A5012751433- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Wind Energy Research and Development
- Fluid Dynamics and Turbulent Flows
- Wind and Air Flow Studies
- Computational Fluid Dynamics and Aerodynamics
- Fire effects on ecosystems
- Air Quality Monitoring and Forecasting
- Ion-surface interactions and analysis
- Vehicle emissions and performance
- Air Traffic Management and Optimization
- Fluid Dynamics and Vibration Analysis
- Atmospheric aerosols and clouds
- Mass Spectrometry Techniques and Applications
- Engineering Education and Curriculum Development
- Meteorological Phenomena and Simulations
- Aerodynamics and Acoustics in Jet Flows
- Advanced Chemical Sensor Technologies
- Aviation Industry Analysis and Trends
- Turbomachinery Performance and Optimization
- Precipitation Measurement and Analysis
- Human-Automation Interaction and Safety
- Spectroscopy and Laser Applications
University of Colorado Boulder
1994-2025
Cooperative Institute for Research in Environmental Sciences
2021-2025
National Oceanic and Atmospheric Administration
2019-2025
NOAA Chemical Sciences Laboratory
2021-2025
University of Colorado System
1986-2025
Pennsylvania State University
2024
Saint Vincent College
2024
University of Hartford
2024
National Renewable Energy Laboratory
2002-2023
Skidaway Institute of Oceanography
2015-2023
Abstract Quantification of the black carbon (BC) and brown (BrC) components source emissions is critical to understanding impact combustion aerosols have on atmospheric light absorption. Multiple‐wavelength absorption was measured from fuels including wood, agricultural biomass, coals, plant matter, petroleum distillates in controlled settings. Filter‐based measurements were corrected compared photoacoustic results. BC segregated total extinction estimate BrC individual sources. Results...
Despite decades of declining air pollution, urban U.S. areas are still affected by summertime ozone and wintertime particulate matter exceedance events. Volatile organic compounds (VOCs) known precursors secondary aerosol (SOA) photochemically produced ozone. Urban VOC emission sources, including on-road transportation emissions, have decreased significantly over the past few through successful regulatory measures. These drastic reductions in emissions led to a change distribution...
Wildfires are a substantial but poorly quantified source of tropospheric ozone (O3). Here, to investigate the highly variable O3 chemistry in wildfire plumes, we exploit situ chemical characterization western wildfires during FIREX-AQ flight campaign and show that production can be predicted as function experimentally constrained OH exposure, volatile organic compound (VOC) reactivity, fate peroxy radicals. The exhibits rapid transition regimes. Within few daylight hours, formation...
Abstract. Wind energy is foundational for achieving 100 % renewable electricity production, and significant innovation required as the grid expands accommodates hybrid plant systems, energy-intensive products such fuels, a transitioning transportation sector. The sizable investments wind power development integration make financial operational risks of change very high in all applications but especially offshore. Dependence on level modeling simulation accuracy to mitigate risk ensure...
Abstract. Extensive airborne measurements of non-methane organic gases (NMOGs), methane, nitrogen oxides, reduced species, and aerosol emissions from US wild prescribed fires were conducted during the 2019 NOAA/NASA Fire Influence on Regional to Global Environments Air Quality campaign (FIREX-AQ). Here, we report atmospheric enhancement ratios (ERs) inferred emission factors (EFs) for compounds measured board NASA DC-8 research aircraft nine wildfires one fire, which encompass a range...
Abstract Accurately representing flow across the mesoscale to microscale is a persistent roadblock for completing realistic simulations. The science challenges that must be addressed coupling at these scales include following: 1) What necessary capture variability of flow, and how do we avoid generating spurious rolls within terra incognita between scales? 2) Which methods effectively couple correct nonstationary features microscale? 3) are best initialize turbulence 4) way handle...
Abstract We introduce the open-source ExaWind modeling and simulation environment for wind energy. The primary physics codes of are Nalu-Wind OpenFAST. is a wind-focused computational fluid dynamics (CFD) code that coupled to whole-turbine was created under U.S. Department Energy funding achieve highest-fidelity simulations turbines farms date, with goal enabling disruptive changes turbine plant design operation. Innovation will be gleaned through better understanding complex flow in farms,...
Abstract. Wildfires are increasing in size across the western US, leading to increases human smoke exposure and associated negative health impacts. The impact of biomass burning (BB) smoke, including wildfires, on regional air quality depends emissions, transport, chemistry, oxidation emitted BB volatile organic compounds (BBVOCs) by hydroxyl radical (OH), nitrate (NO3), ozone (O3). During daytime, when light penetrates plumes, BBVOCs oxidized mainly O3 OH. In contrast, at night or optically...
Understanding the efficiency and variability of photochemical ozone (O3) production from western wildfire plumes is important to accurately estimate their influence on North American air quality. A set measurements were made NOAA Twin Otter research aircraft as a part Fire Influence Regional Global Environments Air Quality (FIREX-AQ) experiment. We use zero-dimensional (0-D) box model investigate chemistry driving O3 in modeled plumes. Modeled afternoon reached maximum mixing ratio 140 ± 50...
Abstract Biomass burning is a major source of light‐absorbing organic aerosol (brown carbon), but its composition, chemical evolution, and lifetime are not well known. We measured water‐soluble brown carbon absorption from 310 to 500 nm on the National Oceanic Atmospheric Administration Twin Otter aircraft during flights downwind western United States wildfires in summer 2019. The sampling strategy was near‐Lagrangian plume ages spanned 0–5 hr. Trends mass coefficient with age varied between...
