Dissertation
Biomass burning photochemistry: radicals and radical precursors
Doctor of Philosophy (Ph.D.), Drexel University
Jan 2023
DOI:
https://doi.org/10.17918/00001440
Abstract
Wildfires emit particulate matter, nitrogen oxides (NOx = NO + NO2), and a multitude of volatile organic compounds (VOCs). As biomass burning plumes transport downwind, these emissions are photochemically processed and produce secondary pollutants (e.g., ozone (O3) and secondary organic aerosol). The radicals that process these emissions - the hydroxyl radical (OH) and peroxy radicals (HO2 + RO2) - have been historically understudied within biomass burning influenced settings. Our research group utilized a novel peroxy radical sensor ECHAMP (Ethane CHemical AMPlifier) to measure concentrations of total peroxy radicals in several aged biomass burning plumes that were sampled as part of a collaborative field project based in McCall, Idaho, in August 2018. These measurements, combined with those of many other compounds, allow us to gain unique insights into radical photochemistry and ozone formation in air influenced by biomass burning. Measured peroxy radical concentrations also allowed for the assessment of the chemistry mechanisms employed by chemical box models. More recent work has involved measurements of biomass burning relevant compounds by chemical ionization mass spectrometry (CIMS). This includes nitrous acid (HONO) which acts as a dominant radical precursor in freshly emitted biomass burning plumes and hydrogen cyanide (HCN) - a commonly used biomass burning tracer. This CIMS work has mainly focused on (1) development of a new photolytic HONO calibration method and (2) field measurements near Boise, Idaho, in August 2019.
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Details
- Title
- Biomass burning photochemistry
- Creators
- Andrew John Lindsay
- Contributors
- Ezra Wood (Advisor)
- Awarding Institution
- Drexel University
- Degree Awarded
- Doctor of Philosophy (Ph.D.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- xii, 207 pages
- Resource Type
- Dissertation
- Language
- English
- Academic Unit
- College of Arts and Sciences; Chemistry; Drexel University
- Other Identifier
- 991020034414604721