摘要:

Electron fluxes, spectrums, and angular distributions have been measured over the energy range of 65 kev to greater than 400 kev on a rocket that was flown along a magnetic field line into the breakup phase of an IBC 1 aurora. Analyses of the data indicate that: (1) the energies and/or pitch angles of all observed electrons, including those with pitch angles of 90°, were probably significantly changed on each bounce owing to nonatmospheric interactions; (2) electron groups with energies above at least 400 kev were observed to be present, to vary independently of lower energy electrons, and to produce differential energy spectrums that were probably double peaked; (3) during quiescent precipitation the angular distribution was independent of energy and was peaked at a pitch angle near 90°. An increase in the precipitating flux was characterized by an increased intensity at all energies and angles, by a softening of the spectrums, and by an angular distribution that became more isotropic with decreasing energy. These features are properties of the electron source or other nonatmospheric process and are not weighted by atmospheric lifetime effects that depend on pitch angl

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04451

年代:1966

数据来源: WILEY

摘要:

Data obtained on a rocket flown into an aurora have shown that a proton‐electron anticorrelation existed in the sense that a decrease (increase) of the lowest energy proton flux at small pitch angles was accompanied within about one second by an increase (decrease) in the corresponding electron flux. Low‐energy protons moving predominately up the magnetic field lines from apparent mirror points well within the atmosphere also show this behavior. The proton‐electron anticorrelation and the predominately upward‐moving protons are interpreted in terms of an electrostatic field oriented along the magnetic fie

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04461

年代:1966

数据来源: WILEY

摘要:

This paper summarizes the properties of the positive‐ion component of the solar wind observed during the four months of the Mariner 2 flight to and past Venus in 1962. The protons' average velocity and temperature were approximately 500 km/sec and 1.7×1050K, respectively. Several streams of hot, high‐velocity plasma were observed to recur at 27‐day intervals, with peak velocity and temperature values of ∼ 830 km/sec and 9×1050K. One of these streams probably existed for at least 18 months. Between streams the velocity dropped as low as 307 km/sec, while the temperature was ∼ 3×1040K. Near 1 AU the average number density was approximately 5 protons/cm3. The density was usually highest at the leading or western edge of each stream, with a maximum value of ∼80 protons/cm3. Otherwise, the density varied inversely with the plasma velocity. The ions' velocity, temperature, and density were calculated from ∼35,000 energy/charge spectrums by fitting the data to isotropic Maxwell‐Boltzmann distributions in a reference frame moving away from the sun at the solar‐wind velocity. A model in which the protons and α particles had equal thermal velocities gives a better fit to the observed spectrums than does an equal‐temperature model. The spectrums usually had high‐energy tails, which became more pronounced at the higher plasma velocities. The velocity, temperature, and high‐energy tail were not strongly dependent on distance from the sun, whereas the density varied approximately as the inve

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04469

年代:1966

数据来源: WILEY

摘要:

The basic theoretical properties of nonsymmetric inflation of a dipole magnetic field by ionized gas are pointed out. It is shown that the distortion ΔBof the field in the neighborhood of the dipole depends very much upon whether there is a nonconducting layer present and upon the configuration of the inflating gas, in contrast to symmetric inflation where ΔBdepends only upon the total energy of the inflating gas. Dissipation of the nonsymmetric portion of the inflating gas is rapid because nonsymmetric inflation drives current down along the magnetic lines of force and across the ionosphere. Dissipation is also rapid because of the nonsymmetric distortion of the field, whose pattern rotates with the azimuthal drift of the inflating gas. The high rate of dissipation implies that nonsymmetric inflation can probably be important only during the active phase of a magnetic stor

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04485

年代:1966

数据来源: WILEY

摘要:

An asymmetric ring current belt consisting of a symmetric ring current and a superimposed partial ring current system is proposed as the explanation for the low‐latitude disturbance daily variation. The magnetic effects of the partial ring current system are derived using a scale model together with a small magnetometer as an analog computer. The magnetic field of an asymmetric ring current belt is derived by assigning an amplitudeAto the partial ring current function and an amplitudeSto the (constant) symmetric ring current function. The span in longitude, the initial position in local time, and the local‐time drift rate of the partial ring current are also adjustable parameters in the asymmetric ring current model. Recovery phases for stations with various longitudes are derived by assuming exponential decays for the partial ring current and symmetric ring current. Measured and computed recovery phases are compared for a few magnetic storms. The comparisons show that even this very simple model of the asymmetric ring current can account for most of the low‐latitude disturbance daily variation in the recovery

