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Skinner, W. R.

Publications and source records attributed to Skinner, W. R..

15 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Observations of the 5-day wave in the mesosphere and lower thermosphere

The 5-day planetary wave has been detected in the winds measured by the High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS) in the mesosphere and lower thermosphere (50-110 km). The appearances of the 5-day wave are transient, with a lifetime of 10-20 days in the two-year data set. The structures of selected 5-day wave events are in generally good agreement with the (1,1) Rossby normal mode for both zonal and meridional components. A climatology of the 5-day wave is presented for an altitude of 95 km and latitudes mainly between 40 deg S and 40 deg N.

Wu, D. L.↗
NASA NTRS1994

Observations of the diurnal tide from space

This study presents a climatology of mesospheric and lower-thermospheric diurnal tidal winds obtained with the High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS). The observations reveal that although tidal structures are present at all times, like the prevailing zonal winds, they exhibit significant semiannual as well as other shorter-term variations in amplitude. Results are presented for a period extending over more than one year from November 1991 to July 1993. The 1,1 diurnal tidal amplitude of the meridional component, characterized by the value at an altitude of 90 km and a latitude of 22 deg, ranges from a minimum at solstice of less than 20 m per sec to an equinox maximum of over 70 m per sec. The vertical wavelength and phase of the tide show only slight variations throughout the year, with a suggestion of semiannual variations in both.

Hays, Paul B.↗
NASA NTRS1994

Observations of the O2 atmospheric band nightglow by the High Resolution Doppler Imager

During nighttime operation the High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS) measures both the horizontal wind field at about 94 km altitude and the limb brightness of the O2(b(sup 1) Sigma(sup +)(sub g) - Chi(cubed)Sigma(sup +)(sub g)) (0,0) atmospheric band airglow. The dominant feature of the observed emission is a latitudinal and local time dependence which is consistent with the (1,1) diurnal tidal mode. A survey of the available data set from November 1991 to July 1993 reveals a semiannual variation in the peak brightness observed at the equator, with maxima observed at the equinoxes and minima at the solstices. These results are consistent with the long-term variations in the diurnal tidal amplitudes detected in HRDI wind measurements.

Burrage, M. D.↗
NASA NTRS1993

Zonal mean winds in the equatorial mesosphere and lower thermosphere observed by the High Resolution Doppler Imager

This paper presents analyses of mesospheric and lower thermospheric zonal mean winds observed by the High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS). Monthly averages of the equatorial zonal mean zonal winds are presented for January 1992 through June 1993. Equatorial zonal winds in the 70-90 km region are dominated by a semiannual oscillation (SAO), ranging from 30 m/s (westerly) to -100 m/s (easterly). At high latitudes the zonal wind variations are predominantly annual. Above 90 km, the low-latitude flow is easterly at all times, punctuated by a small semiannual variation. This behavior may be related to the deposition of momentum by the diurnal tides.

Lieberman, R. S.↗
NASA NTRS1993

Observations of the quasi 2-day wave from the High Resolution Doppler Imager on UARS

A strong westward traveling oscillation, with a period of 2 days and zonal wave number 3, is observed in the mesospheric and lower thermospheric winds from the High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS). The important events happen in January, July, and September/October, of which the occurrence in January is the strongest with an amplitude over 60 m/s. Detailed analyses for the periods of January 1992 and January 1993 reveal a cause-and-effect relationship in the wave developing process at 95 km. The global structures of the wave amplitude and phase are also presented.

Wu, D. L.↗
NASA NTRS1993

Comparison of HRDI wind measurements with radar and rocket observations

Wind fields in the mesosphere and lower thermosphere are obtained with the High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS) by observing the Doppler shifts of emission lines in the O2 Atmospheric band. The validity of the measured winds depends on an accurate knowledge of the positions on the detector of the observed lines in the absence of a wind-induced Doppler shift. These positions have been determined to an accuracy of approximately 5 m/s from the comparison of winds measured by HRDI with those obtained by MF radars. Excellent agreement is found between HRDI measured winds and winds observed with radars and rockets. In addition, the sensitivity of HRDI to migrating tides and other large scale waves is demonstrated.

