Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Publications

Discipline
Institution
Keyword
Publication Year
Publication Type
File Type

Articles 4351 - 4380 of 5032

Full-Text Articles in Entire DC Network

The Diffuse Gamma-Ray Background From Supernovae, Dieter H. Hartmann, K. Watanabe, M. D. Leising, L.-S. The Nov 1998

The Diffuse Gamma-Ray Background From Supernovae, Dieter H. Hartmann, K. Watanabe, M. D. Leising, L.-S. The

Publications

The diffuse extragalactic γ-ray background in the MeV region is believed to be due to photons from radioactivity produced in supernovae throughout the history of galaxies in the universe. In particular, γ-ray line emission from the decay chain 56Ni → 56Co → 56Fe provides the dominant photon source (Clayton & Silk 1969). Although iron synthesis occurs in all types of supernovae, the contribution to the background is dominated by Type Ia events due to their higher photon escape probabilities. Estimates of the star formation history in the universe suggest a rapid increase by a factor ∼ 10 from the present …

Go to article

A Statistical Treatment Of The Gamma-Ray Burst "No Host Galaxy" Problem: Ii. Energies Of Standard Candle Bursts, Dieter H. Hartmann, David L. Band, Bradley E. Schaefer Nov 1998

A Statistical Treatment Of The Gamma-Ray Burst "No Host Galaxy" Problem: Ii. Energies Of Standard Candle Bursts, Dieter H. Hartmann, David L. Band, Bradley E. Schaefer

Publications

With the discovery that the afterglows after some bursts are coincident with faint galaxies, the search for host galaxies is no longer a test of whether bursts are at cosmological distances, but rather a test of particular cosmological models. The methodology we developed to investigate the original “no host galaxy” problem is equally valid for testing different cosmological models, and is applicable to the galaxies coincident with optical transients. We apply this methodology to a family of models where we vary the total energy of standard candle bursts. We find that total isotropic energies of E < 2 ×10^52 erg are ruled out while E ∼ 10^53 erg is favored.

Go to article

Detection Of Silver In Metal-Poor Stars, James L. Crawford, Christopher Sneden, Jeremy R. King, Ann M. Boesgaard, Contantine P. Deliyannis Nov 1998

Detection Of Silver In Metal-Poor Stars, James L. Crawford, Christopher Sneden, Jeremy R. King, Ann M. Boesgaard, Contantine P. Deliyannis

Publications

The resonance lines of neutral silver appearing at 3280, 3382 Å in the near-ultraviolet spectral region have been identified on Keck I HIRES spectra of four halo stars with metallicities -1.3 ≥ [Fe/H] ≥ -2.2. This represents the first detection in metal-poor stars of an element in the atomic number range 41 ≤ Z ≤ 55. The mean relative silver abundance is [Ag/Fe] +0.2, with little star-to-star variation. Silver abundance upper limits in three other metal-poor stars are consistent with this mean value. The modest overabundance of silver is similar to the overabundances in this metallicity range exhibited by other …

Go to article

Competition Between Larval Fishes In Reservoirs: The Role Of Relative Timing Of Appearance, James E. Garvey, Roy A. Stein Nov 1998

Competition Between Larval Fishes In Reservoirs: The Role Of Relative Timing Of Appearance, James E. Garvey, Roy A. Stein

Publications

In small, hypereutrophic reservoirs (<100 ha; >100 mg total phosphorus/L), larval gizzard shad Dorosoma cepedianum and threadfin shad D. petenense (henceforth, shad) reach high densities in the limnetic zone, virtually eliminate zooplankton, and perhaps compromise success of other planktivorous larvae, such as bluegill Lepomis macrochirus. Because relative timing of appearance of shad and bluegills probably influences their relative success, we quantified densities of fish larvae and zooplankton during spring through summer in three reservoirs across 8 years (1987–1994), and we conducted three hatchery experiments with varying larval appearance times and gizzard shad densities in plastic bags (1 m3). …

Go to article

Overwinter Growth And Survival Of Age-0 Largemouth Bass (Micropterus Salmoides): Revisiting The Role Of Body Size, James E. Garvey, Russell A. Wright, Roy A. Stein Nov 1998

Overwinter Growth And Survival Of Age-0 Largemouth Bass (Micropterus Salmoides): Revisiting The Role Of Body Size, James E. Garvey, Russell A. Wright, Roy A. Stein

