{"@context":"http://iiif.io/api/presentation/2/context.json","@id":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/manifest.json","@type":"sc:Manifest","label":"Ice nucleation potential and chemical composition  of laboratory-generated and field-collected organic particles","metadata":[{"label":"dc.description.sponsorship","value":"This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree."},{"label":"dc.format","value":"Monograph"},{"label":"dc.format.medium","value":"Electronic Resource"},{"label":"dc.identifier.uri","value":"http://hdl.handle.net/11401/78266"},{"label":"dc.language.iso","value":"en_US"},{"label":"dcterms.abstract","value":"Ice particles are ubiquitous in the atmosphere, either coexisting with supercooled water droplets in mixed-phase clouds or existing as the sole inhabitant of cirrus clouds.  Aerosol particles act as heterogeneous ice nucleating particles (INPs) and influence ice crystal formation, affecting both cloud radiative properties and climate. Heterogeneous ice nucleation is not a well understood process and is cause for great uncertainty in climate models. Organic aerosol is ubiquitous in the atmosphere. However, the effect organic aerosols on ice nucleation is not well established. This thesis investigates the propensity of organic aerosol to form ice.     Secondary organic aerosol (SOA) particles generated from the OH oxidation of naphthalene, \u03b1-pinene, isoprene, and longifolene serving as surrogates of anthropogenic and biogenic SOA particles with and without the presence of sulfates, as well as \u03b1-pinene SOA coated soot particles, were investigated for their role in atmospheric ice nucleation for both mixed-phase and cirrus clouds conditions. Scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS) analysis was performed to investigate the chemical composition of these particles. Longifolene SOA was the only type of SOA to exist in the solid phase at ambient conditions while the other types appeared liquid-like. Ice nucleation experiments were conducted at temperatures as low as 210 K and biogenic SOA with and without sulfate did not act as INPs under mixed-phase cloud conditions. \u03b1-pinene and longifolene particles did not nucleate ice at relative humidity with respect to ice (RHice) below that required for homogeneous freezing at temperatures above 235 K. The presence of soot in \u03b1-pinene SOA and naphthalene SOA particles could not be unambiguously attributed to promoting ice nucleation at temperatures below ~235 K. However, soot particles can act as INPs for \u03b1-pinene SOA coated soot particles under mixed-phase cloud conditions, while the propensity for soot acting as INP in naphthalene coated soot particles under these conditions remains ambiguous.     Field-collected particles near the city of Manaus in the Amazon rainforest all formed ice below the homogeneous freezing limit for both cirrus and mixed-phase cloud conditions. These INPs induced ice nucleation at similar conditions to those of marine aerosol particles, as well as sharing similar X-ray spectral features with marine aerosol, suggesting that the Amazon INPs are polysaccharidic in nature. Particles collected above and below the rainforest canopy were not preferential in their propensity for ice formation, although the number of pure organic particles collected below the canopy was greater than above.      Field-collected particles from the agricultural Southern Great Plains (SGP) site in Oklahoma all formed ice at conditions above those required for homogeneous freezing. STXM/NEXAFS analysis showed that the INPs were mostly inorganic with a thin organic coating, and the non-INPs were all mostly organic. The presence of this thin organic coating suggests that a thicker organic coating could have possibly deliquesced, thus initiated homogeneous ice nucleation from the aqueous solution. However, laboratory-generated soil particles all formed ice at heterogeneous conditions for both cirrus and mixed phase conditions. These laboratory-generated particles formed ice at similar conditions to Suwanee River fulvic acid (SRFA) particles, suggesting the presence of humic and fluvic acids in the soils initiated ice nucleation.     Atmospheric implications and ice nucleation propensity of these particles are discussed in this thesis. Overall, it is found that organic aerosols cannot be ruled out as potentially important INP in the atmosphere."},{"label":"dcterms.available","value":"2018-06-21T13:38:47Z"},{"label":"dcterms.contributor","value":"Knopf, Daniel"},{"label":"dcterms.creator","value":"Charnawskas, Joseph"},{"label":"dcterms.dateAccepted","value":"2018-06-21T13:38:47Z"},{"label":"dcterms.dateSubmitted","value":"2018-06-21T13:38:47Z"},{"label":"dcterms.description","value":"Department of Marine and Atmospheric Science"},{"label":"dcterms.extent","value":"91 pg."},{"label":"dcterms.format","value":"Monograph"},{"label":"dcterms.identifier","value":"http://hdl.handle.net/11401/78266"},{"label":"dcterms.issued","value":"2017-12-01"},{"label":"dcterms.language","value":"en_US"},{"label":"dcterms.provenance","value":"Made available in DSpace on 2018-06-21T13:38:47Z (GMT). No. of bitstreams: 1\nCharnawskas_grad.sunysb_0771M_13610.pdf: 4481943 bytes, checksum: c6d62d1bd8add5c1d1db3d2ba98e3c08 (MD5)\n  Previous issue date:   12"},{"label":"dcterms.subject","value":"Atmospheric chemistry"},{"label":"dcterms.title","value":"Ice nucleation potential and chemical composition  of laboratory-generated and field-collected organic particles"},{"label":"dcterms.type","value":"Thesis"},{"label":"dc.type","value":"Thesis"}],"description":"This manifest was generated dynamically","viewingDirection":"left-to-right","sequences":[{"@type":"sc:Sequence","canvases":[{"@id":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/canvas/page-1.json","@type":"sc:Canvas","label":"Page 1","height":1650,"width":1275,"images":[{"@type":"oa:Annotation","motivation":"sc:painting","resource":{"@id":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/21%2F44%2F89%2F21448972241689535061359261730660285240/full/full/0/default.jpg","@type":"dctypes:Image","format":"image/jpeg","height":1650,"width":1275,"service":{"@context":"http://iiif.io/api/image/2/context.json","@id":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/21%2F44%2F89%2F21448972241689535061359261730660285240","profile":"http://iiif.io/api/image/2/level2.json"}},"on":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/canvas/page-1.json"}]}]}]}