Burrage, M. D.↗
NASA NTRS1992

Remote sensing of mesospheric winds with the High-Resolution Doppler Imager

Observations of the winds in the upper atmosphere obtained with the High-Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS) are discussed. This instrument is a very stable high-resolution triple-etalon Fabry-Perot interferometer, which is used to observe the slight Doppler shifts of absorption and emission lines in the O2 Atmospheric bands induced by atmospheric motions. Preliminary observations indicate that the winds in the mesosphere and lower thermosphere are a mixture of migrating and non-migrating tides, and planetary-scale waves. The mean meridional winds are dominated by the 1,1 diurnal tide which is easily extracted from the daily zonal means of the satellite observations. The daily mean zonal winds are a mixture of the diurnal tide and a zonal flow which is consistent with theoretical expectations.

Hays, Paul B.↗
NASA NTRS1989

Absorption and emission line shapes in the O2 atmospheric bands - Theoretical model and limb viewing simulations

A multiple scattering radiative transfer model has been developed to carry out a line-by-line calculation of the absorption and emission limb measurements that will be made by the High Resolution Doppler Imager to be flown on the Upper Atmosphere Research Satellite. The multiple scattering model uses the doubling and adding methods to solve the radiative transfer equation, modified to take into account a spherical inhomogeneous atmosphere. Representative absorption and emission line shapes in the O2 1Sigma(+)g - 3Sigma(-)g atmospheric bands (A,B, and gamma) and their variation with altitude are presented. The effects of solar zenith angle, aerosol loading, surface albedo, and cloud height on the line shapes are also discussed.

Abreu, Vincent J.↗
NASA NTRS1986

The dayglow of the O2 atmospheric band system

The dayglow of the O2 atmospheric O2(1Sigma) band system has been simulated by taking into account the three main production mechanisms of the O2(1Sigma) state resonance fluorescence, a photochemical term due to quenching of O(1D), and a pure chemical process. Values of the emission rate, which are involved in the resonant scattering of the O2 atmospheric bands (A, B, and gamma), have been obtained as a function of altitude (0-120 km) and solar zenith angle using a line-by-line calculation. The values of the emission rate, along with updated rate coefficients, have been used in the calculation of the production rate of O2(1Sigma) and the volume emission rate of the (O2 1Sigma, v prime = 0)-(O2 3Sigma, v double prime = 0) transition. The results of these calculations are compared to observational measurements and are found to be in excellent agreement.

Bucholtz, A.↗
NASA NTRS1985

Brightness of the O2 atmospheric bands in the daytime thermosphere

The Fabry-Perot interferometer on Dynamics Explorer 2 was used as a low sensitivity photometer to study the O2 Atmospheric A band during the daytime. A study of the brightness of the emission showed that the assumed source of O2(b1Sigma g +) in the thermosphere, O(1D), can account for the observed intensity up to about 250 km but with a significantly different scale height. This combined with an enhanced brightness above this altitude suggests an additional source for this emission.

Skinner, W. R.↗
NASA NTRS1985

Wind measurements with the High Resolution Doppler Imager (HRDI)

The Upper Atmosphere Research Satellite (UARS), to be launched in 1989, is to provide a global data set required to understand the mechanisms controlling upper atmosphere structure and processes, as well as the response of the upper atmosphere to natural and human perturbations. The High Resolution Doppler Imager (HRDI) is the primary instrument for measuring the dynamics of the stratosphere and mesosphere. The goal of HRDI is to measure wind velocities in the stratosphere and mesosphere during the day and the mesosphere and thermosphere at night with an accuracy of 5 m/sec. HRDI will determine winds by measuring Doppler shifts of atmosphere absorption and emission features. Line of sight winds will be taken in two directions, thus allowing the wind vector to be formed. The HRDI instrument is overviewed. The basis of the measurement is explained, as is an outline of the instrument. Since neither instrument nor observational techniques is fully mature, only a brief sketch is presented.

Skinner, W. R.↗
NASA NTRS1983

Optical effects of spacecraft-environment interaction Spectrometric observations by the DE-B satellite

Data from the Fabry-Perot interferometer on board the Dynamics Explorer-B satellite is used to show that the contaminant glow observed by Yee and Abreu at 7320A on the AE satellites is produced by emission lines of one or more species. A comparison is made of the contaminant spectrum near 7320A with the nightglow OH spectrum measured below 155km. Evidence is presented to the effect that OH might be one of the metastable species producing the glow.

Abreu, V. J.↗