摘要:

Observations with the satellite Explorer 14 to radial distances of 16RE(earth radii) on the generally sunward side of the earth establish the mean geocentric radial distance of the magnetospheric boundary near the sun‐earth line as ∼11REduring May‐August 1963, a period of relatively low geomagnetic activity in the epoch six years after sunspot maximum. Isolated ‘spikes‘ of electrons having 40

ISSN:0148-0227    

DOI:10.1029/JZ069i023p04923

年代:1964

数据来源: WILEY

摘要:

A theoretical solution is given of the boundary shape of a magnetosphere model in which the pressure of the magnetic field inside the boundary is balanced by the pressure of solar wind flow outside the boundary. A constant pressure is assumed present in the wake of the solar wind flow, thus resulting in a model which is closed on the night side of the earth. The solution uses accurate rather than approximate equilibrium conditions, and thus gives an accurate solution of the model situation. The results show the boundary on the night side to be closer to the earth and fatter than has been earlier sketched from qualitative considerations, and the results compare well with the observations of Explorer 10, Explorer 12, and Explorer 14.

ISSN:0148-0227    

DOI:10.1029/JZ069i023p04933

年代:1964

数据来源: WILEY

摘要:

The spatial distributions and time behavior of 40‐ to 110‐Mev trapped protons were observed for approximately nine months on the Injun 3 satellite. Time decay was observed only at the lower edges of the inner belt; extremely stable intensities were observed elsewhere in the regionR<1.5 earth radii. Assuming that an equilibrium proton distribution is established from albedo neutron injection and Coulomb energy loss with the atmosphere, the omnidirectional flux expected from 40 to 110 Mev is calculated for lines of force labeled byL= 1.25 and 1.50. The ratio of the observed unidirectional flux to the calculated value provides a measure of the fraction of neutron decay protons that are trap

ISSN:0148-0227    

DOI:10.1029/JZ069i023p04949

年代:1964

数据来源: WILEY

摘要:

The Vanguard 3 (1959η) scalar magnetic values were compared with values of the geomagnetic intensity as computed using various sets of harmonic coefficients (ten in all). Both the arithmetic mean and the ratio of the rms difference (computed intensity minus observed intensity) to the rms of the observed intensity were computed. The ratio was calculated as a function, sequentially, of the number of harmonic coefficients so as to assess the contribution each coefficient made to the total magnetic intensity. Results are that not only can a ‘best’ set of harmonic coefficients be proffered for describing the geomagnetic intensity at satellite altitudes, but also a minimum number of coefficients, depending on the accuracy desired. Also pinpointed were harmonic coefficients in need of revision, in particular,h21andh31; the maximum contribution to the magnetic intensity by external sources can be estimated to be 10–26

ISSN:0148-0227    

DOI:10.1029/JZ069i023p04959

年代:1964

数据来源: WILEY

摘要:

The concept that comets form tails in the solar wind is reasonably well established, but a suggestion that the moon and the inner planets also cast long shadows in the solar wind has met with objection, mainly on statistical grounds. A lunar or planetary tail would from its nature be difficult to detect, but it is more likely to be found by direct measurement from interplanetary space probes than by complex statistical treatment of existing data.

ISSN:0148-0227    

DOI:10.1029/JZ069i023p04969

年代:1964

数据来源: WILEY

摘要:

Difficulties in testing the statistical significance of lunar effects on the frequency of severe magnetic disturbances are discussed. It is shown that a valid case has not yet been made that the effects are due entirely to chance. The theme that statistical methods should be used as an aid to physical understanding and not as a substitute for it is developed.

ISSN:0148-0227    

DOI:10.1029/JZ069i023p04971

年代:1964

数据来源: WILEY

摘要:

An analysis of 31 years ofKpdata suggests a variation of geomagnetic disturbance with lunar phase. A general increase in geomagnetic activity of about 4% begins after full moon and lasts for seven days. A general decrease in geomagnetic activity of about 4% is found for the seven days preceding full moon. A study of randomized data indicates that the probability that these variations should have occurred by chance is less than 5%. The effect is found to be associated with theKpdata derived from periods of geomagnetic quiet conditions; it is not evident in the data from disturbed periods.

ISSN:0148-0227    

DOI:10.1029/JZ069i023p04975

年代:1964

数据来源: WILEY

摘要:

Certain observations indicate that the auroral electrojets are confined to the auroral arcs. A model of an arc is presented in which the height variation of the auroral ionization is taken into account and vertical currents are allowed to flow. The current flow in the arc is investigated, and the electric field or wind velocity field required to drive the currents is computed for two different cases: in one, the current flow between the auroral‐zone ionosphere and the outer magnetosphere is assumed to be limited and electric fields occur along the magnetic field lines in the magnetosphere; in the other, the conductivity along the field lines is assumed to be perfect. In the first case the electrojets are probably driven by a longitudinal electric field in the magnetosphere. In the second case the driving electric field must be a meridional field in order to explain the observations, and strong sheet currents must flow along the field lines that connect the auroral ionosphere to the outer magnetospher

ISSN:0148-0227    

DOI:10.1029/JZ069i023p04983

年代:1964

数据来源: WILEY

摘要:

Cosmic noise absorption records for a period of more than one year from the South Pole have been analyzed using a standard ‘event report.’ There are two major regions in the diurnal pattern of absorption activity, a magnetic‐night group and magnetic‐day group. The night events tend to be more intense but of shorter duration than the day events, and there is a progressive decrease of intensity during both the day and night groups. These diurnal changes probably correspond to changes in the properties of the energetic particles entering the atmosphere, and these effects are clearly independent of local solar illumination conditions. In a subsequent paper these results will be compared with those from the conjugate station, Frobis

ISSN:0148-0227    

DOI:10.1029/JZ069i023p05001

年代:1964

数据来源: WILEY

摘要:

A new whistler phenomenon has been identified through measurements at ground stations, on an Aerobee rocket between 100 and 200 km, and on the Alouette satellite at 1000 km. The new phenomenon is called the ‘subprotonospheric’ or ‘SP’ whistler, since most of its path appears to be restricted to the region below about 1000 km. The first example of an SP whistler was reported by Barrington and Belrose. In the present report a large number of observations are summarized, and the basic characteristics of the new phenomenon are described. Experimental results are presented which suggest that the whistler ray path is confined to the region between roughly 100‐ and 1000‐km altitude, and that the whistler energy can echo back and forth between these levels. The SP phenomenon occurs mostly at night, typically within a few hours after sunset. SP events are often observed over a period of one or two hours in duration and, for a single Alouette pass, have been observed over a north‐south range as great as 2000 km in extent. The evidence suggests that the SP phenomenon occurs mostly near sunspot minimum and at dipole latitudes greater th

ISSN:0148-0227    

DOI:10.1029/JZ069i023p05009

年代:1964

数据来源: WILEY