Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Atmospheric chemistry

Discipline
Institution
Publication Year
Publication
Publication Type
File Type

Articles 1 - 30 of 212

Full-Text Articles in Physical Sciences and Mathematics

Evaluating The Efficiency Of Low-Cost Air Quality Sensors At A Suburban Field Site, Olivia Wuttke Jun 2024

Evaluating The Efficiency Of Low-Cost Air Quality Sensors At A Suburban Field Site, Olivia Wuttke

Undergraduate Theses, Capstones, and Recitals

Science surrounding the use of low-cost sensors (LCS) to monitor air quality is rapidly expanding to satisfy the need to fill in regional air quality data gaps. This project evaluated the suitability of two types of LCS: Modulair-PM and PurpleAir (SD and Flex models) as efficient means to measure airborne particulate matter. The study involved physical installation of nine co-located sensors at a suburban site in Denver, connectivity troubleshooting as necessary, and data analysis/modeling of data over multiple months (19 weeks). PM data was compared between individual sensors of the same type, as well as across the two different sensor …

Go to article

Potentially Massive And Global Non-Pyrogenic Production Of Condensed "Black" Carbon Through Biomass Oxidation, Aleksandar I. Goranov, Hongmei Chen, Jianshu Duan, Satish C. B. Myneni, Patrick G. Hatcher Jan 2024

Potentially Massive And Global Non-Pyrogenic Production Of Condensed "Black" Carbon Through Biomass Oxidation, Aleksandar I. Goranov, Hongmei Chen, Jianshu Duan, Satish C. B. Myneni, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

With the increased occurrences of wildfires worldwide, there has been an increase in scientific interest surrounding the chemistry of fire-derived "black" carbon (BC). Traditionally, wildfire research has assumed that condensed aromatic carbon (ConAC) is exclusively produced via combustion, and thus, ConAC is equated to BC. However, the lack of correlations between ConAC in soils or rivers and wildfire history suggests that ConAC may be produced non-pyrogenically. Here, we show quantitative evidence that this occurs during the oxidation of biomass with environmentally ubiquitous hydroxyl radicals. Pine wood boards exposed to iron nails and natural weather conditions for 12 years yielded a …

Go to article

Data Set For "Atmospheric Aging Of Combustion-Derived Particles: Impact On Stable Free Radical Concentration And Its Ability To Produce Reactive Oxygen Species In Aqueous Media", Brian Majestic, Heather L. Runberg Jan 2023

Data Set For "Atmospheric Aging Of Combustion-Derived Particles: Impact On Stable Free Radical Concentration And Its Ability To Produce Reactive Oxygen Species In Aqueous Media", Brian Majestic, Heather L. Runberg

Chemistry and Biochemistry: Data Sets

Environmentally persistent free radicals (EPFR) are an emerging pollutant found in soot particles. Understanding how these change as they move through the atmosphere is important to human health. Here, soot was generated in the laboratory and exposed to simulated sunlight. The concentrations and characteristics of EPFR in the soot was recorded. Additionally, formation of hydroxyl radical from the photoactivated soot was measured.

Go to article

Infrared Spectra Of Small Radicals For Exoplanetary Spectroscopy: Oh, Nh, Cn, And Ch: The State Of Current Knowledge, Svatopluk Civiš, Adam Pastorek, Martin Ferus, Sergei N. Yurchenko, Noor-Ines Boudjema Jan 2023

Infrared Spectra Of Small Radicals For Exoplanetary Spectroscopy: Oh, Nh, Cn, And Ch: The State Of Current Knowledge, Svatopluk Civiš, Adam Pastorek, Martin Ferus, Sergei N. Yurchenko, Noor-Ines Boudjema

Chemistry & Biochemistry Faculty Publications

In this study, we present a current state-of-the-art review of middle-to-near IR emission spectra of four simple astrophysically relevant molecular radicals—OH, NH, CN and CH. The spectra of these radicals were measured by means of time-resolved Fourier transform infrared spectroscopy in the 700–7500 cm−1 spectral range and with 0.07–0.02 cm−1 spectral resolution. The radicals were generated in a glow discharge of gaseous mixtures in a specially designed discharge cell. The spectra of short-lived radicals published here are of great importance, especially for the detailed knowledge and study of the composition of exoplanetary atmospheres in selected new planets. Today, …

Go to article

The Analysis Of Relationships Between Lightning Strikes And Particulate Matter 2.5 Utilizing Statistical And Numerical Modeling Methods Applied To The 2020 Wildfire Season, Megan Schiede May 2022

