brown to measure total peroxy radicals (HO2+ΣRO2). Day-time mixing ratios of HO2+ΣRO2 between 25 and 110 ppt were observed throughout study area – Houston/Galveston region Gulf coast U.S. analyzed in relation measurements nitrogen oxides, volatile organic compounds (VOC) photolysis rates assess radical sources sinks region. The used...
We deploy a mid-infrared dual-comb spectrometer in van for field measurements of volatile organic compounds (VOCs). also use similar, laboratory system to measure ambient VOCs over 2km round-trip path. Work the US Government and not subject copyright.