巻号一覧
32 巻, 3 号
選択された号の論文の5件中1～5を表示しています
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V. P. PATEL, H. CHANDRA1980 年 32 巻 3 号 p. 129-136
発行日: 1980年
公開日: 2010/03/12
ジャーナル フリーIonospheric E-region drifts at Yamagawa are studied from the published results for the year 1964. The drift pattern is highly seasonally dependent and similar to that reported for tropical latitude stations of Ahmedabad and Udaipur. Small changes due to lunar effects have been noted to occur.抄録全体を表示PDF形式でダウンロード (583K) -
R. P. KANE, V. P. PATEL1980 年 32 巻 3 号 p. 137-144
発行日: 1980年
公開日: 2010/03/12
ジャーナル フリーChoosing quiet days in 1964 wnen counter-electrojets occurred at the equatorial station Trivandrum in India, the H, X and Y variations were examined at northern locations in the same longitude zone. It was noticed that, in summer (May, June, July, August) nothing abnormal happened at the low and middle latitudes. But in winter and equinoxes, strong equatorial counter-electrojets were associated with larger amplitudes of H, X and Y at low and middle latitudes. Thus, equatorial counter-electrojets may be related to intensifications of the winter hemisphere Sq current systems. A preliminary analysis for Huancayo at equator and Fuquene at a low latitude in the American zone did not reveal any similar consistent relationship. This needs furthur investigation.抄録全体を表示PDF形式でダウンロード (758K) -
G. B. ONOLAJA, J. O. OYINLOYE1980 年 32 巻 3 号 p. 145-154
発行日: 1980年
公開日: 2010/03/12
ジャーナル フリーE and F region drift records observed (by the Mitra method) at Ibadan between November, 1974 and March, 1975 have been subjected to both the full correlation and dispersion methods of analyses. The paper examines the relative occurrence frequency of dispersive motions in E and F region records at an equatorial station and the validity of the suggestion by JONES and MAUDE (1972) that inadequate spacing of receiving aerials could be responsible for the low value of the true velocity V of the correlation analysis relative to the mid-frequency range of the Fourier velocities obtained by dispersion analysis. This of course requires the determination of aerial spacing that could be considered adequate for E and F region drift measurements at Ibadan. Finally, as an aid to the interpretation of dispersion analyses results, the degree of the consistency with which both the correlation and dispersion methods of analyses could detect steady winds or bulk motion in E region records has been investigated.抄録全体を表示PDF形式でダウンロード (1003K) -
R. D. RUSSELL, T. WATANABE1980 年 32 巻 3 号 p. 155-170
発行日: 1980年
公開日: 2010/03/12
ジャーナル フリーIt is shown that an induction-type, geomagnetic sensor can be simply calibrated by using it as one arm of a balanced Wheatstone bridge, and by driving the bridge with an oscillator. The theoretical development of the calibration procedure takes into account the possibility that the sensor properties are not linear and therefore the calibration procedure can be used to detect nonlinearities. The theory does not demand that the input signal be sinusoidal.
Certain sensor configurations lead to exact analytical expressions for the calibration parameters. These include the various ellipsoids of revolution, for which special cases give results for the long, slender solenoid and for the flat disc. Expressions are also obtained for air-core cylinders of finite length, but these latter expressions assume that the sensors are linear.
The theory is extended to frequencies comparable with the sensor resonance frequency, and above, for the cases in which the sensor capacity can be represented by a linear, parallel capacitor.
The configuration suggested lends itself readily to feed-back circuits, including those incorporating digital elements.抄録全体を表示PDF形式でダウンロード (1262K) -
Hidefumi TANAKA1980 年 32 巻 3 号 p. 171-179
発行日: 1980年
公開日: 2010/03/12
ジャーナル フリーGeomagnetic paleointensities were determined by making use of the Thellier's double heating method from the recent four lava flows of Sakurajima Volcano, West Japan. Bunmei (1471) and An-ei (1779) lavas were used for inferring the geomagnetic intensities at the respective ages of eruption, and Taisho (1914) and Showa (1946) lavas were used for checking the validity of paleointesity determination by this method. The NRM's of these lavas are highly stable and the paleointensity experiment was successfully applied to all the four lavas. The fact that the intensity determined from Showa lava, i. e. 0.46±0.02Oe, agrees very well with the present-day intensity of geomagnetic field shows that the present measuring device works well. The usual paleointensity experiment was a little modified by making heating and cooling time shorter with the aid of a movable heater. Amounting to 0.42±0.03Oe, the measurement of Taisho lava led to a value a little smaller than the value expected from the actual observation. This could be attributed to the local geomagnetic anomaly on the volcano. As for the historical lava flows, the results indicate that the total intensity of geomagnetic field was 0.53 and 0.48Oe at 1471 and 1779, respectively, and had a tendency to decrease at Sakurajima since the 15th century. This tendency agrees with the geomagnetic secular changes observed at other places in Japan.抄録全体を表示PDF形式でダウンロード (852K)
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