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Oceanography and Atmospheric Sciences and Meteorology

Embry-Riddle Aeronautical University

2005

Articles 1 - 10 of 10

Full-Text Articles in Physical Sciences and Mathematics

Modification Of Precipitation By Coastal Orography In Storms Crossing Northern California, Curtis N. James, Robert A. Houze Jr. Nov 2005

Modification Of Precipitation By Coastal Orography In Storms Crossing Northern California, Curtis N. James, Robert A. Houze Jr.

Applied Aviation Sciences - Prescott

This study compiles and interprets three-dimensional Weather Surveillance Radar-1988 Doppler (WSR-88D) data during a 2.5-yr period and examines the typical orographic effects on precipitation mainly associated with winter storms passing over coastal northern California.The three-dimensional mean reflectivity patterns show echo structure that was generally stratiform from over the ocean to inland over the mountains. The flow above the 1-km level was strong enough to be unblocked by the terrain, and the mean echo pattern over land had certain characteristics normally associated with an unblocked cross-barrier flow, both on the broad scale of the windward slopes of the coastal mountains and …

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Acoustic Waves Generated By Gusty Flow Over Hilly Terrain, R. L. Walterscheid, Michael P. Hickey Ph.D. Oct 2005

Acoustic Waves Generated By Gusty Flow Over Hilly Terrain, R. L. Walterscheid, Michael P. Hickey Ph.D.

Publications

We examine the generation of acoustic waves by gusty flow over hilly terrain. We use simple theoretical models of the interaction between terrain and eddies and a linear model of acoustic-gravity wave propagation. The calculations presented here suggest that over a dense array of geographically extensive sources orographically generated vertically propagating acoustic waves can be a significant cause of thermospheric heating. This heating may account in good part for the thermospheric hot spot near the Andes reported by Meriwether et al. (1996, 1997).

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Antiphase Oh And Oi Airglow Emissions Induced By A Short-Period Ducted Gravity Wave, Jonathan B. Snively, Victor P. Pasko Apr 2005

Antiphase Oh And Oi Airglow Emissions Induced By A Short-Period Ducted Gravity Wave, Jonathan B. Snively, Victor P. Pasko

Publications

"Numerical simulation of a ducted gravity wave event suggests that OH (8,3) and O(1S) 557.7 nm airglow emissions layers may exhibit opposite-phase intensities when perturbed by a short-period wave undergoing vertical reflection. This effect arises due to the time and temperature dependance of the OH excitation reaction, coupled with the linear polarization properties of vertically-standing waves."

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Physical Processes In Acoustic Wave Heating Of The Thermosphere, G. Schubert, Michael P. Hickey Ph.D., R. L. Walterscheid Apr 2005

Physical Processes In Acoustic Wave Heating Of The Thermosphere, G. Schubert, Michael P. Hickey Ph.D., R. L. Walterscheid

Publications

Upward propagating acoustic waves heat the atmosphere at essentially all heights due to effects of viscous dissipation, sensible heat flux divergence, and Eulerian drift work. Acoustic wave-induced pressure gradient work provides a cooling effect at all heights, but this is overwhelmed by the heating processes. Eulerian drift work and wave-induced pressure gradient work dominate the energy balance, but they nearly cancel at most altitudes, leaving their difference, together with viscous dissipation and sensible heat flux divergence to heat the atmosphere. Acoustic waves are very different from gravity waves which cool the upper atmosphere through the effect of sensible heat flux …

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Rocket-Borne Instrument Design To Observe Peak Oh Meinel Band Vibrational Emission Profiles, Joshua T. Bryson Apr 2005

Rocket-Borne Instrument Design To Observe Peak Oh Meinel Band Vibrational Emission Profiles, Joshua T. Bryson

Master's Theses - Daytona Beach

The effects of density-dependant molecular quenching produce a unique, altitude dependant emission profile of the vibrational emission band for each OH v' value in the mesosphere. Previous rocket flights using broad band sensors have been able to detect a 1-2 km altitude gap between the peak emissions of Av6. An instrument design is presented which will directly measure the individual peak OH vibrational emission altitudes for the v' = 2, 3, 4, 6, 7, and 8 transitions radiating from the mesosphere. This high altitude resolution altitude profile information will enhance the ability to observe vertical propagation of atmospheric gravity waves …

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Characteristics Of Instabilities In The Mesopause Region Over Maui, Hawaii, Feng Li, Alan Z. Liu, Gary R. Swenson Feb 2005

Characteristics Of Instabilities In The Mesopause Region Over Maui, Hawaii, Feng Li, Alan Z. Liu, Gary R. Swenson

