摘要:

Simultaneous balloon observations of auroral‐zone electron precipitation from College and Fort Yukon, Alaska, in June of 1962 showed examples of the electron influx increasing with increasing geomagnetic latitudes, both with and without magnetic bay disturbances. Under more disturbed conditions, the X‐ray flux recorded by the southern balloon far exceeded that by the northern balloon, indicating a sharp boundary for the electron precipitation region as suggested by O'Brien on the basis of satellite measureme

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06069

年代:1963

数据来源: WILEY

摘要:

We present a direct method for calculating the variation in magnetospheric electron density with height from a knowledge of the dispersions of whistling atmospherics at different geomagnetic latitudes. The method is applied to published data on the variation of dispersion with latitude during 1957, and the magnetospheric electron densities for this period are derived. The results are comparable to those obtained by other investigators who used different approaches to the problem.

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06079

年代:1963

数据来源: WILEY

摘要:

A theory of the two‐stream ion wave instability in a plasma is developed that takes into account both the effect of collisions of the ions and electrons with neutral particles and the presence of a uniform magnetic field. Applying the results to the ionosphere, we find that irregularities of ionization density should arise spontaneously in regions in which a sufficiently strong current is flowing normal to the magnetic field lines. These irregularities will be strongly aligned with the magnetic field and may have a wide range of wavelengths. The various predictions of the theory are in agreement with the observed characteristics of certain field‐aligned irregularities found in the equatorial ionosphere that are associated with the equatorial electrojet. Similar irregularities often appear in the polar ionosphere during auroral displays; it seems very likely that these are caused by the auroral electro

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06083

年代:1963

数据来源: WILEY

摘要:

Equilibrium solutions for the continuity equation for atomic oxygen ions in the upperFregion in terms of exponential series are developed which take account of diffusion, of the effects of a nondivergent vertical flux of ionization, attenuation of the solar radiation, and lack of temperature equilibrium between the electrons and ions. Above the maximum these series converge rapidly, and they are well approximated by the first few terms. In this way simple solutions of the continuity equation are developed which allow experimentally observed ion‐ or electron‐density profiles to be related to the production, loss, and transport processes. Modified solutions that include the effect of helium and hydrogen ions on the electron‐density profile are developed. The solutions are used to investigate the effects of assuming different neutral atmospheric models on daytime equilibrium profiles. The implications of the solutions to the analysis of experimental profiles are disc

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06099

年代:1963

数据来源: WILEY

摘要:

Plasma resonances, detected in the upper atmosphere with the Alouette topside sounder satellite, have been examined. The resonant frequencies have been found to befNand (fN2+fH2)1/2, wherefNis the plasma frequency andfHis the electron gyrofrequency. The two resonances are attributed to electron oscillations along and across the earth's magnetic field respectively.

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06113

年代:1963

数据来源: WILEY

摘要:

A general analysis of solar radio fluxes between 1000 and 10,000 Mc/s has been made for an entire solar cycle. It is shown that a correlation between a solar radio‐flux index and the temperature of the thermopause can be found in the range of 8–10 cm if its basic component is associated with a 27‐day mean value. A linear correlation is found between the 27‐day mean value of the 8‐cm radio flux and the thermopause temperature. However, there is a departure from linearity at 10.7 cm for fluxes of less than 150 units. The oscillation during a so‐called 27‐day period has a value that is about 50 per cent that of basic component. It is shown that no corpuscular effect is needed in addition to the normal heating of the thermosphere by ultraviolet radiation. A table is given to deduce tha relationships between radio fluxes at 8 and 10 cm and average nighttime and daytime temperatures. Finally, the maximum, mean, and minimum temperatures have been deduced for nighttime and daytime conditions between

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06121

年代:1963

数据来源: WILEY

摘要:

Three sets of rocket data obtained during the period March 1958 through March 1962 have yielded information about the distribution of molecular oxygen in the altitude region 62 to 175 km. The technique employed was that of photographic photometry of absorption spectrums in which an analysis was made of the effects of absorption by atmospheric molecular oxygen on the solar spectrum in the region 1000 to 2000 A in the altitude region of interest. Our results for the altitude region 62 to 85 km are less than, but parallel closely, results obtained from rockets by other investigators and results derived from theoretical considerations. Our data for the critical region 90 to 120 km did not lend themselves to a meaningful analysis. In the region 120 to 175 km our results follow closely results obtained experimentally by Hinteregger, and by Byram, and theoretically by Nicolet, but deviate noticeably from the distribution derived theoretically for this region by Miller.

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06145

年代:1963

数据来源: WILEY

摘要:

Measurements of the 8.4‐ and 10.4‐μ radiation temperature of small regions of Venus were made using an infrared radiometer on Mariner 2. The radiation temperatures agree with broad‐band (8‐ to 13‐μ) earth‐based measurements, the light‐ and dark‐side temperatures are equal, and there is definite limb darkening. The data are consistent with equal radiation temperatures at 8.4 and 10.4 μ, which is interpreted as indicating that the emission is from a cloud structure. No breaks in the clouds were observed. A description of the radiometer instrumentation and

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06157

年代:1963

数据来源: WILEY

摘要:

The extensive and persistent warmth of central and eastern North Pacific waters during the last half of 1962 and early 1963 is described and attributed to prevailing abnormal wind and weather systems. Evidence is presented to indicate that the evolution of the large‐scale prevailing atmospheric systems was partly determined by the anomalous water temperatures as well as forcing influences due to a seasonal change in the elevation of the sun. The evidence is partly statistic‐synoptic and partly physical, involving computations of sensible and turbulent heat exchange as well as radiation balance. Among the more outstanding weather abnormalities treated are the strange behavior of typhoon Freda and the extremely abnormal winter of 1962–1963 over much of the northern hemis

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06171

年代:1963

数据来源: WILEY

摘要:

Seismic models were studied to determine the effect of a sloping interface on the propagation of Rayleigh waves. The two‐dimensional model, 1/16 inch thick, consisted of a plexiglass surface layer and a panelyte half‐space. The surface layer ranged from ¼ to ¾ inch in width with a dip of approximately 2½°. When the variation in layer thickness is linear and gradual, a region of sloping interface (or a wedge‐shaped structure sufficiently remote from its vertex) may be represented to a good approximation by an infinite number of stepped flat layers. The phase velocity of Rayleigh waves determined from a pair of adjacent stations in the region of sloping interface is an ‘effective phase velocity.’ As the distance between the stations approaches zero, the effective phase velocity approaches a limiting value defined as local phase velocity/which is independent of the direction of wave propagation. Outside the region of sloping interface and away from the points of discontinuous slope change, the Rayleigh wave velocities are those appropriate for the flat layer thicknesses; they seem to be unaffected by the nearby sloping interface. As an example, the phase velocities of Rayleigh waves for a generalized crust‐mantle structure with a sloping inte

ISSN:0148-0227    

DOI:10.1029/JZ068i022p06187

年代:1963

数据来源: WILEY