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Field Measurements of Trace Gases in an Agricultural Region: Identification and Characterization of Aerosol Growth Precursors and Organic Pollutants
Get PDFAtmospheric aerosols affect the climate by influencing radiative forcing and negatively impact human health as pollutants. Trace gases are crucial in the life cycle of atmospheric aerosols, forming aerosols via new particle formation (NPF) and growing aerosols through condensation of low volatility gases. Gas-phase pollutants can partition onto aerosols, exacerbating negative health effects of aerosol exposure and affecting their ability to undergo long-range transport. However, measurements of trace gases in agricultural regions, which account for a large portion of global land use, are limited. This dissertation presents field measurements of trace gases made in the agricultural Southern Great Plains.
In the first study, field measurements of ambient ions made in summer 2016 with an atmospheric pressure interface time-of-flight mass spectrometer are used to characterize trace gases relevant to aerosol formation and growth. A data analysis approach combining binned positive matrix factorization and generalized Kendrick analysis increases the chemical information and temporal resolution available from the dataset. Negative mode ions include clusters of NO3- with highly oxygenated isoprene, monoterpene, and sesquiterpene oxidation products. Sesquiterpene organonitrates dominate the signal of the lowest volatility organic compounds. Positive ion measurements suggest that ammonia and amines are the most abundant bases which may participate in NPF.
Building on the first study, the second study presents measurements made with a nitrate anion chemical ionization mass spectrometer (NO3-CIMS) deployed at SGP in May 2023. NO3-CIMS measurements show that the majority of semi-volatile and low volatility compounds are formed by isoprene and monoterpene oxidation but confirm that the lowest volatility species are formed by sesquiterpene oxidation. Organic nitrates contribute a large fraction of aerosol growth precursors.
The third study presents NO3-CIMS measurements of atmospheric medium-chain chlorinated paraffins (MCCPs), high production volume industrial chemicals which are toxic and ubiquitous environmental pollutants. Few atmospheric measurements of MCCPs have been reported, and current measurements rely on offline techniques with long sample collection times. The high temporal resolution of the NO3-CIMS is used to investigate the behavior of MCCPs in real time and shows that partitioning between aerosols and the gas phase controls the gas-phase MCCP signal.</p
Latin American Newspaper Coverage of Climate Change or Global Warming, 2005-2025 - November 2025
No full textThe Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p
Japanese Newspaper Coverage of Climate Change or Global Warming, 2000-2024 - December 2024
No full textThe Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p
Korean Newspaper Coverage of Climate Change or Global Warming, 2000-2024 - December 2024
No full textThe Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p
Asian Newspaper Coverage of Climate Change or Global Warming, 2004-2025 - May 2025
No full textThe Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p
United Kingdom Newspaper Coverage of Climate Change or Global Warming, 2000-2025 - May 2025
No full textThe Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p
Dialogic Pedagogy microcredential works
Get PDFThis portfolio represents my work from the Critical Dialogic Pedagogy Micro-credential, a 10-week workshop series offered by CU Dialogues at the University of Colorado Boulder. Through a combination of in-person dialogue practice, asynchronous learning, and applied classroom activities, I engaged with core concepts of critical dialogue pedagogy and explored ways to center intersectional equity in my teaching. The micro-credential supported me in deepening my awareness of positionality and power in instructional spaces, and helped me build skills for designing inclusive, dialogically informed learning environments. The artifacts included in this portfolio—such as a positionality statement, lesson redesign, dialogic protocols, and a personal growth reflection—demonstrate my evolving understanding of equity-centered pedagogy and my commitment to fostering dialogue across differences in my role as an educator.</p
Finnish Newspaper Coverage of Climate Change or Global Warming, 2000-2025 - June 2025
No full textThe Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p
Middle Eastern Newspaper Coverage of Climate Change or Global Warming, 2004-2025 - June 2025
No full textThe Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p
North American Newspaper Coverage of Climate Change or Global Warming, 2000-2025 - June 2025
No full textThe Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p
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