A Search For Thermospheric Composition Perturbations Due To Vertical Winds
Dissertation (Ph.D.) University of Alaska Fairbanks, 2006 The thermosphere is generally in hydrostatic equilibrium, with winds blowing horizontally along stratified constant-pressure surfaces, driven by the dayside-to-nightside pressure gradient. A marked change in this paradigm resulted after Spenc...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/8895 2023-05-15T16:55:44+02:00 A Search For Thermospheric Composition Perturbations Due To Vertical Winds Krynicki, Matthew P. Conde, Mark 2006 http://hdl.handle.net/11122/8895 unknown http://hdl.handle.net/11122/8895 Physics Atmospheric Science Optics Atmospheric sciences Thermosphere Thermospheric winds Alaska Poker Flat Northwest Territories Inuvik Dissertation phd 2006 ftunivalaska 2023-04-06T17:53:19Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2006 The thermosphere is generally in hydrostatic equilibrium, with winds blowing horizontally along stratified constant-pressure surfaces, driven by the dayside-to-nightside pressure gradient. A marked change in this paradigm resulted after Spencer et al. [1976] reported vertical wind measurements of 80 m·s-1 from analyses of AE-C satellite data. It is now established that the thermosphere routinely supports large-magnitude (~30-150 m·s-1) vertical winds at auroral latitudes. These vertical winds represent significant departure from hydrostatic and diffusive equilibrium, altering locally---and potentially globally---the thermosphere's and ionosphere's composition, chemistry, thermodynamics and energy budget. Because of their localized nature, large-magnitude vertical wind effects are not entirely known. This thesis presents ground-based Fabry-Perot Spectrometer OI(630.0)-nm observations of upper-thermospheric vertical winds obtained at Inuvik, NT, Canada and Poker Flat, AK. The wind measurements are compared with vertical displacement estimates at ~104 km2 horizontal spatial scales determined from a new modification to the electron transport code of Lummerzheim and Lilensten [1994] as applied to FUV-wavelength observations by POLAR spacecraft's Ultraviolet Imager [Torr et al. , 1995]. The modification, referred to as the column shift, simulates vertical wind effects such as neutral transport and disruption of diffusive equilibrium by vertically displacing the Hedin [1991] MSIS-90 [O2]/[N2] and [O]/([N2]+[O2]) mixing ratios and subsequently redistributing the O, O2, and N 2 densities used in the transport code. Column shift estimates are inferred from comparisons of UVI OI(135.6)-nm auroral observations to their corresponding modeled emission. The modeled OI(135.6)-nm brightness is determined from the modeled thermospheric response to electron precipitation and estimations of the energy flux and characteristic energy of the precipitation, which are inferred ... Doctoral or Postdoctoral Thesis Inuvik Northwest Territories Alaska University of Alaska: ScholarWorks@UA Canada Fairbanks Inuvik ENVELOPE(-133.610,-133.610,68.341,68.341) Northwest Territories |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
unknown |
topic |
Physics Atmospheric Science Optics Atmospheric sciences Thermosphere Thermospheric winds Alaska Poker Flat Northwest Territories Inuvik |
spellingShingle |
Physics Atmospheric Science Optics Atmospheric sciences Thermosphere Thermospheric winds Alaska Poker Flat Northwest Territories Inuvik Krynicki, Matthew P. A Search For Thermospheric Composition Perturbations Due To Vertical Winds |
topic_facet |
Physics Atmospheric Science Optics Atmospheric sciences Thermosphere Thermospheric winds Alaska Poker Flat Northwest Territories Inuvik |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 2006 The thermosphere is generally in hydrostatic equilibrium, with winds blowing horizontally along stratified constant-pressure surfaces, driven by the dayside-to-nightside pressure gradient. A marked change in this paradigm resulted after Spencer et al. [1976] reported vertical wind measurements of 80 m·s-1 from analyses of AE-C satellite data. It is now established that the thermosphere routinely supports large-magnitude (~30-150 m·s-1) vertical winds at auroral latitudes. These vertical winds represent significant departure from hydrostatic and diffusive equilibrium, altering locally---and potentially globally---the thermosphere's and ionosphere's composition, chemistry, thermodynamics and energy budget. Because of their localized nature, large-magnitude vertical wind effects are not entirely known. This thesis presents ground-based Fabry-Perot Spectrometer OI(630.0)-nm observations of upper-thermospheric vertical winds obtained at Inuvik, NT, Canada and Poker Flat, AK. The wind measurements are compared with vertical displacement estimates at ~104 km2 horizontal spatial scales determined from a new modification to the electron transport code of Lummerzheim and Lilensten [1994] as applied to FUV-wavelength observations by POLAR spacecraft's Ultraviolet Imager [Torr et al. , 1995]. The modification, referred to as the column shift, simulates vertical wind effects such as neutral transport and disruption of diffusive equilibrium by vertically displacing the Hedin [1991] MSIS-90 [O2]/[N2] and [O]/([N2]+[O2]) mixing ratios and subsequently redistributing the O, O2, and N 2 densities used in the transport code. Column shift estimates are inferred from comparisons of UVI OI(135.6)-nm auroral observations to their corresponding modeled emission. The modeled OI(135.6)-nm brightness is determined from the modeled thermospheric response to electron precipitation and estimations of the energy flux and characteristic energy of the precipitation, which are inferred ... |
author2 |
Conde, Mark |
format |
Doctoral or Postdoctoral Thesis |
author |
Krynicki, Matthew P. |
author_facet |
Krynicki, Matthew P. |
author_sort |
Krynicki, Matthew P. |
title |
A Search For Thermospheric Composition Perturbations Due To Vertical Winds |
title_short |
A Search For Thermospheric Composition Perturbations Due To Vertical Winds |
title_full |
A Search For Thermospheric Composition Perturbations Due To Vertical Winds |
title_fullStr |
A Search For Thermospheric Composition Perturbations Due To Vertical Winds |
title_full_unstemmed |
A Search For Thermospheric Composition Perturbations Due To Vertical Winds |
title_sort |
search for thermospheric composition perturbations due to vertical winds |
publishDate |
2006 |
url |
http://hdl.handle.net/11122/8895 |
long_lat |
ENVELOPE(-133.610,-133.610,68.341,68.341) |
geographic |
Canada Fairbanks Inuvik Northwest Territories |
geographic_facet |
Canada Fairbanks Inuvik Northwest Territories |
genre |
Inuvik Northwest Territories Alaska |
genre_facet |
Inuvik Northwest Territories Alaska |
op_relation |
http://hdl.handle.net/11122/8895 |
_version_ |
1766046788358242304 |