The Analysis Of Relationships Between Lightning Strikes And Particulate Matter 2.5 Utilizing Statistical And Numerical Modeling Methods Applied To The 2020 Wildfire Season, Megan Schiede

Atmospheric & Environmental Sciences

Throughout 2020, ambient air pollution was reduced as a result from limiting anthropogenic activities to mitigate the spread of COVID-19. Not all air pollution is created the same as measurements of particulate matter 2.5 (PM2.5) were generally unaffected by this reduction due to PM2.5s source from wildfires. Despite influences from COVID-19 lockdowns, rises in PM2.5 concentrations can be attributed to the anomalously active wildfire season of 2020. As climate change progresses, these extraordinarily active seasons can be classified as the “new normal”; thus, comprehension of such events are vital. Given the ability of lightning to naturally cause wildfires, there exists …

Go to article

Long-Term Trends And Variability Of Pm₂.₅ Mass, Chemical Components, And Sources Over Nys, Hesham Abdelmonem Hassan May 2022

Long-Term Trends And Variability Of Pm₂.₅ Mass, Chemical Components, And Sources Over Nys, Hesham Abdelmonem Hassan

Legacy Theses & Dissertations (2009 - 2024)

Eighteen years of ambient PM2.5 mass and major components are used in this study to harmonize the carbonaceous fraction of PM2.5 data, and to examine long-term trends and seasonal variability changes. The major decreasing trend of PM2.5 mass and major inorganic ions reflects the ambient concentration response to clean air regulations and policies.Although elemental carbon shows a decreasing trend in agreement with most other PM2.5 components, organic carbon shows a different behavior of no-trend to slightly increasing trend in some sites. Organic carbon behavior indicates the growing role of non-combustion sources at the expense of decreasing combustion sources. Seasonal trends …

Go to article

Utah Wintertime Measurements Of Heavy-Duty Vehicle Nitrogen Oxide Emission Factors, Gary A. Bishop, Molly J. Haugen, Brian C. Mcdonald, Adam M. Boies Feb 2022

Utah Wintertime Measurements Of Heavy-Duty Vehicle Nitrogen Oxide Emission Factors, Gary A. Bishop, Molly J. Haugen, Brian C. Mcdonald, Adam M. Boies

Fuel Efficiency Automobile Test Publications

There have only been a few wintertime studies of heavy-duty vehicle (HDV) NOx emissions in the U.S., and while they have observed increased emissions, fleet characterization to identify the cause has been lacking. We have collected wintertime measurements of NOx emission factors from 1,591 HDV at a Utah Port of Entry in December 2020 that includes individual vehicle identification. In general, the NOx emission factors for 2011 & newer chassis model year HDV are significantly higher than 2017 spring measurements from California. The newest chassis model year HDV (2017 - 2021) NOx emission factors are similar …

Go to article

On-Road Vehicle Emission Measurements And Their Use In Evaluating Emission Control Effectiveness {Presentation}, Gary A. Bishop Jan 2022

On-Road Vehicle Emission Measurements And Their Use In Evaluating Emission Control Effectiveness {Presentation}, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Go to article

The Art Of Poetry And Its Place In The History Of The Coordinating Research Councils Real World Emissions Workshop {Poster}, Gary A. Bishop Jan 2022

The Art Of Poetry And Its Place In The History Of The Coordinating Research Councils Real World Emissions Workshop {Poster}, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Go to article

Indoor Air Quality Through The Lens Of Outdoor Atmospheric Chemistry, Jonathan P.D. Abbatt, Douglas B. Collins Jan 2022

Indoor Air Quality Through The Lens Of Outdoor Atmospheric Chemistry, Jonathan P.D. Abbatt, Douglas B. Collins

Faculty Contributions to Books

Outdoor atmospheric chemistry and air quality have been the topic of research that intensified in earnest around the mid-20th century, while indoor air quality research has only been a key focus of chemical researchers over the last 30 years. Examining practices and approaches employed in the outdoor atmospheric chemistry research enterprise provides an additional viewpoint from which we can chart new paths to increase scientific understanding of indoor chemistry. This chapter explores our understanding of primary chemical sources, homogeneous and multiphase reactivity, gas-surface partitioning, and the coupling between the chemistry and dynamics of indoor air through the lens of …

Go to article

On-Road Nox Emissions Evaluation Of The Repair Effectiveness For Recalled Volkswagen Group Light-Duty Diesel Vehicles In The United States, Gary A. Bishop Dec 2021

On-Road Nox Emissions Evaluation Of The Repair Effectiveness For Recalled Volkswagen Group Light-Duty Diesel Vehicles In The United States, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