Publications

How large size affects overwinter growth and survival of age-0 fish may vary as a function of food, predation, and energetic condition. During two winters in Ohio, we assessed how these factors affected growth and survival of varying sizes of age-0 largemouth bass (Micropterus salmoides) by combining a field survey (N = 2 reservoirs) with multiscale experiments (reservoirs, ponds, outdoor pools). In our survey, more small (< 100 mm total length) individuals died by spring in one reservoir than in the other. Similarly, when we stocked two reservoirs with marked age-0 largemouth bass in fall, mortality of small individuals was higher in one system overwinter, potentially due to differences in predation intensity. In ponds during two winters, size-selective mortality of small largemouth bass occurred in only two of eight ponds, potentially as a function of cannibalism. Varying ration in pools (starved, 0.5× maintenance, or 1.5× maintenance) did not affect survival, even though starved individuals lost substantial wet weight and energy content. Only when predators were present did small individuals die at high rates, although energy depletion may have contributed to predatory mortality. To increase the probability of overwinter survival, managers should seek to improve first-summer growth, reduce winter predation, and increase winter forage.

Go to article

30 Years At Heshbon, Douglas A. Jones Oct 1998

30 Years At Heshbon, Douglas A. Jones

Publications

In 1968, Andrews professor of archaeology Siegfried Horn selected the Jordanian village of Hesban as the site of the university’s archaeological attention. Focus visits Jordan for the 30th anniversary celebration and takes you on location.

Go to article

Wiyn Open Cluster Study. I. Deep Photometry Of Ngc188, Ted Von Hippel, Ata Sarajedini Oct 1998

Wiyn Open Cluster Study. I. Deep Photometry Of Ngc188, Ted Von Hippel, Ata Sarajedini

Publications

We have employed precise and carefully calibrated V - and I - band photometry of NGC 188 at WIYN Observatory to explore the cluster luminosity function (LF) and study the cluster white dwarfs. Our photometry is offset by V = 0.052 (fainter) from that of Sandage and Eggen & Sandage. All published photometry for the past three decades has been based on these two calibrations, which are in error by 0.05 ± 0.01. We employ the Pinsonneault et al. fiducial open cluster main sequence to derive a distance modulus of 11.43 ± 0.08 and E(B - V )=0.09, with …

Go to article

Nuclear Reactions Governing The Nucleosynthesis Of 44ti, L.-S. The, Donald D. Clayton, L Jin, Bradley S. Meyer Sep 1998

Nuclear Reactions Governing The Nucleosynthesis Of 44ti, L.-S. The, Donald D. Clayton, L Jin, Bradley S. Meyer

Publications

Large excesses of 44Ca in certain presolar graphite and silicon carbide grains give strong evidence for 44Ti production in supernovae. Furthermore, recent detection of the 44Ti c line from the Cas A super-nova remnant by the Compton Gamma Ray Observatory Compton Telescope shows that radioactive 44Ti is produced in supernovae. These make the 44Ti abundance an observable diagnostic of supernovae. Through use of a nuclear reaction network, we have systematically varied reaction rates and groups of reaction rates to experimentally identify those that govern 44Ti abundance in core-collapse supernova nucleosynthesis. We survey the nuclear-rate dependence by repeated calculations of the …

Go to article

The Problem Of Hipparcos Distances To Open Clusters. Ii. Constraints From Nearby Field Stars, David R. Soderblom, Jeremy R. King, Robert B. Hanson, Burton F. Jones, Debra Fischer, John R. Stauffer, Marc H. Pisonneault Sep 1998

The Problem Of Hipparcos Distances To Open Clusters. Ii. Constraints From Nearby Field Stars, David R. Soderblom, Jeremy R. King, Robert B. Hanson, Burton F. Jones, Debra Fischer, John R. Stauffer, Marc H. Pisonneault

Publications

This paper examines the discrepancy between distances to nearby open clusters as determined by parallaxes from Hipparcos compared to traditional main-sequence fitting. The biggest difference is seen for the Pleiades, and our hypothesis is that if the Hipparcos distance to the Pleiades is correct, then similar subluminous zero-age main-sequence (ZAMS) stars should exist elsewhere, including in the immediate solar neighborhood. We examine a color-magnitude diagram of very young and nearby solar-type stars and show that none of them lie below the traditional ZAMS, despite the fact that the Hipparcos Pleiades parallax would place its members 0.3 mag below that ZAMS. …

Go to article

The Problem Of Hipparcos Distances To Open Clusters. I. Constraints From Multicolor Main-Sequence Fitting, Marc H. Pinsonneault, John Stauffer, David Soderblom, Jeremy R. King, Robert B. Hanson Sep 1998

