摘要:

When the collision frequency in an ionized gas is smaller than the wave frequency, it is not permissible to treat the gas as a continuous fluid. The equations for Alfvén waves are obtained by working with distribution functions. The results illustrate the behavior of a gas when the collision frequency is low and may have applications in the interstellar gas or in the earth's outer atmosphere

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00323

年代:1954

数据来源: WILEY

摘要:

At College (Fairbanks), Alaska, simple magnetic disturbances of negative bay type are closely related to a sequence of change in the type of auroral activity. General features of the relationship indicate that auroral forms are not independent of the electromotive force responsible for the intense auroral‐zone currents. Following the major −ΔHdisturbance, a short interval of +ΔHdisturbance is observed; this cannot be explained by the existing idealized current‐systems for the auror

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00329

年代:1954

数据来源: WILEY

摘要:

The index of refraction above 20,000 feet is considered, based on measurements by Essen and Froome, and Barrett, for a wide range of radio frequencies. To an accuracy of one part in a hundred thousand, the density of air alone is of importance, and to an altitude of only 26 km. Effects from water vapor, and electron concentrations in the ionosphere for frequencies of 5,000 Mc/sec, were found negligible to the accuracy indicated.

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00339

年代:1954

数据来源: WILEY

摘要:

A technique for simultaneously recording the polarization and virtual height of sweep frequency ionospheric echoes is described. The representative polar and phase diagrams of each echo are recorded on photographic film, with displacement in one direction proportional to virtual height and in the other direction proportional to frequency. Several sample records are shown, together with a block diagram of the equipment.

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00345

年代:1954

数据来源: WILEY

摘要:

During the period 29 May to 23 October 1952, 90 sets of measurements were acquired using the searchlight probing technique. Treatment of the data yielded density, temperature, and pressure information to 67.6 km. These results are discussed relative to seasonal trends. An over‐all average for the period is submitted for the three parameters.The temperature profile obtained for pre‐dawn, 22 October 1952, is compared with rocket, anomalous sound, and radiosonde temperature measurements, all carried out within a 14‐hour period and a 300‐mile radius. Good agreement is evident among the four

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00351

年代:1954

数据来源: WILEY

摘要:

A method employing two helical‐beam antennas is described for measuring polarization effect of radio echoes from non‐shower meteors of unknown trail orientation. Results obtained by the method are in good agreement with theoretical values and with measurements made on shower meteors by another method by Clegg and Cl

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00359

年代:1954

数据来源: WILEY

摘要:

The various methods for determination of ozone distribution are discussed, among them that of utilizing lunar eclipse. With the latter method and under suitable conditions, ozone distribution can be obtained at latitudes where otherwise observations would be difficult to make. Results for different latitudes and altitudes are given.

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00365

年代:1954

数据来源: WILEY

摘要:

The problem of whether the earth's magnetic momentMis increasing or still decreasing cannot at present be definitely answered from a critical review of recent literature. From an investigation of Vestine's successive analyses of the geomagnetic secular variation since around 1910, the conclusion is reached thatM, after having passed through a minimum a few years ago (probably between 1945 and 1952), is beginning to recover at present. A semi‐quantitative explanation of the secular change ofMis afforded on the basis of a physical model of the main geomagnetic field (conception of two eccentric dipoles) as developed in an earlier publication. The hypothesis is advanced of quasi‐periodic cycles of about three centuries, with alternating demagnetization and induction (remagnetization) processes in the earth giving rise to corresponding cycles of decrease and increase

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00369

年代:1954

数据来源: WILEY

摘要:

A CW radio propagation experiment was conducted in the ionosphere with the Viking 5 rocket, launched at 10:18 hours MST on November 21, 1950, at the White Sands Proving Ground, New Mexico. Ordinary and extraordinary indices of refraction at 4.274 Mc were measured in the region surrounding the rocket. From these basic data, it was possible to determine the electron density continuously from 95 to 165 km and to show that the Lorentz polarization term should not be used at 4 Mc. In addition, the rapid decay to extinction of the extraordinary ray between 136 and 142 km was used to compute a value of 0.488 oersted for the earth's magnetic field at 139 km and to set an upper limit of 104per second for the electron collision frequency at 139 km.The results of the Viking flight and also those of previous flights indicate a rapid increase in electron density beginning at 92 km and ending near 110 km. Between 110 and 165 km, the Viking data show that the electron density increased very slowly from 1.3×105el/cc to 1.8× 05el/cc. This distribution and similar evidence previously obtained suggest that during the daytime theE‐layer probably remains dense up to theF‐l

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00377

年代:1954

数据来源: WILEY

摘要:

The problem of recombination of electrons and ions in the lower ionosphere is studied both experimentally and theoretically. The experimental study involving, among others, the measurements on phase height, polarization, and absorption at 150 kc/sec, allows formulation of a tentative distribution of ionospheric recombination coefficient over the range of 60 to 110 km. On the basis of this model, the theories of recombination in the lower ionosphere are examined in detail.The problem of recombination during sudden ionospheric disturbances is also studied.

ISSN:0148-0227    

DOI:10.1029/JZ059i003p00391

年代:1954

数据来源: WILEY