A5008749690- Atmospheric chemistry and aerosols
- Fire effects on ecosystems
- Air Quality and Health Impacts
- Fire dynamics and safety research
- Vehicle emissions and performance
- Toxic Organic Pollutants Impact
- Atmospheric aerosols and clouds
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Catalytic Processes in Materials Science
- Thermochemical Biomass Conversion Processes
- Cyclone Separators and Fluid Dynamics
- Anaerobic Digestion and Biogas Production
- Combustion and flame dynamics
- Advanced Chemical Sensor Technologies
- Granular flow and fluidized beds
- Membrane-based Ion Separation Techniques
- Membrane Separation Technologies
- Rangeland and Wildlife Management
- Electrochemical sensors and biosensors
- Air Quality Monitoring and Forecasting
- Forest Biomass Utilization and Management
- Advanced Aircraft Design and Technologies
- Mineral Processing and Grinding
- Analytical Chemistry and Sensors
University of California, Riverside
2016-2019
Portland State University
2017-2019
University of California, San Diego
2009-2014
Scripps Institution of Oceanography
2009
Abstract. Multiple trace-gas instruments were deployed during the fourth Fire Lab at Missoula Experiment (FLAME-4), including first application of proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOFMS) and comprehensive two-dimensional gas chromatography–time-of-flight (GC × GC-TOFMS) for laboratory biomass burning (BB) measurements. Open-path Fourier transform infrared spectroscopy (OP-FTIR) was also deployed, as well whole-air sampling (WAS) with one-dimensional...
Biomass burning (BB) is a large source of reactive compounds in the atmosphere. While daytime photochemistry BB emissions has been studied some detail, there little focus on nighttime reactions despite potential for substantial oxidative and heterogeneous chemistry. Here, we present first analysis aircraft intercepts agricultural plumes using observations from NOAA WP-3D during 2013 Southeast Nexus (SENEX) campaign. We use these conjunction with detailed chemical box modeling to investigate...
During the summer and fall of 2005 in Riverside, California, seasonal volatility behavior submicrometer aerosol particles was investigated by coupling an automated thermodenuder system to online single-particle mass spectrometer. A strong dependence observed for gas/particle partitioning alkylamines within individual ambient aged organic carbon internally mixed with ammonium, nitrate, sulfate. In summer, amines were strongly correlated nitrate sulfate, suggesting presence aminium sulfate...
Organosulfate species have recently been identified as a potentially significant class of secondary organic aerosol (SOA) species, yet little is known about their behavior in the atmosphere. In this work, organosulfates were observed individual ambient aerosols using single particle mass spectrometry Atlanta, GA during 2002 Aerosol Nucleation and Characterization Experiment (ANARChE) 2008 August Mini-Intensive Gas Study (AMIGAS). Organosulfates derived from biogenically produced isoprene...
Abstract After smoke from burning biomass is emitted into the atmosphere, chemical and physical processes change composition amount of organic aerosol present in aged, diluted plume. During fourth Fire Lab at Missoula Experiment, we performed smog‐chamber experiments to investigate formation secondary (SOA) multiphase oxidation primary (POA). We simulated atmospheric aging a variety fuels while measuring particle using high‐resolution mass spectrometry. quantified SOA tracer ion for...
Abstract. Western US wildlands experience frequent and large-scale wildfires which are predicted to increase in the future. As a result, wildfire smoke emissions expected play an increasing role atmospheric chemistry while negatively impacting regional air quality human health. Understanding impacts of on environment is informed by identifying quantifying chemical compounds that emitted during providing empirical relationships describe how amount composition change based upon different fire...
Abstract Volatile organic compounds (VOCs) emitted from residential wood and crop residue burning were measured in Colorado, U.S. When compared to the emissions burning, exhibited markedly lower concentrations of acetonitrile, a commonly used biomass tracer. For both herbaceous arboraceous fuels, nitrogen‐containing VOCs (NVOCs) strongly depend on fuel nitrogen content; therefore, low NVOC result combustion low‐nitrogen fuel. Consequently, hazardous human health, such as HNCO HCN, formation...