Abstract. We present a comparison of fast-response instruments installed onboard the NASA DC-8 aircraft that measured nitrogen oxides (NO and NO2), nitrous acid (HONO), total reactive odd (measured both as (NOy) from sum individually species (ΣNOy)), carbon monoxide (CO) in troposphere during 2019 Fire Influence on Regional to Global Environments Air Quality (FIREX-AQ) campaign. By targeting smoke summertime wildfires, prescribed fires, agricultural burns across continental United States,...
Increasing trends in biomass burning emissions significantly impact air quality North America. Enhanced mixing ratios of ozone (O3) urban areas during smoke-impacted periods occur through transport O3 produced within the smoke or pyrogenic volatile organic compounds (PVOCs) with nitrogen oxides (NOx = NO + NO2) to enhance local production. Here, we analyze a set detailed chemical measurements, including carbon monoxide (CO), NOx, and speciated (VOCs), evaluate effects transported from...
The declining trend in vehicle emissions has underscored the growing significance of Volatile Organic Compound (VOC) from Chemical Products (VCP). However, accurately representing VOC chemistry simplified chemical mechanisms remains challenging due to its complexity including speciation and reactivity. Previous studies have predominantly focused on VOCs fossil fuel sources, leading an underrepresentation VCP sources. We developed integrated mechanism, RACM2B-VCP, that is compatible with...
Abstract. Volatile chemical products (VCPs) and other non-traditional anthropogenic sources, such as cooking, contribute substantially to the volatile organic compound (VOC) budget in urban areas, but their impact on ozone formation is less certain. This study employs Lagrangian box modeling sensitivity analyses evaluate response sector-specific VOC nitrogen oxide (NOx) emissions two Los Angeles (LA) Basin cities during summer of 2021. The model simulated photochemical processing transport...
Despite decades of emission control measures aimed at improving air quality, Los Angeles (LA) continues to experience severe ozone pollution during the summertime. We incorporate cooking volatile organic compound (VOC) emissions in a chemical transport model and evaluate it against observations order improve representation present-day regime LA. Using this updated model, we investigate impact adopting zero-emission vehicles (ZEVs) on with increased confidence. show that mitigating on-road...
Although some of the physiological mechanisms which contribute to salt tolerance in plants are known, there still major gaps understanding and it remains impossible provide a satisfactory integrated picture for plant as whole. The operation stomata halophytes has received little attention even though all present shoot (apart from that taken during submergence) is thought be carried transpiration stream. In non-halophytes, stomatal function damaged by sodium ions, disruption normal regulation...
Proper display of three-dimensional time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging data complex, nonflat samples requires a correction the in z-direction. Inaccuracies displaying ToF-SIMS arise from projecting surface onto 2D image plane, as well possible variations sputter rate sample being probed. The current study builds on previous studies by creating software written Matlab, ZCorrectorGUI (available at http://mvsa.nb.uw.edu/), to apply z-correction entire 3D sets....
In this study, a non-native chemical species, bromodeoxyuridine (BrdU), was imaged within single HeLa cells using time-of-flight secondary ion mass spectrometry (TOF-SIMS). z-corrected 3D images were reconstructed that accurately portray the distribution of intracellular BrdU as well other structures. The localized to nucleus cells, whereas structures composed CxHyOz– species located in bundles on periphery cells. subcellular features had spatial resolution at or slightly below micrometer...
In this forum we highlight innovative thought, design, and research in the area of interaction design sustainability, illustrating diversity approaches across HCI communities. --- Lisa Nathan Samuel Mann, Editors
Abstract. Formaldehyde (HCHO) is one of the most abundant non-methane volatile organic compounds (VOCs) emitted by fires. HCHO also undergoes chemical production and loss as a fire plume ages, it can be an important oxidant precursor. In this study, we disentangle processes controlling examining its evolution in wildfire plumes sampled NASA DC-8 during Fire Influence on Regional to Global Environments Air Quality experiment (FIREX-AQ) field campaign. 9 12 analyzed plumes, dilution-normalized...
We present a novel method, the Gaussian observational model for edge to center heterogeneity (GOMECH), quantify horizontal chemical structure of plumes. GOMECH fits observations short-lived emissions or products against long-lived tracer (e.g., CO) provide relative metrics plume width (wi/wCO) and (bi/wCO). To validate GOMECH, we investigate OH NO3 oxidation processes in smoke plumes sampled during FIREX-AQ (Fire Influence on Regional Global Environments Air Quality, 2019 wildfire study). An...
Abstract. Iodide chemical ionization mass spectrometry (CIMS) is a common analytical tool used in both laboratory and field experiments to measure large suite of atmospherically relevant compounds. Here, we describe systematic ion molecule reactor (IMR) temperature dependence iodide CIMS analyte sensitivity for wide range analytes experiments. Weakly bound clusters, such as HCl, HONO, HCOOH, HCN, phenol, 2-nitrophenol, acyl peroxynitrate (PAN) detected via the peroxy radical cluster, all...
Lack of recent progress in reducing ground-level ozone (O3) concentrations to comply with health-based standards the South Coast Air Basin (SoCAB) has motivated a reanalysis emission control strategies. Here we used two parallel transportable smog chamber systems measure sensitivity O3 volatile organic compounds (VOCs) and nitrogen oxides (NOx = NO + NO2) Pasadena Redlands, California from July October, 2021. The system measures ambient chemical regime by comparing formation basecase...
Abstract A field study of the tidal and seasonal variations in upland, shoreline, nearshore hydrological processes associated with ground water discharge from unconfined Columbia Aquifer was conducted. The study, performed along a subestuary Chesapeake Bay, involved measurement table elevation, discharge, potentiometric had differentials across sediment‐water interface, salinity. Fresh rates calculated measured gradient using Dupuit assumptions varied 6.1 X 10 ‐3 to 3.8 ‐2 m 3 /day per...