Lidar and radar studies of turbulence, instabilities, and waves in the Arctic middle atmosphere
Dissertation (Ph.D.) University of Alaska Fairbanks, 2019 This dissertation presents new studies of gravity waves and turbulence in the Arctic middle atmosphere. The studies employ lidars and radar to characterize wave activity, instability and turbulence. In the lidar-based studies, we analyze turb...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/10627 2023-05-15T14:58:12+02:00 Lidar and radar studies of turbulence, instabilities, and waves in the Arctic middle atmosphere Li, Jintai Collins, Richard L. Newman, David E. Simpson, William R. Thorsen, Denise L. Williams, Bifford P. 2019-08 http://hdl.handle.net/11122/10627 en_US eng http://hdl.handle.net/11122/10627 Department of Atmospheric Sciences middle atmosphere arctic regions laser observations atmosphere Dissertation phd 2019 ftunivalaska 2023-02-23T21:37:32Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2019 This dissertation presents new studies of gravity waves and turbulence in the Arctic middle atmosphere. The studies employ lidars and radar to characterize wave activity, instability and turbulence. In the lidar-based studies, we analyze turbulence and wave activity in the MLT based on lidar measurements of atmospheric temperature, density and sodium density, temperature and wind. This combination of measurements provides simultaneous characterization of both the atmospheric stability as well as material transport that allow us to estimate the eddy diffusion coefficient associated with turbulence. We extend the scope of previous studies by developing retrievals of potential temperature and sodium mixing ratio from the Rayleigh density temperature lidar and sodium resonance density lidar measurements. We find that the estimated values of turbulent eddy diffusion coefficients, K, of 400-2800 m²/s, are larger than typically reported (1-1000 m²/s) while the values of the energy dissipation rates, ε, of 5-20 mW/kg, are more typical (0.1-1000 mW/kg). We find that upwardly propagating gravity waves accompany the instabilities. In the presence of instabilities, we find that the gravity waves are dissipating as they propagate upward. We estimate the energy available for turbulence generation from the wave activities and estimate the possible turbulent energy dissipation rate, εGW. We find that the values of εGW are comparable to the values of ε. We find that the estimate of the depth of the layer of turbulence are critical to the estimate of the values of both ε and εGW. We find that our method tends to overestimate the depth, and thus overestimate the value of ε, and underestimate the value of εGW. In the radar-based study, we conduct a retrieval of turbulent parameters in the mesosphere based on a hypothesis test. We distinguish between the presence and absence of turbulence based on fitting Voigt-based and Lorentzian-based line shapes to the radar spectra. We ... Doctoral or Postdoctoral Thesis Arctic Alaska University of Alaska: ScholarWorks@UA Arctic Fairbanks |
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Open Polar |
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University of Alaska: ScholarWorks@UA |
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ftunivalaska |
language |
English |
topic |
middle atmosphere arctic regions laser observations atmosphere |
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middle atmosphere arctic regions laser observations atmosphere Li, Jintai Lidar and radar studies of turbulence, instabilities, and waves in the Arctic middle atmosphere |
topic_facet |
middle atmosphere arctic regions laser observations atmosphere |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 2019 This dissertation presents new studies of gravity waves and turbulence in the Arctic middle atmosphere. The studies employ lidars and radar to characterize wave activity, instability and turbulence. In the lidar-based studies, we analyze turbulence and wave activity in the MLT based on lidar measurements of atmospheric temperature, density and sodium density, temperature and wind. This combination of measurements provides simultaneous characterization of both the atmospheric stability as well as material transport that allow us to estimate the eddy diffusion coefficient associated with turbulence. We extend the scope of previous studies by developing retrievals of potential temperature and sodium mixing ratio from the Rayleigh density temperature lidar and sodium resonance density lidar measurements. We find that the estimated values of turbulent eddy diffusion coefficients, K, of 400-2800 m²/s, are larger than typically reported (1-1000 m²/s) while the values of the energy dissipation rates, ε, of 5-20 mW/kg, are more typical (0.1-1000 mW/kg). We find that upwardly propagating gravity waves accompany the instabilities. In the presence of instabilities, we find that the gravity waves are dissipating as they propagate upward. We estimate the energy available for turbulence generation from the wave activities and estimate the possible turbulent energy dissipation rate, εGW. We find that the values of εGW are comparable to the values of ε. We find that the estimate of the depth of the layer of turbulence are critical to the estimate of the values of both ε and εGW. We find that our method tends to overestimate the depth, and thus overestimate the value of ε, and underestimate the value of εGW. In the radar-based study, we conduct a retrieval of turbulent parameters in the mesosphere based on a hypothesis test. We distinguish between the presence and absence of turbulence based on fitting Voigt-based and Lorentzian-based line shapes to the radar spectra. We ... |
author2 |
Collins, Richard L. Newman, David E. Simpson, William R. Thorsen, Denise L. Williams, Bifford P. |
format |
Doctoral or Postdoctoral Thesis |
author |
Li, Jintai |
author_facet |
Li, Jintai |
author_sort |
Li, Jintai |
title |
Lidar and radar studies of turbulence, instabilities, and waves in the Arctic middle atmosphere |
title_short |
Lidar and radar studies of turbulence, instabilities, and waves in the Arctic middle atmosphere |
title_full |
Lidar and radar studies of turbulence, instabilities, and waves in the Arctic middle atmosphere |
title_fullStr |
Lidar and radar studies of turbulence, instabilities, and waves in the Arctic middle atmosphere |
title_full_unstemmed |
Lidar and radar studies of turbulence, instabilities, and waves in the Arctic middle atmosphere |
title_sort |
lidar and radar studies of turbulence, instabilities, and waves in the arctic middle atmosphere |
publishDate |
2019 |
url |
http://hdl.handle.net/11122/10627 |
geographic |
Arctic Fairbanks |
geographic_facet |
Arctic Fairbanks |
genre |
Arctic Alaska |
genre_facet |
Arctic Alaska |
op_relation |
http://hdl.handle.net/11122/10627 Department of Atmospheric Sciences |
_version_ |
1766330292570685440 |