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04495

年代:1966

数据来源: WILEY

摘要:

A great magnetic storm commenced on April 17, 1965. Explorer 26 carried a moving magnetic observatory through the inner magnetosphere,L= 2 toL= 6, many times during the development and recovery of the storm. The main phase was asymmetrical and was apparently caused by the rapid growth of a large body of charged particles in the evening and late afternoon quadrants. The recovery phase was more symmetrical and appears to be due to inflation of the magnetosphere by a belt, centered atL= 3.5 on the equator, of charged particles encircling the earth. The decay time constant of this belt was about 4 days.

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04505

年代:1966

数据来源: WILEY

摘要:

The cross sections for charge transfer in collisions between nitric oxide and atomic and molecular positive ions of oxygen and nitrogen have been measured in the energy range from 3 to 200 ev in a crossed‐beam experiment. A smooth interpolation is made between these results and the rate coefficients obtained at thermal energy by the afterglow technique. The dependence of these cross sections upon the energy of the electrons used to produce the primary ions has also been investigated to gain insight into the importance of the states of excitation of the primary ion

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04521

年代:1966

数据来源: WILEY

摘要:

Using the Alouette 1 topside ionograms for equatorial latitudes for the period from September 1964 to February 1965, the diurnal behavior of topside spreadFand its association with magnetic activity has been studied. It is found that there is a negative correlation between the occurrence of topside spreadFandKPindices. From a comparison of spreadFbelowhmF2as observed from the Huancayo bottomside ionograms and the topside spreadFat the same latitude, it is found that, besides the general similarity in their diurnal behavior, the onset of spreadFis earlier in the bottomside compared to that in the topside and that the phenomenon decays later in the topside than in the bottomside. These results are examined in the light of current theories of spreadF, and a qualitative explanation is suggested for the persistence of topside spreadFin the morning hours.

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04527

年代:1966

数据来源: WILEY

摘要:

Project HARP (High Altitude Research Project) is using gun‐launched projectiles to probe the upper atmosphere. Under this program, 130‐mm projectiles have reached 70 km, and 420‐mm projectiles have been placed 143 km over Barbados. The first experimental program for the 420‐mm gun has been the production of luminous TMA trails for the measurement of winds above 90 km. This smoothbore extended gun is 36 meters long, weights 180 metric tons, and has flown vehicles that generate TMA trails from 90 km to 138 km. In the time period July 1964 to February 1966, forty‐nine such nighttime trails have been photographed and twenty‐nine of these analyzed. During twenty‐two of these flights, concurrent ionosonde records have been taken, and the locations of sporadic‐Elayers have been determined for comparison with the wind profiles. The wind data analyzed showed little evidence for the Rosenberg suggestion that the wind vector rotates with increasing altitude. Nine direction reversals occurring in less than 3 km were observed, and fourteen layers of constant direction flow with thicknesses greater than 8 km were observed. A maximum wind speed of 147 m/sec was measured. The six trails of the night of September 20–21, 1965, showed a rapid variation of meridional component of wind at fixed altitude with peak‐to‐peak amplitude of over 200 m/sec. Sine waves were fitted to wind components at fixed altitude with fair‐to

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04535

年代:1966

数据来源: WILEY

摘要:

A two‐frequency radar was operated at Homer, Alaska, to determine the wavelength dependence between 139‐ and 398‐Mhz auroral echoes. The 139‐Mhz radar echoes were, on the average, 22 db greater in amplitude than those received with the 398‐Mhz radar, resulting in a wavelength dependence of λ5. In addition, a trend for the amplitude difference to grow larger as the echoes increased in amplitude was found. Doppler measurements confirm a velocity for the electron irregularities of about 400 km/sec from east to west before magneti

ISSN:0148-0227    

DOI:10.1029/JZ071i019p04545

年代:1966

数据来源: WILEY