Wildland fires in the western United States are projected to increase frequency, duration, and size. Characterized by widespread diverse conifer forests, burning within this region may lead significant terpenoid emissions. Terpenoids constitute a major class of highly reactive secondary organic aerosol (SOA) precursors, with structure-dependent variability reactivity SOA-formation potential. In study, speciated measurements terpenoids emitted from laboratory prescribed were achieved using...
Organosulfate species have recently gained attention for their potentially significant contribution to secondary organic aerosol (SOA); however, temporal behavior in the ambient atmosphere has not been probed detail. In this work, organosulfates derived from isoprene were observed single particle mass spectra Atlanta, GA during 2002 Aerosol Nucleation and Characterization Experiment (ANARChE) 2008 August Mini-Intensive Gas Study (AMIGAS). Real-time measurements revealed that highest...
Abstract. Biomass-burning organic-aerosol (OA) emissions are known to exhibit semi-volatile behavior that impacts OA loading during plume transport. Because such depends in part on composition, improved speciation of intermediate and organic compounds (I/SVOCs) emitted fires is needed assess the competing effects primary volatilization secondary production. In this study, 18 laboratory were sampled which a range fuel types burned. Emitted I/SVOCs collected onto Teflon filters solid-phase...
Abstract. Secondary organic aerosol (SOA) has been shown to form in biomass-burning emissions laboratory and field studies. However, there is significant variability among studies mass enhancement, which could be due differences fuels, fire conditions, dilution, and/or limitations of experiments observations. This study focuses on understanding processes affecting SOA formation smog-chamber ambient plumes. Vapor wall losses have demonstrated an important factor that can suppress traditional...
Single-particle mass spectrometry (SPMS) has been widely used for characterizing the chemical mixing state of ambient aerosol particles. However, processes occurring during particle ablation and ionization can influence spectra produced by these instruments. These effects remain poorly characterized complex atmospheric During 2005 Study Organic Aerosols in Riverside (SOAR), a thermodenuder was to evaporate more volatile species sequential temperature steps up 230°C; residual particles were...
Abstract. Multiple trace-gas instruments were deployed during the fourth Fire Lab at Missoula Experiment (FLAME-4), including first application of proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOFMS) and comprehensive two-dimensional gas chromatography-time-of-flight (GC×GC-TOFMS) for laboratory biomass burning (BB) measurements. Open-path Fourier-transform infrared spectroscopy (OP-FTIR) was also deployed, as well whole air sampling (WAS) with one-dimensional...
California wildfires are becoming larger and more frequent because of climate change historical fire suppression. The 2017 season was record-breaking in terms monetary damage, area burned, human casualties. In addition, roughly 20 million people were exposed to dense wildfire smoke for days. Understanding the health impacts requires detailed chemical speciation produced from different fuels. This study demonstrates unique fingerprint observed burning manzanita, a common chaparral forest...
Abstract. The current understanding of secondary organic aerosol (SOA) formation within biomass burning (BB) plumes is limited by the incomplete identification and quantification non-methane compounds (NMOCs) emitted from such fires. Gaseous were collected on sorbent cartridges during laboratory burns as part fourth Fire Lab at Missoula Experiment (FLAME-4), with analysis two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC / TOFMS). sensitivity resolving power TOFMS...
Abstract. Western U.S. wildlands experience frequent and large-scale wildfires which are predicted to increase in the future. As a result, wildfire smoke emissions expected play an increasing role atmospheric chemistry while negatively impacting regional air quality human health. Understanding impacts of on environment is informed by identifying quantifying chemical compounds that emitted during providing empirical relationships describe how amount composition change based upon different...
Abstract. Secondary organic aerosol (SOA) has been shown to form in biomass-burning emissions laboratory and field studies. However, there is significant variability among studies mass enhancement, which could be due differences fuels, fire conditions, dilution, and/or limitations of experiments observations. This study focuses on understanding processes affecting SOA formation smog-chamber ambient plumes. Vapor wall losses have demonstrated an important factor that can suppress traditional...
Abstract. Biomass-burning organic-aerosol (OA) emissions are known to exhibit semi-volatile behavior that impacts OA loading during plume transport. Because such depends in part on composition, improved speciation of intermediate and organic compounds (I/SVOCs) emitted fires is needed assess the competing effects primary volatilization secondary production. In this study, we sampled 18 laboratory which a range fuel types were burned. Emitted I/SVOCs collected onto Teflon filters solid-phase...