Atmospheric Sciences Commons^™

Establishment Of A Research Site At The Kennedy Mountain Campus For The Observation Of Airborne Particulate Matter, Alyssa Knaus

Undergraduate Theses, Capstones, and Recitals

This thesis explored particulate matter (PM) concentrations at two sites within the Colorado Front Range. The study utilized two models of PurpleAir PM sensors, Flex and SD-II, to provide real-time, accessible data on PM1, PM2.5, and PM10 mass concentrations with the goal of establishing the first research site at the Kennedy Mountain Campus (KMC). The first of the two sites used during this study was at a suburban location outside of Denver, CO. This period was used as an instrument intercomparison period in order to conduct instrument analysis. The initial findings from this period found significant correlations between PM concentration …

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 …

Improved Characterization And Analysis Strategies For Uv-Lif Bioaerosol Instrumentation: Lab And Field Application, Nicole Justine Savage

Electronic Theses and Dissertations

Atmospheric particles of biological origin, also referred to as bioaerosols or primary biological aerosol particles (PBAP), are important to various human health and environmental systems. There has been a recent steep increase in the frequency of published studies utilizing commercial instrumentation based on ultraviolet laser/light-induced fluorescence (UV-LIF), such as the WIBS (wideband integrated bioaerosol sensor), for bioaerosol detection both outdoors and in the built environment. Significant work over several decades supported the development of these technologies, but efforts to systematically characterize the operation of new commercial sensors has remained lacking. Specifically, there are gaps in the understanding of how different …

Quantification Of Airborne Fungal Spores Comparing Molecular Tracers Via Ion Chromatography And Uv-Lif Methods, Marie Ila Gosselin

Electronic Theses and Dissertations

Fungal spores represent an understudied subcategory of bioaerosols that can impact human health as pathogenic and allergenic particles. Fungal spores also have been shown to act as effective ice nuclei and giant cloud condensation nuclei in some cases. This has implications on the hydrological cycle on local and regional scales by impacting the formation and evolution of clouds and precipitation. The quantification of fungal spores has been limited in the past due to methods that were costly and that suffered from poor time resolution. The most commonly applied methods for airborne fungal spore analysis have traditionally included microscopy and culturing, …

New Particle Formation In The Mid-Latitude Upper Troposphere, Duncan Axisa

Electronic Theses and Dissertations

Primary aerosol production due to new particle formation (NPF) in the upper troposphere and the impact that this might have on cloud condensation nuclei (CCN) concentration can be of sufficient magnitude to contribute to the uncertainty in radiative forcing. This uncertainty affects our ability to estimate how sensitive the climate is to greenhouse gas emissions. Therefore, new particle formation must be accurately defined, parametrized and accounted for in models.

This research involved the deployment of instruments, data analysis and interpretation of particle formation events during the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) campaign. The approach combined field measurements and observations …

A Model Of The Effects Of Deforestation On Local Climate In The North Cascades, Monica R. H. Jasper

Geography and the Environment: Graduate Student Capstones

Changes in areal extent of land cover types may lead to alterations in the surface energy budget that contribute to anthropogenic climate forcing. This study examines the effects of deforestation in the Cascade Range on local temperature. Temperature sensors were installed in 14 forest stands, taking measurements for one year. Estimated tree age, circumference, and species were recorded to calculate stand density index. Satellite imagery was used to calculate shade fraction from spectral mixture analysis, which is a proxy for canopy structure and density. These data were used to construct seasonal cycles of temperature to model variation with stand density …

Source Apportionment Of Atmospheric Particulate Matter In Developing Countries Using Trace Elements And Stable Metal Isotope Ratios, Nitika Dewan

Electronic Theses and Dissertations

The work presented herein details the source apportionment of atmospheric particulate matter in developing countries (Kyrgyzstan in Central Asia, metropolitan cities in Northern India, and Shenzhen in China) using trace elements and stable metal isotope ratios. The first study focused on the development of a novel method for the concomitant separation of rare-earth elements in environmental samples of any geological origin. The separation procedure is based on three extraction chromatographic materials, referred to as Sr.Spec, TRU.Spec, and Ln.Spec. This triple column arrangement enables the simultaneous isolation of pure Sr and Nd fractions in less than one day and with great …

The Micro-Orifice Uniform Deposit Impactor–Droplet Freezing Technique (Moudi-Dft) For Measuring Concentrations Of Ice Nucleating Particles As A Function Of Size: Improvements And Initial Validation, R. H. Mason, C. Chou, C. S. Mccluskey, E. J. T. Levin, C. L. Schiller, T. C. J. Hill, J. Alex Huffman, P. J. Demott, A. K. Bertram

Chemistry and Biochemistry: Faculty Scholarship

The micro-orifice uniform deposit impactor– droplet freezing technique (MOUDI-DFT) combines particle collection by inertial impaction (via the MOUDI) and a microscope-based immersion freezing apparatus (the DFT) to measure atmospheric concentrations of ice nucleating particles (INPs) as a function of size and temperature. In the first part of this study we improved upon this recently introduced technique. Using optical microscopy, we investigated the non-uniformity of MOUDI aerosol deposits at spatial resolutions of 1, 0.25 mm, and for some stages when necessary 0.10 mm. The results from these measurements show that at a spatial resolution of 1mm and less, the concentration of …

Regional-Scale Simulations Of Fungal Spore Aerosols Using An Emission Parameterization Adapted To Local Measurements Of Fluorescent Biological Aerosol Particles, Matthias Hummel, Corinna Hoose, M. Gallagher, D. A. Healy, J. Alex Huffman, D. O'Connor, U. Pöschl, C. Pöhlker, N. H. Robinson, M. Schnaiter, J. R. Sodeau, M. Stengel, E. Toprak, H. Vogel

Chemistry and Biochemistry: Faculty Scholarship

Fungal spores as a prominent type of primary biological aerosol particles (PBAP) have been incorporated into the COSMO-ART (Consortium for Small-scale Modelling- Aerosols and Reactive Trace gases) regional atmospheric model. Two literature-based emission rates for fungal spores derived from fungal spore colony counts and chemical tracer measurements were used as a parameterization baseline for this study. A third, new emission parameterization for fluorescent biological aerosol particles (FBAP) was adapted to field measurements from four locations across Europe. FBAP concentrations can be regarded as a lower estimate of total PBAP concentrations. Size distributions of FBAP often show a distinct mode at …