The admission by the Volkswagen Group in the fall of 2015 that they had duped the United States new vehicle emissions certification testing resulted in perhaps the most expensive violation of U.S. environmental vehicle emission regulations in its history. As part of the subsequent recall of more than 500,000 vehicles in the U.S., owners could sell their vehicles back to the companies or have them repaired. We have used a number of large on-road emission measurement data sets that were routinely collected before and after the recall to evaluate the fuel specific NOx emissions benefit for the vehicles that …

Go to article

Unintended Consequences Of Air Cleaning Chemistry, Douglas B. Collins, Delphine K. Farmer Aug 2021

Unintended Consequences Of Air Cleaning Chemistry, Douglas B. Collins, Delphine K. Farmer

Faculty Journal Articles

Amplified interest in maintaining clean indoor air associated with the airborne transmission risks of SARS-CoV-2 have led to an expansion in the market for commercially available air cleaning systems. While the optimal way to mitigate indoor air pollutants or contaminants is to control (remove) the source, air cleaners are a tool for use when absolute source control is not possible. Interventions for indoor air quality management include physical removal of pollutants through ventilation or collection on filters and sorbent materials, along with chemically reactive processes that transform pollutants or seek to deactivate biological entities. This perspective intends to highlight the …

Go to article

On-Road Remote Sensing Of Automobile Emissions In The Fresno, Ca Area: Spring 2021, Gary A. Bishop Jan 2021

On-Road Remote Sensing Of Automobile Emissions In The Fresno, Ca Area: Spring 2021, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Go to article

Winter Measurements Of Heavy-Duty Vehicles To Characterize The Cold Temperature Effectiveness Of Selective Catalytic Reductions Catalyst In Controlling Oxide Of Nitrogen Emissions, Gary A. Bishop, Molly J. Haugen, Brian C. Mcdonald Jan 2021

Winter Measurements Of Heavy-Duty Vehicles To Characterize The Cold Temperature Effectiveness Of Selective Catalytic Reductions Catalyst In Controlling Oxide Of Nitrogen Emissions, Gary A. Bishop, Molly J. Haugen, Brian C. Mcdonald

Fuel Efficiency Automobile Test Publications

No abstract provided.

Go to article

On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Fall 2020, Gary A. Bishop Jan 2021

On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Fall 2020, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Go to article

Does California’S Emfac2017 Vehicle Emissions Model Under-Predict California Light-Duty Gasoline Vehicle Nox Emissions?, Gary A. Bishop Jan 2021

Does California’S Emfac2017 Vehicle Emissions Model Under-Predict California Light-Duty Gasoline Vehicle Nox Emissions?, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

On-road remote sensing measurements of light and medium-duty gasoline vehicles collected within California’s South Coast Air Basin since 1999 generally fall within the range of observed summer ambient molar NOx/CO measurements collected during morning rush hours. Compared with ambient and on-road emissions, the California Air Resources Board EMFAC model under predicts 2018 gasoline vehicle NOx emission factors by more than a factor of 2.6. Contributing to these differences is that vehicles older than model year 2006 have NOx emission deterioration rates that are up to 4 time’s higher on-road than predicted by the EMFAC model. A …

Go to article

Large Global Variations In Measured Airborne Metal Concentrations Driven By Anthropogenic Sources, Jacob Mcneill, Randal V. Martin, Nofel Lagrosas, 35 Co-Authors Dec 2020

Large Global Variations In Measured Airborne Metal Concentrations Driven By Anthropogenic Sources, Jacob Mcneill, Randal V. Martin, Nofel Lagrosas, 35 Co-Authors

SOSE Affiliate: Manila Observatory

Globally consistent measurements of airborne metal concentrations in fine particulate matter (PM2.5) are important for understanding potential health impacts, prioritizing air pollution mitigation strategies, and enabling global chemical transport model development. PM2.5 filter samples (N ~ 800 from 19 locations) collected from a globally distributed surface particulate matter sampling network (SPARTAN) between January 2013 and April 2019 were analyzed for particulate mass and trace metals content. Metal concentrations exhibited pronounced spatial variation, primarily driven by anthropogenic activities. PM2.5 levels of lead, arsenic, chromium, and zinc were significantly enriched at some locations by factors of 100–3000 compared …

