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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Polarized radiation transfer through inhomogeneous semiinfinite atmosphere by matrix perturbation method, giving nonlinear singular integral equation
Atmospheric density variations and functional dependence of aerodynamic moment coefficient on incident angle from Saturn Workshop flight experiment
Electromagnetic wave transmission in earth atmosphere from 3 kHz to 3000 THz with emphasis on earth to space paths up to Jan. 1970
Scintillation and signal to noise ratio of heterodyne detection for carbon dioxide laser beam propagated over path 3.2 km to determine effects of atmospheric turbulence
Space capsule reentry into Martian atmosphere for soft landing, using onboard nonlinear filter and stochastic control for random wind gusts
Conference papers dealing with remote probe techniques for observing and measuring physical composition and dynamical structure of atmosphere
Atmospheric tides travelling from the mesosphere into the upper thermosphere are discussed. As a preliminary, an elementary discussion of internal gravity waves is presented. Tides excited by the absorption of extreme ultraviolet radiation within the thermosphere are described also. Theory suggests a much larger semidiurnal oscillation in the thermosphere than is observed.
The charged particle observations proposed for the new low altitude weather satellites, TIROS-N, are described that will provide the capability of routine monitoring of the instantaneous total energy deposition into the upper atmosphere by the precipitation of charged particles from higher altitudes. Estimates are given to assess the potential importance of this type of energy deposition. Discussion and examples are presented illustrating the importance in distinguishing between solar and geomagnetic activity as possible causative sources.
Although there have been several theoretical studies and predictions of the Venus atmospheric effects on the radio-frequency wave propagation, the limited experimental data of Venera 4, 5, 6 and 7 do not provide a consistent answer on how severe the turbulence effects could be especially near the Venus surface. In this paper the status of this problem is examined. Important theoretical results are presented. Some meaningful conclusions are drawn from the available experimental data as well as the theoretical analysis.
The middle atmosphere (MA), which is defined as the region bounded below by the tropopause near 10 km and above by the mesopause near 90 to 100 km, is regarded as a passive medium through which electric fields and currents are transmitted from sources above and below. A scientific background is given for: sources of MA electric fields; MA conductivity and currents; and MA plasma characteristics. Recommendations are given for research in MA electrodynamics in the following areas: (1) MA electrodynamical parameters; (2) models and supportive laboratory measurements; and (3) investigation of specific problems in the coupled systems.
A description is presented of the first observations of neutral gravity waves in which a sufficient number of wave parameters are detected to allow a specification of the neutral wave characteristics. In situ measurements of neutral wind, temperature, and composition from Atmospheric Explorer are used to obtain wave amplitudes and phases for N2 temperature and wind, and N2, O, and He densities. These amplitudes and phases along with the Doppler shifted wave frequency provide sufficient information to evaluate the wave frequency and the wave vector.
Gross distinctive radial sequences of stellar atmospheric regions are identified and characterized observationally and thermodynamically. Sequences which include quasi-thermal photospheres, ejected shell photospheres, and spherically pulsating photospheres are discussed.
Intercomparison of middle atmosphere meteorological data from a variety of sources is discussed. The primary aim was to intercompare data on stratospheric and mesospheric temperatures from a variety of sounding systems in order to characterize the differences, to understand the reasons for them, and to help users of the data to understand how these differences will affect derived quantities such as heat and momentum fluxes which are significant in studies of stratospheric dynamics.
A perturbation model to the Marshall Space Flight Center (MSFC) Global Reference Atmosphere Model (GRAM) was developed for use in the Aeroassist Orbital Transfer Vehicle (AOTV) trajectory and analysis. The model reflects NASA Space Shuttle experience over the first twelve entry flights. The GRAM was selected over the Air Force 1978 Reference Model because of its more general formulation and wider use throughout NASA. The add-on model, a simple scaling with altitude to reflect density structure encountered by the Shuttle Orbiter was selected principally to simplify implementation. Perturbations, by season, can be utilized to minimize the number of required simulations, however, exact Shuttle flight history can be exercised using the same model if desired. Such a perturbation model, though not meteorologically motivated, enables inclusion of High Resolution Accelerometer Package (HiRAP) results in the thermosphere. Provision is made to incorporate differing perturbations during the AOTV entry and exit phases of the aero-asist maneuver to account for trajectory displacement (geographic) along the ground track.
The transient response of the climate to increasing CO2 is studied using a modified version of the multilayer energy balance model of Peng et al. (1982). The main characteristics of the model are described. Latitudinal and seasonal distributions of planetary albedo, latitude-time distributions of zonal mean temperatures, and latitudinal distributions of evaporation, water vapor transport, and snow cover generated from the model and derived from actual observations are analyzed and compared. It is observed that in response to an atmospheric doubling of CO2, the model reaches within 1/e of the equilibrium response of global mean surface temperature in 9-35 years for the probable range of vertical heat diffusivity in the ocean. For CO2 increases projected by the National Research Council (1983), the model's transient response in annually and globally averaged surface temperatures is 60-75 percent of the corresponding equilibrium response, and the disequilibrium increases with increasing heat diffusivity of the ocean.
Photometric measurements of the 5577 A O(1S) green line mesospheric emission obtained by the Visible Airglow Experiment on board the Atmosphere Explorer satellite have been analyzed. The inverted volume emission rate profiles showed a peak at approximately 96-97 km with a half-width of about 8 km. The diurnal variation of the intensity indicates the presence of a wave component with a 10 to about 12 h period, probably of solar semidiurnal tide. Shorter time scale variations due to the presence of traveling waves were also observed.
The dependence of the intensity in the sodium D1 and D2 lines on the planetary phase and position of the disk is presented. Theoretical intensities are convolved with an atmospheric point spread function with FWHM of 0.5 and 2.0 arcsec for planetary phases 60 and 90 deg. It is shown that although the absolute intensities are extremely dependent on seeing, the I(D2)/I(D1) ratio remains a reliable indicator of column abundance regardless of the seeing function. For a uniform distribution of sodium, limb brightening will be apparent for a seeing disk with FWHM of 0.5 arcsec but will not be apparent for a FWHM of 2.0 arcsec.
The turbulent diffusion coefficient was computed from the parameters of sporadic E layers using the wind shear theory of midlatitude sporadic E and models of the ionosphere as well as that of the neutral upper atmosphere. The turbulent diffusion coefficient obtained for the period of circulation disturbances associated with stratospheric warmings and for the intervals of the winter anomaly indicate changes similar to the ionospheric absorption of radio waves, in the former case decreased, in the latter case increased values. This may hit at the role of turbulent transport in the formation of these anomalies. On the basis of these findings, a seasonal variation of the turbulent diffusion coefficient having a minimum in summer and an increase of this parameter with increasing geomagnetic activity are anticipated.