摘要:

It is shown that certain plasma instabilities can explain the enhanced and fluctuating magnetic field observed in the layer of disturbed plasma lying between the magnetosphere and the solar wind. Unstable ion waves grow into nonlinear behavior during approximately the foremost one‐fourth of that region. The resulting turbulence, with perhaps some residual oscillation at the frequency of the unstable waves, persists through the rest of the regio

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00369

年代:1964

数据来源: WILEY

摘要:

The data from the neutron detector aboard the Navy research and attitude control satellite 1961 have been processed. A time history of the neutron albedo at ∼1000 km and ∼40°N magnetic latitude covering some 240 days is presented. A time variation of about a factor of 2 occurred in the vicinity of day 95, 1962. A latitude variation is also presented covering the range from 27°N to 45°N magnetic latitude. The final results have been corrected for local neutron production and agree more closely with the results of Hess, Canfield, and Lingenfelter than with the recent results of Lingenfelter. No longitude effect was observed for the neutron albedo, although such an effect is found for the incident cosmic rays. A comprehensive review of all published neutron albedo measurements and comparisons to various theoretical results is presented in the last s

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00377

年代:1964

数据来源: WILEY

摘要:

Freier and Webber have demonstrated that an exponential rigidity spectrum provides a good empirical fit to solar proton data over a wide range of rigidity and during widely different events. In this paper we discuss the conclusions they have drawn about the events of November 12 and 15, 1960, during which a series of rocket flights was made by the Goddard Space Flight Center. We find that for the November 12 event an exponential rigidity spectrum does not fit the observations, owing to the presence of a relatively large number of low‐energy protons, and that data obtained late in the November 15 event are consistent with an exponential rigidity spectrum. We suggest that the difference in character of the spectrums observed in these two events is due to a flux of low‐energy protons arriving at the earth on November 12 with the solar plasma responsible for concurrent geomagnetic disturbances. The flights made late in the November 15 event were during a geomagnetically quiet t

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00393

年代:1964

数据来源: WILEY

摘要:

Studies of the polarizations of the micropulsation phenomenon, pearls, show a number of remarkable effects, in particular, reversals in sense of rotation. In this paper we consider the possibility that the superposition of a succession of signals having rising tones can produce the effects in question. It is shown that, if a number of signals of elliptical polarization all identical except for the inclination of the major axis and frequency are observed simultaneously, various effects, including apparent reversals in sense of rotation, will occur.

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00399

年代:1964

数据来源: WILEY

摘要:

A large number of features can be seen on the ionograms obtained by the Canadian topside sounder satellite. The most useful feature for the calculation of electron density profile is the extraordinary trace; however, to achieve accurate results, the effect of the geomagnetic field must be carefully considered in the data reduction process. The method of analysis we selected assumes that small sections of the profile can be approximated by exponential laminations. This method requires fewer points than other first‐order lamination techniques to achieve a given accuracy. It is usually assumed in the analysis that the received echoes correspond to vertical propagation. This assumption is not always valid, and it can in some cases lead to large errors. The sounder also excites the medium in the immediate vicinity of the satellite, giving rise to various plasma resonances. A graph is given which summarizes the local effects that are seen on the ionograms. This graph can be used for a rapid identification of these resonance

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00407

年代:1964

数据来源: WILEY

摘要:

The solution of a problem recently treated by Goldberg and Schmerling is written in a simple closed form. The problem concerns a possible explanation of the geomagnetic anomaly in terms of diffusion along the magnetic lines of force for a special model of theF2layer at the magnetic equator. At great height the results obtained are roughly in agreement with observations made by the Alouette (S‐27) satellite on October 3, 1962. The theoretical electron density at fixed height is given as a function of magnetic latitude for a wide range of expected conditions at various phases of the solar cycle. Curves showing the latitude variations of [∂(logN)/∂r]−1at great height are also given. The results are di

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00417

年代:1964

数据来源: WILEY

摘要:

The Faraday rotation of 425‐Mc/s radar signals reflected from the moon's surface has been analyzed to yield data on the ionization in the ionosphere. The experimental measurements were taken at Trinidad, West Indies, between January and July 1960. A method is presented which permits resolving the ambiguity of the number of rotations of the plane of polarization when one frequency is employed in radar‐lunar studies. The total integrated electron density in a vertical column through the ionosphere inferred from the radar Faraday data is found to undergo a diurnal variation, having a maximum value during the late afternoon. An analysis of other ionospheric parameters, such as the equivalent slab thickness, the scale height, and the ratio of the electron content above the peak of theFlayer to that below, is also presen

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00429

年代:1964

数据来源: WILEY

摘要:

An approximate analysis is given for VLF propagation in the earth‐ionosphere waveguide of variable height. The height changes are not restricted to points along the great circle path connecting the transmitter and receiver. By choosing a simple example, we show that ionospheric perturbations lying within the first Fresnel zone are most effective in modifying the phase of the received signal. This paper is a sequel to an earlier one published in the Journal in 1961 about ionospheric depressions that were infinite in their transverse dimensio

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00441

年代:1964

数据来源: WILEY

摘要:

A theoretical treatment of the electron displacement in the vicinity of a linear cylindrical antenna immersed in the ionosphere has been developed which explains the surprisingly thick ion sheaths that have been observed experimentally when large RF voltages are applied to the antenna. The force that displaces the electrons is obtained from numerical solutions to the nonlinear differential equation describing their motion, and the results are found to be consistent with the observations.

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00447

年代:1964

数据来源: WILEY

摘要:

From detection of moving ionospheric disturbances by using the backscattering radio sounder technique, Tveten has obtained the velocity distribution of such disturbances. In this paper it is shown that this distribution can be interpreted as the velocity spectrum of neutral acoustic modes propagating in the sound duct at 85‐km altitude. The velocity asymmetry effect observed by Tveten can also be interpreted in terms of the duct model, if it is assumed that the ultimate sources of the disturbances are in the polar region

ISSN:0148-0227    

DOI:10.1029/JZ069i003p00457

年代:1964

数据来源: WILEY