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Volume 18 (1966)
- Issue 4 Pages 417-
- Issue 3 Pages 333-
- Issue 2 Pages 109-
- Issue 1 Pages 1-
Volume 18, Issue 4
Displaying 1-10 of 10 articles from this issue
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Satoru MORI1966 Volume 18 Issue 4 Pages 417-430
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSThe 27-day variations of the cosmic ray diurnal variations for 18 consecutive solar rotations of the last solar cycle were studied. During this period, a typical 27-day periodicity in the diurnal variations and the intensity changes of the cosmic rays was observed. With the presence of persistent solar plasma stream, it was found that the phase of the cosmic ray diurnal variations changes periodically.
Comparing the diurnal variations of the meson and the neutron components observed by several stations during these epochs, it is shown that the additional anisotropy producing the periodical changes of the diurnal variations could not be due to an addition of a single anisotropy in the interplanetary space. Assuming two anisotropies having different energy dependences outside the geomagnetic field, the observed changes of the diurnal variations at different places can be consistently explained. Namely, i) The increase of the velocity of plasma stream from the sun can increase the additional flows of cosmic ray particles from the solar directions. ii) The density gradient of cosmic-ray particles across the interplanetary magnetic field lines can produde the diffusion of the particles across the field lines (from 2hr. L. T.). The diffusion coefficient of the cosmic ray particles across the magnetic field lines was estimated to be-1021cm2/sec for the particle of 10GV and was proportional to the particle rigidity.View full abstractDownload PDF (1375K) -
Henry R. RADOSKI1966 Volume 18 Issue 4 Pages 431-436
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSThe wave equation describing the acoustic mode in a plasma magnetized by a dipole field is derived for the case in which the sound speed is much less than the Alfvén speed. The fundamental period of the first order solution is shown to be equivalent to the heuristic concept of a sound wave bouncing back and forth along a field line. This approximate solution is valid at low latitudes. The modification of the acoustic wave equation, when the gravity force is introduced, is discussed.View full abstractDownload PDF (490K) -
B. J. SRIVASTAVA1966 Volume 18 Issue 4 Pages 437-442
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSA study is made of the SSC amplitudes in H in relation to their local time of occurrence in the middle latitudes using data of 10 geomagnetic stations for the period 1953-60. It is found that (1) the greatest SSC amplitudes in H are recorded (in the summer months) around the local midnight (1 to 3 hours before or 1 to 3 hours afterthe local midnight), and (2) the minimum in SSC amplitudes in H occurs (in the winter months) during 18h-21h L. T. at the African stations and during 4h-10h L. T. (generally around 7h L. T.) at the other stations.
The midnight maximum amplitude and the morning minimum amplitude are explained in terms of the ionospheric screening effect and precipitation of electrons into the auroral zone ionosphere on the night side of the earth from the outer Van Allen Belt at the time of the SSC.View full abstractDownload PDF (689K) -
Toshio OGAWA, Yoshikazu TANAKA, Teruo MIURA, Michihiro YASUHARA1966 Volume 18 Issue 4 Pages 443-454
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSA simple observing system for the measurements of vertical electric field component of natural ELF and VLF electromagnetic noises by using ball antennas is described. With this system it is possible to measure long traveled natural ELF noises discriminated from natural local noises due to such as atmospheric electric space-charge fluctuations. Some of the typical recorded noises are shown. Observed ELF noises are divided into three characteristic types; “ELF flash”, “ELF burst” (N-and Q-types), and “ELF continuous”. ELF flashes originate from the lightning discharges in the area within about 1, 000km from the observing station. Occurrences of ELF bursts are more frequent in the daytime than in the nighttime, and are characterized by sudden increase at the time of local sunrise, suggesting the related mechanism of their generation to the solar position relative to the earth. N-type bursts are followed by VLF noises. Source distances of these bursts which are followed by tweek-type atmospherics in the night are estimated to be in the range from 2, 500km to 5, 000km. Q-type bursts often show clear oscillations of the frequencies of Schumann resonances. The daily variations of the mean amplitude of “ELF continuous” which composes the background noises are quite similar to the daily variations of the world thunderstorm activity.View full abstractDownload PDF (1486K) -
A. ONWUMECHILLI, P. O. OGBUEHI1966 Volume 18 Issue 4 Pages 455-461
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDifferent measures of range in use are defined and discussed. Expressions are obtained (a) for correcting the smoothing effects on the various measures of range, and (b) for comparing two measures of range. It is shown how these depend on the time of maximum and therefore to some extent on season. The smoothing corrections when the maximum is at 1100hrs. L. T. vary from 1/2 to 151/2% for measures of range based on averaging over one to 4 hours. The ratio of any two measures of range is found not to be significantly different between H at Huancayo and Z at Ibadan nor between years of solar activity maximum and minimum.View full abstractDownload PDF (631K) -
Nicolai PETERSEN1966 Volume 18 Issue 4 Pages 463-479
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSThe coercive force, Curie temperatur, thermoremanent magnetization and saturation magnetization of tnree basalt samples were measured. The results were supplied by microscopic observations with reflected light and by electron probe microanalyser investigations. One part of each sample was heated in open air, first for 30min, then for 70min and finally for 12h at 700°C, the other part of the same sample was heated in vacuo of 1·10-5Torr at 700°C for 24h. After heat treatment in open air all measused properties show a distinct variation, after heat treatment in vacuo there is scarcely a variation.
The analyses with the microanalyser show a dissolution of the original homogeneous ferrimagnetic mineralcomponent (titanomagnetite) into titanomaghemite and a nonferri-magnetic mineral after heat treatment in open air (the composition of the different components is shown in fig. 6, 7). The transformation of titanomagnetite into titanomaghemite occurs by titaniumemigration.View full abstractDownload PDF (5964K) -
Shigeru MIYAZAKI1966 Volume 18 Issue 4 Pages 481-483
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (210K) -
Masami WADA, Aoi INOUE1966 Volume 18 Issue 4 Pages 485-488
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (370K) -
Peter J. WASILEWSKI1966 Volume 18 Issue 4 Pages 489-491
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (245K) -
Tosio Takeuti, Haruji Ishikawa, Akira Iwata1966 Volume 18 Issue 4 Pages 493-494
Published: 1966
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (138K)
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