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Beer, T.

Publications and source records attributed to Beer, T..

5 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Spatial resonance in the ionosphere.

When the phase velocity of an internal gravity wave equals the natural drift of an ionization irregularity, then a spatial resonance results. If the ionization irregularity has been produced by the gravity wave then it is possible to obtain simple quantitative relations to describe this effect. They indicate this spatial resonance will only occur when the horizontal electric field is westward (i.e., at night), and for tropospherically launched waves it will only affect the ionization at the valley of the equatorial electron density profile.

Beer, T.↗
NASA NTRS1972

Atmospheric wave-induced instability in the nighttime E-region.

Examination of the perturbed continuity equation when the perturbations are the result of an internal atmospheric gravity wave in the E region. The transient response of the ionization is interpreted as the gradient instability and the values of the vertical and horizontal wave numbers that will induce it are plotted for various heights. Only in the presence of westward directed electric fields, which are believed to occur only at night, will the gravity waves induce the gradient instability. Approximate analytic expressions are obtained for the permitted wave numbers as well as for the instability growth times. In the course of this analysis it is shown that in the D region all irregularities, even those that are field-aligned, will tend to move with the ion velocity.

Beer, T.↗
NASA NTRS1972

Nighttime sporadic-E.

At night, internal atmospheric gravity waves are able to induce drift instabilities in the ionospheric plasma. Nighttime constant height type sporadic-E(Esc) may then be explained as an effect due to the combined effect of ionization movement due to the wind shear mechanism and due to the cross-field gradient drifts. This combined concept provides a qualitative explanation of the rocket observed nighttime electron density profiles, of the speeds of the Esc irregularities and of the variations of Esc with latitude and electric field strength.-

Beer, T.↗
NASA NTRS1972

Atmospheric waves and the ionosphere.

A review of evidence supporting the existence of atmospheric waves is presented, and a simple, theoretical approach for describing them is shown. Suggestions for gravity wave sources include equatorial and auroral electrojet, auroral and polar substorm heating, atmospheric jet streams, and large oceanic tides. There are reviewed previous studies dealing with the interaction between ionization and atmospheric waves believed to exist at ionospheric heights. These waves include acoustic waves, evanescent waves, and internal atmospheric gravity waves. It is explained that mode analysis, often employed when an increased number of layers is used for a more complete profile, is inapplicable for waves very close to a source.

Beer, T.↗