Physical Sciences and Mathematics Commons^™

Characteristics Of Quasi-Monochromatic Gravity Waves Observed With Na Lidar In The Mesopause Region At Starfire Optical Range, Nm, Xiong Hu, Alan Z. Liu, Chester S. Gardner, Gary R. Swenson

Physical Sciences - Daytona Beach

The University of Illinois Na wind/temperature lidar data collected at the Starfire Optical Range, NM, between Jan. 1998 and May 2000 was used to extract the dominant monochromatic gravity waves. By using simultaneously measured horizontal wind and temperature profiles, the vertical wavelengths (λ_z), (T_I), and propagation directions were determined using the hodograph method. A total of 700 monochromatic gravity waves were analyzed from ~300 h of observations. It was found that 84.4% of the waves were propagating upwards. The mean λ_z was 12.6 km and 9.9 km for upward and downward propagating waves, respectively, and …

A Simulation Study Of Space-Based Observations Of Gravity Waves In The Airglow Using Observed Aloha-93 Wave Parameters, Michael P. Hickey Ph.D., J. S. Brown

Publications

We use gravity wave parameters derived from the ALOHA-93 campaign to model four gravity waves in airglow emissions as observed from the ground to numerically predict whether these waves could have been observed from space. In spite of encountering critical levels, some waves may still be observed in the airglow provided the critical level lies within the airglow emission region. One of the four waves experiences a critical level in the lower region of an airglow layer such that the disturbance to the volume emission rate would be effectively limited to a short distance along a satellite line of sight. …

Photoacoustic Study Of Krf Laser Heating Of Si: Implications For Laser Particle Removal, Sergey I. Kudryashov, Susan D. Allen

Mechanical Engineering - Daytona Beach

A photoacoustic study of KrF laser heating of Si has revealed that the dominant mechanism of acoustic generation is thermoacoustic with a considerable contribution from the concentration-deformation mechanism at laser fluences below the Si melting threshold of 0.5 J/cm ². Upon Si melting the contraction of the molten material contributes significantly to acoustic generation. At fluences above 1.4 J/cm ² laser ablation of the molten layer enhances the amplitude of the compression pulse and diminishes that of the rarefaction pulse. The results of photoacoustic measurements allow optimization of experimental conditions for dry laser particle removal.

© 2002 American Institute …

Removal Versus Ablation In Krf Dry Laser Cleaning Of Polystyrene Particles From Silicon, Sergey I. Kudryashov, Susan D. Allen

Mechanical Engineering - Daytona Beach

Direct absorption and melting of 0.2, 0.5 and 1.1 μm polystyrene particles on a Si substrate irradiated by 248 nm excimer laser radiation was found to contribute to their dry laser removal via a "hopping" mechanism at cleaning thresholds of 0.05, 0.1, and 0.16 J/cm ², respectively. Ablation of these particles, which starts near the beginning of substrate deceleration at fluences above 0.4-0.5 J/cm ², suppresses particle removal due to ablative recoil momentum. At fluences above a second cleaning threshold of 0.7 J/cm ² particles are completely evaporated without any visible surface damage of the Si substrate.

© …

An Observation Of A Fast External Atmospheric Acoustic-Gravity Wave, J. H. Hecht, R. L. Walterscheid, Michael P. Hickey Ph.D., R. J. Rudy, A. Z. Liu

Publications

In November 1999 a new near-IR airglow imaging system was deployed at the Starfire Optical Range outside of Albuquerque, New Mexico. This system allowed wide angle images of the airglow to be collected, with high signal to noise, every 3 seconds with a one second integration time. At approximately 1000 UT on November 17, 1999, a fast wavelike disturbance was seen propagating through the OH Meinel airglow layer. This wave had an observed period of ≈215 seconds, an observed phase velocity of ≈160 m/s and a horizontal wavelength of ≈35 km. This phase velocity is among the fastest yet reported …

High Frequency Gravity Waves Observed In Oh Airglow At Starfire Optical Range, Nm: Seasonal Variations In Momentum Flux, Jing Tang, Alan Z. Liu, Gary R. Swenson