The Problem Of Hipparcos Distances To Open Clusters. I. Constraints From Multicolor Main-Sequence Fitting, Marc H. Pinsonneault, John Stauffer, David Soderblom, Jeremy R. King, Robert B. Hanson

Publications

Parallax data from the Hipparcos mission allow the direct distance to open clusters to be compared with the distance inferred from main-sequence (MS) Ðtting. There are surprising differences between the two distance measurements, indicating either the need for changes in the cluster compositions or reddening, underlying problems with the technique of MS Ðtting, or systematic errors in the Hipparcos parallaxes at the 1 mas level. We examine the di†erent possibilities, focusing on MS fitting in both metallicity-sensitive B[V and metallicity-insensitive V [I for five well-studied systems (the Hyades, Pleiades, a Per, Praesepe, and Coma Ber). The Hipparcos distances to the …

Go to article

On The Association Of Gamma-Ray Bursts With Supernovae, Dieter H. Hartmann, R. M. Kippen, M. S. Briggs, J. M. Kommers, C. Kouveliotou, K. Hurley, C. R. Robinson, J. Van Paradijs, T. J. Galama, P. M. Vresswijk Jul 1998

On The Association Of Gamma-Ray Bursts With Supernovae, Dieter H. Hartmann, R. M. Kippen, M. S. Briggs, J. M. Kommers, C. Kouveliotou, K. Hurley, C. R. Robinson, J. Van Paradijs, T. J. Galama, P. M. Vresswijk

Publications

The recent discovery of a supernova (SN 1998bw) seemingly associated with GRB 980425 adds a new twist to the decades-old debate over the origin of gamma-ray bursts. To investigate the possibility that some (or all) bursts are associated with supernovae, we performed a systematic search for temporal/angular correlations using catalogs of BATSE and BATSE/Ulysses burst locations. We find no associations with any of the precise BATSE/Ulysses locations, which allows us to conclude that the fraction of high-fluence gamma-ray bursts from known supernovae is small (<0.2%). For the more numerous weaker bursts, the corresponding limiting fraction of 1.5% is less constraining due to the imprecise locations of these events. This limit (1.5% ≃ 18 bursts) allows that a large fraction of the recent supernovae used as a comparison data set (18 supernovae ≃ 20%) could have associated gamma-ray bursts. Thus, although we find no significant evidence to support a burst/supernova association, the possibility cannot be excluded for weak bursts.

Go to article

African-American Travelers, 1998 July, Author Unknown Jul 1998

African-American Travelers, 1998 July, Author Unknown

Publications

No abstract provided.

Go to article

High Resolution Spectroscopy Of Some Very Active Southern Stars, David R. Soderblom, Jeremy R. King, Todd J. Henry Jul 1998

High Resolution Spectroscopy Of Some Very Active Southern Stars, David R. Soderblom, Jeremy R. King, Todd J. Henry

Publications

We have obtained high-resolution echelle spectra of 18 solar-type stars that an earlier survey showed to have very high levels of Ca II H and K emission. Most of these stars belong to close binary systems, but five remain as probable single stars or well-separated binaries that are younger than the Pleiades on the basis of their lithium abundances and Hα emission. Three of these probable single stars also lie more than 1 mag above the main sequence in a color-magnitude diagram, and appear to have ages of 10 to 15 Myr. Two of them, HD 202917 and HD 222259, …

Go to article

Lithium In The Young Cluster Ngc 2264, Jeremy R. King Jul 1998

Lithium In The Young Cluster Ngc 2264, Jeremy R. King

Publications

We use moderate-resolution, moderate signal-to-noise ratio spectroscopy to derive Li abundances for six F and G stars in the young (few Myr) cluster NGC 2264. These are combined with consistently determined abundances of five NGC 2264 G and K stars having published Li data. The mean non-LTE abundance, calculated with photometric temperatures, is log N(Li) = 3.27 ± 0.05. This is essentially identical to the meteoritic value, providing no evidence of Galactic Li enrichment over the past 4.6 Gyr—at least to the extent that the meteoritic value represents a typical "cosmic" value at that time. The scatter of 0.16 dex …

Go to article

Taking A Pragmatic Behavioral Approach To Alternative Agriculture Research, Leslie Duram Jun 1998

Taking A Pragmatic Behavioral Approach To Alternative Agriculture Research, Leslie Duram