Go to article

Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman Nov 2020

Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman

Chemistry Faculty Publications

This Special Issue provides the first literature collection focused on the development and implementation of unmanned aircraft systems (UAS) and their integration with sensors for atmospheric measurements on Earth. The research covered in the Special Issue combines chemical, physical, and meteorological measurements performed in field campaigns as well as conceptual and laboratory work. Useful examples for the development of platforms and autonomous systems for environmental studies are provided, which demonstrate how careful the operation of sensors aboard UAS must be to gather information for remote sensing in the atmosphere. The work serves as a key collection of articles to introduce …

Go to article

Preliminary Quantitative And Qualitative Investigations On The Heterogeneous, Irreversible Uptake Of Acetone By Titanium(Iv) Oxide, John S. André, Natalie Eskandary, Terry Franklin, Emilia J. Mccann, Oscar Pascual-Diaz, Gregory M. Pitch, Jesus D. Rincon, Megan N. Wright, Christopher W. Harmon Oct 2020

Preliminary Quantitative And Qualitative Investigations On The Heterogeneous, Irreversible Uptake Of Acetone By Titanium(Iv) Oxide, John S. André, Natalie Eskandary, Terry Franklin, Emilia J. Mccann, Oscar Pascual-Diaz, Gregory M. Pitch, Jesus D. Rincon, Megan N. Wright, Christopher W. Harmon

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Go to article

Essays On Environmental And Health Economics., Prachi Singh Dr. Oct 2020

Essays On Environmental And Health Economics., Prachi Singh Dr.

Doctoral Theses

This thesis consists of three empirical essays that investigate issues in environmental and health economics. The main focus of this thesis is to study how environmental degradation or interventions in this domain can affect demographic and health outcomes of the population in developing countries. The first chapter explores the effect of an information campaign about arsenic contamination in Bangladesh on marriage market outcomes. This study finds that providing information about negative effects of arsenic consumption had an unintended consequence in the marriage market. Specifically, information about lower fertility, skin lesions, cancers and higher mortality related to arsenic exposure induced individuals …

Go to article

Iron Speciation In Pm2.5 From Urban, Agriculture, And Mixed Environments In Colorado, Usa, Joseph R. Salazar, David J. Pfotenhauer, Frank Leresche, Fernando L. Rosario-Ortiz, Michael P. Hannigan, Sirine C. Fakra, Brian Majestic Oct 2020

Iron Speciation In Pm2.5 From Urban, Agriculture, And Mixed Environments In Colorado, Usa, Joseph R. Salazar, David J. Pfotenhauer, Frank Leresche, Fernando L. Rosario-Ortiz, Michael P. Hannigan, Sirine C. Fakra, Brian Majestic

Chemistry and Biochemistry: Faculty Scholarship

Atmospheric iron solubility varies depending on whether the particles are collected in rural or urban areas, with urban areas showing increased iron solubility. In this study, we investigate if the iron species present in different environments affects its ultimate solubility. Field data are presented from the Platte River Air Pollution and Photochemistry Experiment (PRAPPE), aimed at understanding the interactions between organic carbon and trace elements in atmospheric particulate matter (PM). 24-hr PM2.5 samples were collected during the summer and winter (2016–2017), at three different sites on the Eastern Colorado plains: an urban, agricultural, and a mixed site. Downtown Denver had …

Go to article

Mapping Jupiter's Mischief, Channon Visscher Jun 2020

Mapping Jupiter's Mischief, Channon Visscher

Faculty Work Comprehensive List

New results (Grassi et al., 2020, https://doi.org/10.1029/2019JE006206) from analysis of Juno Jovian Infrared Auroral Mapper (JIRAM) 4‐ to 5‐μm observations provide updated latitudinal abundance profiles and measurements of the spatial distribution of H2O, NH3, PH3, GeH4, and AsH3 in Jupiter's troposphere near the 3‐ to 5‐bar level. The observed compositional variations provide new constraints on processes shaping chemical abundances in the cloud‐forming region of the troposphere, including vertical and horizontal atmospheric mixing, meteorology and cloud formation, transport‐induced quenching, and photochemistry. Along with recent results from the Juno Microwave Radiometer (MWR) for NH3 and H2O abundances far below the clouds, the …

Go to article

Computation Of Atmospheric Concentrations Of Molecular Clusters From Ab Initio Thermochemistry, Tuguldur T. Odbadrakh, Ariel G. Gale, Benjamin T. Ball, Berhane Temelso, George C. Shields Apr 2020

Computation Of Atmospheric Concentrations Of Molecular Clusters From Ab Initio Thermochemistry, Tuguldur T. Odbadrakh, Ariel G. Gale, Benjamin T. Ball, Berhane Temelso, George C. Shields