Physical Sciences - Daytona Beach

Airglow imager and Na wind/temperature lidar measurements at Starfire Optical Range, New Mexico (35ºN, 107ºW) are used to estimate the seasonal variation of the vertical fluxes of horizontal momentum carried by high frequency Atmospheric Gravity Waves (AGWs). The cross-correlation coefficients between the vertical and horizontal wind perturbations were calculated from the OH airglow imager data collected during 32 nights in 1998, 1999 and 2000. The RMS wind velocities were deduced from the lidar measurements. The combined information was used to estimate the upper limit of the momentum flux. The meridional component of the vertical flux of horizontal momentum was observed …

Production, Outflow, Velocity, And Radial Distribution Of H2o And Oh In The Coma Of Comet C/1995 O1 (Hale-Bopp) From Wide-Field Imaging Of Oh, Walter M. Harris, Frank Scherb, Edwin Mierkiewicz, Ronald Oliversen, Jeffrey Morgenthaler

Physical Sciences - Daytona Beach

Observations of OH are a useful proxy of the water production rate (Q H2O) and outflow velocity (VH2O) in comets. From wide-field images taken on 1997 March 28 and April 8 that capture the entire scale length of the OH coma of comet C/1995 O1 (Hale-Bopp), we obtain Q OH from the model-independent method of aperture summation and Q H2O from the OH photochemical branching ratio, BROH. Using an adaptive ring summation algorithm, we extract the radial brightness distribution of OH 0-0 band emission out to cometocentric distances of up to 10 to the sixth power km, both as azimuthal …

Further Investigations Of A Mesospheric Inversion Layer Observed In The Aloha-93 Campaign, Tai-Yin Huang, Michael P. Hickey Ph.D., Tai-Fu Tuan

Publications

Temperature and wind data obtained from a Na wind/temperature lidar operated by the University of Illinois group during the Airborne Lidar and Observations of the Hawaiian Airglow (ALOHA-93) Campaign, previously analyzed by Huang et al. [1998] using an isothermal Brunt-Va¨isa¨la¨ frequency, have been reexamined to include temperature gradients in the calculation of the Richardson number. In the previous analysis using the isothermal Brunt-Va¨isa¨la¨ frequency the existence of convective instability could not be assessed. New analysis shows that the nonisothermal Richardson number preserves some features found previously, with some striking differences noticable at times between 0900 and 1030 UT. The nonisothermal …

Coupling Of Coamps And Wavetech With Improved Wave Physics, Shahrdad Sajjadi, Pat Fitzpatrick, Gueorgui Mostovoi, Yongzuo Li, Matt Bettencourt

Publications

The Model Coupling Executable Library (MCEL), developed at the University of Southern Mississippi's Center of Higher Learning, has been successfully used to couple the Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS) and the ocean wave model WAVEWATCH. An example of its application is shown for Hurricane Gordon, showing that two-way coupling results affects boundary layer physics differently than one-way coupling --- in this case, resulting in larger o z and, consequently, larger surface fluxes and a more intense hurricane. However, since analyzing MCEL is difficult because the wave physics is inaccurate, improvements to the wave algorithms are also part of the …

Trends. War On Personality And Personality And War: Comments On Nass And Lee (2002), Ibpp Editor

International Bulletin of Political Psychology

This Trends article discusses another article – Identity and deconstruction, by Clifford Nass and Kwan Min Yee – published in volume 3 (2002) of Archives of Psychiatry & Psychotherapy in which the authors demonstrate that people reliably attribute personality characteristics to computer-synthesized speech, exploring the ramifications in a political psychological context.

