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Full-Text Articles in Physical Sciences and Mathematics
Depositional Ice Nucleation On Solid Ammonium Sulfate And Glutaric Acid Particles, K. J. Baustian, M. E. Wise, M. A. Tolbert
Depositional Ice Nucleation On Solid Ammonium Sulfate And Glutaric Acid Particles, K. J. Baustian, M. E. Wise, M. A. Tolbert
CUP Faculty Research
Heterogeneous ice nucleation on solid ammonium sulfate and solid amorphous glutaric acid particles was studied using optical microscopy and Raman spectroscopy. Optical microscopy was used to detect selective nucleation events as water vapor was slowly introduced into an environmental sample cell. Particles that nucleated ice were dried via sublimation and examined in detail using Raman spectroscopy. Depositional ice nucleation occurred preferentially on just a few ammonium sulfate and glutaric acid particles in each sample. For freezing temperatures between 214 K and 235K average ice saturation ratios of S=1.10±0.07 for solid ammonium sulfate and S=1.39±0.16 for solid amorphous glutaric …
Laboratory Studies Of Ice Formation Pathways From Ammonium Sulfate Particles, M. E. Wise, K. J. Baustian, M. A. Tolbert
Laboratory Studies Of Ice Formation Pathways From Ammonium Sulfate Particles, M. E. Wise, K. J. Baustian, M. A. Tolbert
CUP Faculty Research
Cirrus clouds are composed of ice particles and their formation pathways have been studied extensively in the laboratory. The ability of ammonium sulfate particles to act as nuclei for cirrus clouds has been of particular importance because of their ubiquitous presence in the upper troposphere. The results of past laboratory experiments of homogeneous ice nucleation from ammonium sulfate particles show a wide range of freezing conditions. In the present study, a flow tube apparatus equipped with Fourier transform infrared spectroscopy was used to reexamine these discrepancies. It was found that when ammonium sulfate particles were preconditioned at 100% relative humidity …
Hygroscopic Behavior And Liquid-Layer Composition Of Aerosol Particles Generated From Natural And Artificial Seawater, Matthew E. Wise, Evelyn J. Freney, Corey A. Tyree, Jonathan O. Allen, Scot T. Martin, Lynn M. Russell, Peter R. Buseck
Hygroscopic Behavior And Liquid-Layer Composition Of Aerosol Particles Generated From Natural And Artificial Seawater, Matthew E. Wise, Evelyn J. Freney, Corey A. Tyree, Jonathan O. Allen, Scot T. Martin, Lynn M. Russell, Peter R. Buseck
CUP Faculty Research
Sea-salt aerosol (SSA) particles affect the Earth's radiative balance and moderate heterogeneous chemistry in the marine boundary layer. Using conventional and environmental transmission electron microscopes (ETEM), we investigated the hygroscopic growth and liquid-layer compositions of particles generated from three types of aqueous salt solutions: sodium chloride, laboratory-synthesized seawater (S-SSA particles), and natural seawater (N-SSA particles). Three levels of morphological change were observed with the ETEM as the laboratory-generated particles were exposed to increasing relative humidity (RH). The first level, onset of observable morphological changes, occurred on average at 70, 48, and 35% RH for the NaCl, S-SSA, and N-SSA particles, …