A full‐wave model for a binary gas thermosphere: Effects of thermal conductivity and viscosity

Hickey, Michael P.; Walterscheid, R. L.; Schubert, G.

doi:10.1002/2014ja020583

Cited by 19 publications

(20 citation statements)

References 15 publications

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“…Since there are relatively few observations or modeling studies of this region, comparisons of this amplitude with other work are scarce. Our perturbations are somewhat smaller than those used by Hickey et al () and in line with the relative perturbations found by Chen et al () Becker and Vadas () for the 90–110 km altitude ranges.…”

Section: Methodssupporting

confidence: 92%

Modeled Gravity Wave‐Like Perturbations in the Brightness of Far Ultraviolet Emissions for the GOLD Mission

et al. 2018

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The NASA Global‐scale Observations of Limb and Disk (GOLD) mission will study the coupling of the thermosphere with the lower atmosphere through an examination of temperature and composition, allowing the study of atmospheric waves. A key mechanism of energy and momentum transport between atmospheric regions is gravity waves. GOLD is an imaging spectrograph that will measure Earth's airglow emissions (both nightglow and dayglow) in the far ultraviolet range from 132 to 162 nm, including the atomic oxygen doublet at 135.6 nm and molecular nitrogen Lyman‐Birge‐Hopfield bands. GOLD will be the first instrument to make such measurements from the perspective of a geostationary orbit, which creates unique challenges and opportunities for observing atmospheric waves. Here we model the ability of the GOLD imager to detect a gravity wave‐like perturbation from the emergent brightness variations using a combination of a general circulation model and a model of the thermospheric airglow in the far ultraviolet. A 10% perturbation in temperature (±59 K at 150 km) and constituent densities is introduced into the vertical columns of the atmosphere, which results in a ±1.5 Rayleigh perturbation to the brightness of both spectral features, with the same wave period as the introduced perturbation. For the expected total signal, particle background counts, and chosen spectral feature, signal‐to‐noise calculations indicate that integration for several minutes will allow gravity wave perturbations to be observed in brightness perturbations on a single pixel of an image.

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Section: Methodssupporting

confidence: 92%

Modeled Gravity Wave‐Like Perturbations in the Brightness of Far Ultraviolet Emissions for the GOLD Mission

et al. 2018

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“…Additionally, dissipation altitudes predicted by these preliminary simulations agree with the results reported here and are consistent with the upper bound reported in Smith et al [] that the waves dissipate by 400 km. These preliminary simulations are also consistent with predictions of the spectral full‐wave model of H09, which models effects due to variable atmospheric composition with the inclusion of a vertically varying mean molecular weight obtained from the Mass Spectrometer Incoherent Scatter (MSIS) model [ Hedin , ] and has been employed to explicitly examine the one‐gas approximation in the context of wave‐induced changes in composition [ Walterscheid and Hickey , ] and the implications of a binary gas thermosphere on viscosity and thermal conductivity [ Hickey et al ., ], which found that those effects become significant only above ~250 km.…”

Section: Discussionmentioning

confidence: 99%

Tsunami‐driven gravity waves in the presence of vertically varying background and tidal wind structures

2017

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Many characteristics of tsunami‐driven gravity waves (TDGWs) enable them to easily propagate into the thermosphere and ionosphere with appreciable amplitudes capable of producing detectable perturbations in electron densities and total electron content. The impact of vertically varying background and tidal wind structures on TDGW propagation is investigated with a series of idealized background wind profiles to assess the relative importance of wave reflection, critical‐level approach, and dissipation. These numerical simulations employ a 2‐D nonlinear anelastic finite‐volume neutral atmosphere model which accounts for effects accompanying vertical gravity wave (GW) propagation such as amplitude growth with altitude. The GWs are excited by an idealized tsunami forcing with a 50 cm sea surface displacement, a 400 km horizontal wavelength, and a phase speed of 200 ms−1 consistent with previous studies of the tsunami generated by the 26 December 2004 Sumatra earthquake. Results indicate that rather than partial reflection and trapping, the dominant process governing TDGW propagation to thermospheric altitudes is refraction to larger and smaller vertical scales, resulting in respectively larger and smaller vertical group velocities and respectively reduced and increased viscous dissipation. Under all considered background wind profiles, TDGWs were able to attain ionospheric altitudes with appreciable amplitudes. Finally, evidence of nonlinear effects is observed and the conditions leading to their formation is discussed.

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“…Other researchers compared TEC results with the state-of-the-art Embry-Riddle Aeronautical University (ERAU) model [Snively, 2013;Heale and Snively, 2015;Zettergren and Snively, 2015;Hickey et al, 2015], and they found a good agreement between the ERAU model and acoustic-wave-generated TEC perturbations.…”

Section: 1002/2015rs005910mentioning

confidence: 99%

Review and perspectives: Understanding natural‐hazards‐generated ionospheric perturbations using GPS measurements and coupled modeling

et al. 2016

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Natural hazards including earthquakes, volcanic eruptions, and tsunamis have been significant threats to humans throughout recorded history. Global navigation satellite systems (GNSS; including the Global Positioning System (GPS)) receivers have become primary sensors to measure signatures associated with natural hazards. These signatures typically include GPS‐derived seismic deformation measurements, coseismic vertical displacements, and real‐time GPS‐derived ocean buoy positioning estimates. Another way to use GPS observables is to compute the ionospheric total electron content (TEC) to measure, model, and monitor postseismic ionospheric disturbances caused by, e.g., earthquakes, volcanic eruptions, and tsunamis. In this paper, we review research progress at the Jet Propulsion Laboratory and elsewhere using examples of ground‐based and spaceborne observation of natural hazards that generated TEC perturbations. We present results for state‐of‐the‐art imaging using ground‐based and spaceborne ionospheric measurements and coupled atmosphere‐ionosphere modeling of ionospheric TEC perturbations. We also report advancements and chart future directions in modeling and inversion techniques to estimate tsunami wave heights and ground surface displacements using TEC measurements and error estimates. Our initial retrievals strongly suggest that both ground‐based and spaceborne GPS remote sensing techniques could play a critical role in detection and imaging of the upper atmosphere signatures of natural hazards including earthquakes and tsunamis. We found that combining ground‐based and spaceborne measurements may be crucial in estimating critical geophysical parameters such as tsunami wave heights and ground surface displacements using TEC observations. The GNSS‐based remote sensing of natural‐hazard‐induced ionospheric disturbances could be applied to and used in operational tsunami and earthquake early warning systems.

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A full‐wave model for a binary gas thermosphere: Effects of thermal conductivity and viscosity

Cited by 19 publications

References 15 publications

Modeled Gravity Wave‐Like Perturbations in the Brightness of Far Ultraviolet Emissions for the GOLD Mission

Modeled Gravity Wave‐Like Perturbations in the Brightness of Far Ultraviolet Emissions for the GOLD Mission

Tsunami‐driven gravity waves in the presence of vertically varying background and tidal wind structures

Review and perspectives: Understanding natural‐hazards‐generated ionospheric perturbations using GPS measurements and coupled modeling

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