Identification Of Cool White Dwarfs In The Noao Deep Wide-Field Survey, M. Kilic, Don E. Winget, T. Von Hippel, C.F. Claver

Publications

The chronology of star formation is recorded in the white dwarf luminosity function (WDLF). White dwarf (WD) structure implies a relatively simple connection between WD luminosity and age. First attempts to exploit WDs as chronometers [3,4,6] showed that the WDLF was a map of the history of star formation in the disk, and a significant shortfall of low-luminosity degenerates–the inevitable consequence of the finite age of the disk. The shortfall near log(L/L⊙)≈−4.5 implies a disk age of 6.5–9.5 Gyr [2]. The WDLF from wide common proper motion binaries [5] does not show the shortfall seen by Liebert et al. (1988). …

Search For Oxygen In Cool Dq White Dwarf Atmospheres, M. Kilic, Ted Von Hippel, D. E. Winget, D. F. Lester, D. Saumon

Publications

The existence of carbon in cool He white dwarf (WD) atmospheres has been known for a relatively long time[5]. The presence of carbon in these atmospheres is explained by convective dredge up of interior carbon [6]. Pelletier et al. (1986) presented the first detailed calculations of this process and showed that carbon diffuses upwards from the core into the base of the He-rich envelope where it can be dredged up by a surface convection zone. As the temperature of the star decreases, more carbon diffuses upward, and the base of convection zone moves deeper into the star, further enriching the …

Wiyn Open Cluster Study. Xi. Wiyn 3.5 Meter Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis

Publications

We present deep BVI observations of the core of M35 and a nearby comparison field obtained at the WIYN 3.5 m telescope under excellent seeing conditions. These observations probe to V > 26 and display the lower main sequence in BV and VI CMDs down to V = 23.3 and 24.6, respectively. At these faint magnitudes the background Galactic field stars are far more numerous than the cluster stars, yet by using a smoothing technique and CMD density distribution subtraction we are able to recover the cluster fiducial main sequence and luminosity function to V = 24.6. We find the location …

Book Review: Neptune: The Planet, Rings And Satellites, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Neptune : the Planet, Rings and Satellites by Ellis D. Miner and Randii R. Wessen Springer/Praxis, 2002 297p, 1-85233-216-6 $44.95

Automated Stellar Spectral Classification And Parameterization For The Masses, Ted Von Hippel, Carlos Allende Prieto, Chris Sneden

Publications

Stellar spectroscopic classification has been successfully automated by a number of groups. Automated classification and parameterization work best when applied to a homogeneous data set, and thus these techniques primarily have been developed for and applied to large surveys. While most ongoing large spectroscopic surveys target extragalactic objects, many stellar spectra have been and will be obtained. We briefly summarize past work on automated classification and parameterization, with emphasis on the work done in our group. Accurate automated classification in the spectral type domain and parameterization in the temperature domain have been relatively easy. Automated parameterization in the metallicity domain, …

Observations Of Persistent Leonid Meteor Trails 3. The ‘‘Glowworm’’, Jack D. Drummond, Brent W. Grime, Chester S. Gardner, Alan Z. Liu, Xinzhao Chu, Michael C. Kelley, Craig Kruschwitz, Timothy J. Kane

Physical Sciences - Daytona Beach

A spectacular, well-observed Leonid meteor of visual magnitude -14.3 appeared on 17 November 1998 and left a lingering trail, dubbed the Glowworm, that was well studied. From a location on Kirtland Air Force Base, near Albuquerque, New Mexico, we obtained CCD images of the trail from 94 to 203 s after the meteor and recorded a video with an intensified camera for even longer. From information obtained with a sodium lidar half an hour after the meteor, we have determined that a gravity wave with a vertical wavelength of 2.4 km was responsible for the right-angled appearance of the trail. …

Metal Abundances And Kinematics Of Bright Metal-Poor Giants Selected From The Lse Survey: Implications For The Metal-Weak Thick Disk, Timothy C. Beers, John S. Drilling, Silvia Rossi, Masashi Chiba, Jaehyon Rhee, Birgit Fṻhrmeister, John E. Norris, Ted Von Hippel

Publications

We report medium-resolution (1–2A ˚ ) spectroscopy and broadband (UBV) photometry for a sample of 39 bright stars (the majority of which are likely to be giants) selected as metal-deficient candidates from an objective-prism survey concentrating on Galactic latitudes below |b| = 30, the Luminous Stars Extension (LSE) survey of Drilling & Bergeron. Although the primary purpose of the LSE survey was to select OB stars (hence the concentration on low latitudes), the small number of bright metal-deficient giant candidates noted during this survey provide interesting information on the metal-weak thick disk (MWTD) population. Metal abundance estimates are obtained from …

