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Waldman, H.

Publications and source records attributed to Waldman, H..

5 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

The specification of distributed boundary conditions in numerical simulation of the ionosphere

The approach described makes it possible to use boundary conditions which do not have to be associated with any particular point of the solution interval. The approach was applied in a program which solves simultaneously the coupled differential equations describing the concentrations of the O(+) ions, their temperature, the electron temperature and the concentrations of O2(+), NO(+) and N2(+) ions. Several versions of the proposed scheme are described for various kinds of boundary conditions. Attention is given to a given columnar ionic content, a given incoming or outgoing flux, or a given height of the peak concentration.

Waldman, H.↗
NASA NTRS1973

Zonal drifts of irregularities imparted by meridional winds.

In a uniform ionosphere, meridional winds cause only meridional motions of irregularities. It is shown, however, that, if F-region irregularities are considered in a real ionosphere in which there is a highly conductive E-layer, zonal motions occur. During the day a substantial westward drift takes place, while at night the drift is eastward but smaller, owing to the much smaller E-layer conductivity. Thus, the effect of meridional winds is to impart a net westward drift to small irregularities in the ionization, provided such irregularities persist long enough.

Waldman, H.↗
NASA NTRS1972

Neutral winds implied by electron content observations during the 7 March 1970 solar eclipse.

Measurements of columnar electron content using geostationary satellite signals were made at several of our observatories throughout the U.S., during the 7 March 1970 solar eclipse. The ionospheric response to the solar eclipse was simulated in a computer. Discrepancies between observed and simulated electron content behaviors can be greatly reduced by assuming the existence of plausible neutral winds originated by the eclipse in the F-region heights.

Almeida, O. G.↗
NASA NTRS1971

The coupling between the ionosphere and the protonosphere and its implications on the long term variations of ionospheric electron content

The long-term variations in the daytime exchange flux are estimated with the use of model hydrogen concentrations based on the inverse relationship between the abundance of neutral hydrogen and the neutral temperature in the thermosphere. The results are found to be compatible with the observed long-term behavior of the ionospheric electron content at a midlatitude location, as revealed by Faraday observations using geostationary satellites. The basic processes occurring in the ionosphere are reviewed, with emphasis on the concepts of limiting velocity and limiting flux. An approach to the problem of numerical simulation of the ionosphere is also presented and discussed.

Waldman, H.↗