Chemistry Publications

The computational study of the formation and growth of atmospheric aerosols requires an accurate Gibbs free energy surface, which can be obtained from gas phase electronic structure and vibrational frequency calculations. These quantities are valid for those atmospheric clusters whose geometries correspond to a minimum on their potential energy surfaces. The Gibbs free energy of the minimum energy structure can be used to predict atmospheric concentrations of the cluster under a variety of conditions such as temperature and pressure. We present a computationally inexpensive procedure built on a genetic algorithm-based configurational sampling followed by a series of increasingly accurate screening …

Go to article

Global Pattern And Change Of Cropland Soil Organic Carbon During 1901-2010: Roles Of Climate, Atmospheric Chemistry, Land Use And Management, Wei Ren, Kamaljit Banger, Bo Tao, Jia Yang, Yawen Huang, Hanqin Tian Mar 2020

Global Pattern And Change Of Cropland Soil Organic Carbon During 1901-2010: Roles Of Climate, Atmospheric Chemistry, Land Use And Management, Wei Ren, Kamaljit Banger, Bo Tao, Jia Yang, Yawen Huang, Hanqin Tian

Plant and Soil Sciences Faculty Publications

Soil organic carbon (SOC) in croplands is a key property of soil quality for ensuring food security and agricultural sustainability, and also plays a central role in the global carbon (C) budget. When managed sustainably, soils may play a critical role in mitigating climate change by sequestering C and decreasing greenhouse gas emissions into the atmosphere. However, the magnitude and spatio-temporal patterns of global cropland SOC are far from well constrained due to high land surface heterogeneity, complicated mechanisms, and multiple influencing factors. Here, we use a process-based agroecosystem model (DLEM-Ag) in combination with diverse spatially-explicit gridded environmental data to …

Go to article

Water-Mediated Peptide Bond Formation In The Gas Phase: A Model Prebiotic Reaction, George C. Shields, Ariel Gale, Tuguldur T. Odbadrakh, Tyler Ball Jan 2020

Water-Mediated Peptide Bond Formation In The Gas Phase: A Model Prebiotic Reaction, George C. Shields, Ariel Gale, Tuguldur T. Odbadrakh, Tyler Ball

Chemistry Publications

The emergence of life on the prebiotic Earth must have involved the formation of polypeptides, yet the polymerization of amino acids is thermodynamically unfavorable under biologically relevant aqueous conditions because amino acids are zwitterions in solution and because of the production of a water molecule through a condensation reaction. Many mechanisms for overcoming this thermodynamic unfavorability have been proposed, but the role of gas phase water clusters has not been investigated. We present the thermodynamics of the water-mediated gas phase dimerization reaction of glycine as a model for the atmospheric polymerization of amino acids prior to the emergence of biological …

Go to article

On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Winter 2020, Gary A. Bishop Jan 2020

On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Winter 2020, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Go to article

On-Road Remote Sensing Of Automobile Emissions In The Tulsa Area: Fall 2019, Gary A. Bishop Jan 2020

On-Road Remote Sensing Of Automobile Emissions In The Tulsa Area: Fall 2019, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Go to article

Are Electric Vehicles A Panacea For Reducing Ozone Precursor Emissions?, Gary A. Bishop Jan 2020

Are Electric Vehicles A Panacea For Reducing Ozone Precursor Emissions?, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Go to article

Vehicle Exhaust Remote Sensing Device Method To Screen Vehicles For Evaporative Running Loss Emissions, Gary A. Bishop, Timothy H. Defries, James A. Sidebottom, James M. Kemper Jan 2020

Vehicle Exhaust Remote Sensing Device Method To Screen Vehicles For Evaporative Running Loss Emissions, Gary A. Bishop, Timothy H. Defries, James A. Sidebottom, James M. Kemper

Fuel Efficiency Automobile Test Publications

Vehicle hydrocarbon (HC) emissions can be emitted from either tailpipe or non-tailpipe locations and understanding their fleet apportionment is important for successful air pollution policy. Vehicles initially misidentified as having elevated tailpipe HC emissions first indicated that roadside exhaust sensors could detect the presence of evaporative HC emissions as increased noise in the HC/carbon dioxide (CO2) correlation measurement. The 90th percentile of the largest residual of the HC/CO2 correlation is defined as a running loss index (RLI) for each measurement. An RLI that is three standard deviations or greater above the instruments noise indicates possible evaporative …

Go to article

Inspection And Maintenance Evaluation Using Historical U.S. Remote Sensing Measurements, Gary A. Bishop Jan 2020

Inspection And Maintenance Evaluation Using Historical U.S. Remote Sensing Measurements, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Go to article

Next Last