Example Of Geospatial Teaching Unit From Eros Class (2002) - Trains, Planes, Autos, And Boats: A Brief History Of Transportation Modes In The Upper Missouri River Valley, Hank Lehrer, Brent D. Bowen

EROS and Other External Training

Native Impact - Native Image and GEM - GPS Workshops - Example of Geospatial Teaching Unit from EROS Class (2002) - Trains, Planes, Autos, and Boats: A Brief History of Transportation Modes in The Upper Missouri River Valley

Extratropical Transition Of Southwest Pacific Tropical Cyclones. Part I: Climatology And Mean Structure Changes, Mark R. Sinclair

Applied Aviation Sciences - Prescott

A database of tropical cyclone best track and intensity information for the southwest Pacific Ocean basin is used to construct a 28-year climatology for tropical cyclones that move into middle latitudes. Of the nine or so tropicalcyclones that form each year, an average of about three can be expected to migrate south of 35°S, with the greatest fraction in March. Storms entering the Tasman Sea west of New Zealand (NZ) move almost due south on average and retain greater intensity than those to the east of NZ, where storms decay quickly while moving rapidly away to the southeast. Storms east …

Comparison Of Na Lidar And Meteor Radar Wind Measurements At Starfire Optical Range, Nm, Usa, Alan Z. Liu, Wayne K. Hocking, Steven J. Franke, T. Thayaparan

Physical Sciences - Daytona Beach

Simultaneous wind measurements in the mesopause region at Starfire Optical Range near Albuquerque, NM with Na wind/temperature lidar and meteor radar have been performed and compared. 20 nights of hourly data recorded with these two instruments at two layers around 86 and 93 km altitude are compared for both zonal and meridional wind components. The mean values are found to have no statistically significant differences. The correlation coefficients vary between 0.63 and 0.70, indicating that the two sets of measurements are broadly consistent. When comparing the averaged variations over the night, the two measurements are highly correlated, with correlation coefficients …

Atmospheric Stability And Gravity Wave Dissipation In The Mesopause Region, Chester S. Gardner, Yucheng Zhao, Alan Z. Liu

Physical Sciences - Daytona Beach

High-resolution temperature profile data collected at the Urbana Atmospheric Observatory (40ºN, 88ºW) and Starfire Optical Range, NM (35ºN, 106.5ºW) with a Na lidar are used to assess the stability of the mesopause region between 80 and 105 km. The mean diurnal and annual temperature profiles demonstrate that in the absence of gravity wave and tidal perturbations, the background atmosphere is statically stable throughout the day and year. Thin layers of instability can be generated only when the combined perturbations associated with tides and gravity waves induce large vertical shears in the horizontal wind and temperature profiles. There is a region …

Laplace Transform Of Spherical Bessel Functions, Andrei Ludu

Andrei Ludu

No abstract provided.

Book Review: The Observing Guide To The Messier Marathon: A Handbook And Atlas, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of The Observing Guide to the Messier Marathon : a Handbook and Atlas by Don Machholz. Cambridge, 2002 157p, 0-521-80386-1 $25.00.

Wiyn Open Cluster Study Xi: Wiyn1 3.5m Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis

Publications

We present deep BV I observations of the core of M35 and a nearby comparison field obtained at the WIYN 3.5m telescope under excellent seeing conditions. These observations probe to V > 26, and display the lower main sequence in BV and V I CMDs down to V = 23.3 and 24.6, respectively. At these faint magnitudes the background Galactic field stars are far more numerous than the cluster stars, yet by using a smoothing technique and CMD density distribution subtraction we are able to recover the cluster fiducial main sequence and luminosity function to V = 24.6. We find the …

Book Review: Flash!: The Hunt For The Biggest Explosions In The Universe, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Flash! : the hunt for the biggest explosions in the universe by Govert Schilling. tr. by Naomi Greenberg-Slovin Cambridge, 2002 291p, 0-521-80053-6 $28.00