Publications

This article seeks to stimulate thought on the philosophy behind agricultural research. Pragmatism is identified as a philosophical basis for studying environmental issues that focus on human behavior. The ways in which this approach is applicable to the study of alternative agriculture are illuminated. “Behavioral pragmatists” differ from “behavioral positivists” in their aim, focus, process, and approach to research. I describe the main goals of the pragmatic behavioral approach: accepting a systems approach to study the interrelationships between humans and the environment; gaining understanding through human experiences; viewing problems as whole complex “problematic situations”; and promoting social activism and appropriate …

Go to article

Theory Of Quasi-Equilibrium Nucelosynthesis And Applications To Matter Expanding From High Temperature And Density, Bradley S. Meyer, Tracy D. Krishnan, Donald D. Clayton May 1998

Theory Of Quasi-Equilibrium Nucelosynthesis And Applications To Matter Expanding From High Temperature And Density, Bradley S. Meyer, Tracy D. Krishnan, Donald D. Clayton

Publications

Our first purpose is construction of a formal theory of quasi-equilibrium. We define quasi-equilibrium, in its simplest form, as statistical equilibrium in the face of an extra constraint on the nuclear populations. We show that the extra constraint introduces a uniform translation of the chemical potentials for the heavy nuclei and derive the abundances in terms of it. We then generalize this theory to accommodate any number of constraints. For nucleosynthesis, the most important constraint occurs when the total number of heavy nuclei Yh within a system of nuclei differs from the number that would exist in nuclear statistical equilibrium …

Go to article

Hd 98800: A Unique Stellar System Of Post-T Tauri Stars, David Soderblom, Jeremy R. King, Lionell Siess, Keith S. Noll, Diane M. Gilmore, Todd J. Henry, Edmund Nelan, Christopher J. Burrows, Robert A. Brown, M.A.C. Perryman May 1998

Hd 98800: A Unique Stellar System Of Post-T Tauri Stars, David Soderblom, Jeremy R. King, Lionell Siess, Keith S. Noll, Diane M. Gilmore, Todd J. Henry, Edmund Nelan, Christopher J. Burrows, Robert A. Brown, M.A.C. Perryman

Publications

HD 98800 is a system of four stars, and it has a large infrared excess that is thought to be due to a dust disk within the system. In this paper we present new astrometric observations made with Hipparcos, as well as photometry from Hubble Space Telescope WFPC2 images. Combining these observations and reanalyzing previous work allow us to estimate the age and masses of the stars in the system. Uncertainty in these ages and masses results from uncertainty in the temperatures of the stars and any reddening they may have. We find that HD 98800 is most probably about …

Go to article

Tree Seedling Establishment Across A Hydrologic Gradient In A Bottomland And Restoration, William Conner, R K. Kolka, C C. Trettin, E A. Nelson May 1998

Tree Seedling Establishment Across A Hydrologic Gradient In A Bottomland And Restoration, William Conner, R K. Kolka, C C. Trettin, E A. Nelson

Publications

Seedling establishment and survival on the Savannah River Site in South Carolina is being monitored as part of the Pen Branch Bottomland Restoration Project. Bottomland tree species were planted from 1993-1995 across a hydrologic gradient which encompasses the drier upper floodplain corridor, the lower floodplain corridor and the continuously inundated delta. Twelve species were planted in the three areas based on their flood tolerance and the hydrology of the area. Planted areas are separated by unplanted control strips to assess natural regeneration. A seedling survey conducted in 1997 showed that planted areas had significantly greater seedling densities than unplanted control …

Go to article

Equivocal Notions Of Accuracy And Genetic Screening Of The General Population, Kelly C. Smith May 1998

Equivocal Notions Of Accuracy And Genetic Screening Of The General Population, Kelly C. Smith

Publications

The explosive growth in genetic technology will quickly make possible an unprecedented number of tests for genetically based conditions. A necessary condition for the use of such tests without risk of harm to the patient is that they are “accurate”. However, most discussions of test accuracy in the literature have equivocated between two importantly different meanings of the word. In particular, it must be kept in mind that a high analytical accuracy does not imply a high diagnostic accuracy. Questions about the diagnostic accuracy of genetic tests loom large at present given our limited knowledge of the complex etiology of …

Go to article

Relative Survival And Contribution Of Saugers Stocked In The Peoria Pool Of The Illinois River, 1990–1995, Roy C. Heidinger, Ronald C. Brooks May 1998

Relative Survival And Contribution Of Saugers Stocked In The Peoria Pool Of The Illinois River, 1990–1995, Roy C. Heidinger, Ronald C. Brooks