Physical Sciences - Daytona Beach

Characteristics of convective and dynamical instabilities in the mesopause region (between 85 and 100 km) over Maui, Hawaii (20.7ºN, 156.3ºW) are investigated using 19 nights, ~133 hours of high-resolution wind and temperature data obtained by the University of Illinois Na wind/temperature lidar during the Maui Mesosphere and Lower Thermosphere (Maui MALT) campaigns. The mean probabilities of convective and dynamical instabilities are observed to be ~3 and 10%, respectively, but there is considerable night-to-night variation. At any given time the probability that an unstable condition is found at some altitudes in the 85–100 km range is 90%. The Maui MALT data …

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Vertical Heat And Constituent Transport In The Mesopause Region By Dissipating Gravity Waves At Maui, Hawaii (20.7ºn), And Starfire Optical Range, New Mexico (35ºn), Alan Z. Liu, Chester S. Gardner Jan 2005

Vertical Heat And Constituent Transport In The Mesopause Region By Dissipating Gravity Waves At Maui, Hawaii (20.7ºn), And Starfire Optical Range, New Mexico (35ºn), Alan Z. Liu, Chester S. Gardner

Physical Sciences - Daytona Beach

Vertical heat flux profiles induced by dissipating gravity waves in the mesopause region (85–100 km altitude) are derived from Na lidar measurements of winds and temperatures at Maui (20.7ºN, 156.3ºW), Hawaii, and compared with earlier results from Starfire Optical Range (SOR, 35.0ºN, 106.5ºW), New Mexico. The heat flux profile at SOR has a single downward maximum of 2.25 ± 0.3 K m/s at 88 km, while the profile at Maui has two downward maxima of 1.25 ± 0.5 K m/s and 1.40 ± 0.5 K m/s at 87 and 95 km, respectively. The common maximum below 90 km can be …

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A Full-Wave Investigation Of The Use Of A ‘‘Cancellation Factor’’ In Gravity Wave–Oh Airglow Interaction Studies, Michael P. Hickey Ph.D., Yonghui Yu Jan 2005

A Full-Wave Investigation Of The Use Of A ‘‘Cancellation Factor’’ In Gravity Wave–Oh Airglow Interaction Studies, Michael P. Hickey Ph.D., Yonghui Yu

Publications

Atmospheric gravity waves (GWs) perturb minor species involved in the chemical reactions of airglow emissions in the upper mesosphere and lower thermosphere. In order to determine gravity wave fluxes and the forcing effects of gravity waves on the mean state (which are proportional to the square of the wave amplitude), it is essential that the amplitude of airglow brightness fluctuation be related to the amplitude of major gas density fluctuation in a deterministic way. This has been achieved through detailed modeling combining gravity wave dynamics described using a full-wave model with the chemistry relevant to the airglow emission of interest. …

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Estimation Of Gravity Wave Momentum Flux With Spectroscopic Imaging, Jing Tang, Farzad Kamalabadi, Steven J. Franke, Alan Z. Liu, Gary R. Swenson Jan 2005

Estimation Of Gravity Wave Momentum Flux With Spectroscopic Imaging, Jing Tang, Farzad Kamalabadi, Steven J. Franke, Alan Z. Liu, Gary R. Swenson

Physical Sciences - Daytona Beach

Atmospheric gravity waves play a significant role in the dynamics and thermal balance of the upper atmosphere. In this paper, we present a novel technique for automated and robust calculation of momentum flux of high-frequency quasi-monochromatic wave components from spectroscopic imaging and horizontal radar wind measurements. Our approach uses the two-dimensional (2-D) cross periodogram of two consecutive Doppler-shifted time-differenced (TD) images to identify wave components and estimate intrinsic wave parameters. Besides estimating the average perturbation of dominant waves in the whole field of view, this technique applies 2-D short-space Fourier transform to the TD images to identify localized wave events. …

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Onset Conditions For Equatorial Spread F Determined During Equis Ii, D. L. Hysell, M. F. Larsen, C. M. Swenson, Aroh Barjatya, T. F. Wheeler, M. F. Sarango, Et.Al Jan 2005

Onset Conditions For Equatorial Spread F Determined During Equis Ii, D. L. Hysell, M. F. Larsen, C. M. Swenson, Aroh Barjatya, T. F. Wheeler, M. F. Sarango, Et.Al

Publications

An investigation into the dynamics and layer structure of the postsunset ionosphere prior to the onset of equatorial spread F (ESF) took place during the NASA EQUIS II campaign on Kwajalein Atoll on August 7 and 15, 2004. On both nights, an instrumented rocket measured plasma number density and vector electric fields to an apogee of about 450 km. Two chemical release rockets were launched both nights to measure lower thermospheric wind profiles. The Altair UHF/VHF radar was used to monitor coherent and incoherent scatter. In both experiments, strong plasma shear flow was detected. Periodic, patchy bottom-type scattering layers were …

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