Publications

Numbers of sauger Stizostedion canadense declined in the Peoria Pool of the Illinois River from the 1970s to the 1990s. Stocking was evaluated as a means of supplementing natural reproduction in the pool. Marked fry were stocked in 1991–1994 (20–176/ha), and marked fingerlings were stocked in 1990–1995 (,1–20/ha). In 1990, fingerlings with a mean total length of 44 mm were stocked in June, and 92-mm fingerlings were stocked in September and October. Relative survival was 4.9:1 in favor of the 44-mm fingerlings. During 1991–1994, relative survival averaged 440:1 for stocked fingerlings (39–61 mm) versus fry. From 1990 to 1995, contribution …

Go to article

White Dwarf Cosmochronometry. I. Monte Carlo Simulations Of Proper-Motion ̶ And Magnitude-Limited Samples Using Schmidt’S 1/Vmax Estimator, Matt A. Wood, Terry D. Oswalt Apr 1998

White Dwarf Cosmochronometry. I. Monte Carlo Simulations Of Proper-Motion ̶ And Magnitude-Limited Samples Using Schmidt’S 1/Vmax Estimator, Matt A. Wood, Terry D. Oswalt

Publications

Observationally, white dwarf stars are a remarkably homogeneous class with a minimum observed Teff ~4000 K. Theoretically, the physics that determines their cooling timescales is relatively more straightforward than that which determines main-sequence evolutionary timescales. As a result, the white dwarf luminosity function has for the last decade been used as a probe of the age and star formation rate of the Galactic disk, providing an estimated local disk age of ~10 Gyr with estimated total uncertainties of roughly 20%. A long-standing criticism of the technique is that the reality of the reported downturn in the luminosity function (LF) …

Go to article

Uaa Student Showcase Journal: Recognizing Excellence (1998), N/A N/A Apr 1998

Uaa Student Showcase Journal: Recognizing Excellence (1998), N/A N/A

Publications

No abstract provided.

Go to article

Can State Reform Shape The Culture And Definition Of Professionalism In Schools?, Jane Clark Lindle Apr 1998

Can State Reform Shape The Culture And Definition Of Professionalism In Schools?, Jane Clark Lindle

Publications

When Kentucky established a comprehensive reform of its schools in 1990, it targeted the nature of professional culture, norms, and activities in education. To explain this reform movement, a narrative analysis of research reports targeting various aspects of the 1990 Kentucky Education Reform Act is reported here. The focus is on identified elements of professionalism: a requisite knowledge base, performance of a social service, broad powers of discretion in performance of a job, and collegial controls on admittance and retention in the profession. The research employed a form of narrative analysis and represents the first step in a synthesis of …

Go to article

Are School Boards An Effective Means Of School Governance? A Micropolitical Perspective, Jane Clark Lindle Apr 1998

Are School Boards An Effective Means Of School Governance? A Micropolitical Perspective, Jane Clark Lindle

Publications

Kentucky has witnessed many changes in educational administration. An assessment of those changes, with a focus on school boards, was done. School boards are not efficient bodies and this is not a problem. If efficiency was the top concern, then minimizing time and costs would be dominant and schools would suffer. School boards are not particularly elite or expert forums and but this is preferable since such boards are forums for public interest. Finally, school boards are regarded as democratic, but by no means are they apolitical. Boards are the middle ground between public and private interests; the focus on …

Go to article

How Does A Principal Use Kentucky's High Stakes Assessment To Monitor And Improve Student Learning?, Ora Cobb Jr, Jane Clark Lindle, James S. Rinehart Apr 1998

How Does A Principal Use Kentucky's High Stakes Assessment To Monitor And Improve Student Learning?, Ora Cobb Jr, Jane Clark Lindle, James S. Rinehart

Publications

This paper explores Kentucky's Education Reform Act (KERA) for improving at-risk students' scores to see if the strategies in one middle school improved standardized and state-performance-based assessment results. The study encompasses two purposes: to use a forced-entry regression model to detect which independent variables were predictors of success for "at-risk" students on the Kentucky Instructional Results Information System (KIRIS), and to offer an analytic model for principals to use in examining the impact of specific school reform initiatives and selected intervention strategies. The paper offers a literature review that discusses Effective Schools research, explains the background for KERA and KIRIS, …

Go to article

Emerging Issues With The Predictive Applications Of The Gre In Educational Administration Programs: One Doctoral Program's Experience, Jane Clark Lindle, James S. Rinehart Apr 1998

Emerging Issues With The Predictive Applications Of The Gre In Educational Administration Programs: One Doctoral Program's Experience, Jane Clark Lindle, James S. Rinehart

Publications

Little information exists as to the efficacy of using the Graduate Record Examination (GRE) as a predictor of success for nontraditional students' graduate studies. Since many students in doctoral education programs are nontraditional matriculants, an investigation of the relationship between GRE scores and student success in one such program is discussed. Records of 74 doctoral students enrolled in educational administration since 1992 were obtained to examine the independent variables. A questionnaire was used to collect faculty perceptions of student scholarship (potential) as the dependent variable. The results indicated three significant predictors of student scholarship potential: grade point average, analytic score …

Go to article

Steps Toward Determination Of The Size And Structure Of The Broad-Line Region In Active Galactic Nuclei. Xii. Ground-Based Monitoring Of 3c 390.3, M. Dietrich, Terry D. Oswalt, B. M. Peterson, P. Albrecht, M. Altmann, Et Al. Apr 1998

Steps Toward Determination Of The Size And Structure Of The Broad-Line Region In Active Galactic Nuclei. Xii. Ground-Based Monitoring Of 3c 390.3, M. Dietrich, Terry D. Oswalt, B. M. Peterson, P. Albrecht, M. Altmann, Et Al.

Publications

Results of a ground-based optical monitoring campaign on 3C 390.3 in 1994-1995 are presented. The broadband fluxes (B, V, R, and I), the spectrophotometric optical continuum flux and the Fλ(5177 Å),integrated emission-line fluxes of Hᵪ Hβ, Hᵧ, He I λ5876 and He II λ4686 all show a nearly monotonic increase with episodes of milder short-term variations superposed. The amplitude of the continuum variations increases with decreasing wavelength (4400-9000 Å). The optical continuum variations follow the variations in the ultraviolet and X-ray with time delays, measured from the centroids of the cross-correlation functions, typically around …

Go to article

Contribution Of White Dwarfs To Cluster Masses, Ted Von Hippel Apr 1998

Contribution Of White Dwarfs To Cluster Masses, Ted Von Hippel

Publications

I have undertaken a literature search through 1997 July 31 of white dwarfs (WDs) in open and globular clusters. I have tried to make a careful evaluation in each case of the likelihood that the object is a WD and that it is a cluster member. The results are presented for 13 open clusters and 11 globular clusters. Currently there are 36 single WDs and Ðve WDs in binaries known among the open clusters, and 340 single WDs and 11 WDs in binaries known among the globular clusters. From these data, I have calculated WD mass fractions for four open …

Go to article

Contribution Of White Dwarfs To Cluster Masses, Ted Von Hippel Apr 1998

Contribution Of White Dwarfs To Cluster Masses, Ted Von Hippel

Publications

I have undertaken a literature search through 1997 July 31 of white dwarfs (WDs) in open and globular clusters. I have tried to make a careful evaluation in each case of the likelihood that the object is a WD and that it is a cluster member. The results are presented for 13 open clusters and 11 globular clusters. Currently there are 36 single WDs and Ðve WDs in binaries known among the open clusters, and 340 single WDs and 11 WDs in binaries known among the globular clusters. From these data, I have calculated WD mass fractions for four open …

Go to article

Full-Wave Modeling Of Small-Scale Gravity Waves Using Airborne Lidar And Observations Of The Hawaiian Airglow (Aloha-93) O(¹S) Images And Coincident Na Wind/Temperature Lidar Measurements, Michael P. Hickey Ph.D., Michael J. Taylor, Chester S. Gardner, Christian R. Gibbons Mar 1998

Full-Wave Modeling Of Small-Scale Gravity Waves Using Airborne Lidar And Observations Of The Hawaiian Airglow (Aloha-93) O(¹S) Images And Coincident Na Wind/Temperature Lidar Measurements, Michael P. Hickey Ph.D., Michael J. Taylor, Chester S. Gardner, Christian R. Gibbons

Publications

Measurements were made of mesospheric gravity waves in the OI (5577 Å) nightglow observed from Maui, Hawaii, during the Airborne Lidar and Observations of Hawaiian Airglow (ALOHA-93) campaign. Clear, monochromatic gravity waves were observed on several nights. By using a full-wave model that realistically includes the major physical processes in this region, we have simulated the propagation of four waves through the mesopause region and calculated the O(¹S) nightglow response to the waves. Mean winds derived from Na wind/temperature lidar observations were employed in the computations. Wave amplitudes were calculated based on the requirement that the observed and …

Go to article

First Prev Next Last