巻号一覧
41 巻, 3 号
選択された号の論文の4件中1～4を表示しています
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Direction-Finding Analysis of Type III Solar Radio Bursts Observed by the JIKIKEN (Exos-B) SatelliteWataru MIYAKE, Hiroshi OYA1989 年 41 巻 3 号 p. 261-272
発行日: 1989年
公開日: 2010/09/14
ジャーナル フリーThis paper makes a direction-finding analysis of low-frequency type III solar radio bursts observed by the JIKIKEN (Exos-B) satellite and investigates the 2-dimensional distribution and motion of radio sources in interplanetary space. The distribution of radio sources is spread more widely in an east-west direction than in a north-south direction. This is basically attributed to the distribution of active regions on the solar surface, and solar electrons, which are ejected approximately in the radial direction from the sun into interplanetary space. The radial ejection of solar electrons generating type III bursts is also supported by the eastern cutoff phenomena of the longitudinal distribution of optical flares associated with kilometric type III bursts. There is also a correlation between the motion of a radio sources and the associated flare position, though some effects seem to make the correlation less significant.抄録全体を表示PDF形式でダウンロード (988K) -
Reevaluation of the Eddy Diffusion Coefficient and the Role of Water VaporTatsuo SHIMAZAKI1989 年 41 巻 3 号 p. 273-301
発行日: 1989年
公開日: 2010/09/14
ジャーナル フリーThe stability of CO2 in the Martian atmosphere against photodissociation is re-examined. A new one-dimensional model using lower thermospheric temperatures and smaller solar fluxes, which are more appropriate for the time of the Mariner 6/7 experiments, predicts smaller atomic oxygen densities in the upper atmosphere than those predicted by previous investigators. In order to explain the observed O densities in the upper atmosphere (1-2% at 135km), our model requires a vertical eddy diffusion coefficient of -5×107cm2 sec-1, which is much smaller than the previously suggested values (>5×108cm2 sec-1). In the lower atmosphere, catalytic reactions of HOx are essential for reforming CO2 from its dissociation products CO and O. Our results show that the HOx generated by the model using the global average of the observed amount of water vapor (-10μm) catalyzes too much recombination. Diurnal variation in OH densities may help to suppress HOx catalyses, particularly at night. Martian water vapor is highly variable; therefore, the mechanism by which the CO2 level is maintained and its relationship to the water vapor distribution must be considered on a global scale.抄録全体を表示PDF形式でダウンロード (2556K) -
Takashi SHIBATA, Motoaki YASUI, Mitsuo MAEDA, Motowo FUJIWARA1989 年 41 巻 3 号 p. 303-316
発行日: 1989年
公開日: 2010/09/14
ジャーナル フリーGround-based UV DIAL lidar observations of the springtime Antarctic ozone were numerically simulated with realistic ozone and aerosol profiles, using an excimer Raman ozone lidar system whose performance is the same as that at Kyushu University. Computed results show that the ozone profiles can be measured when polar stratospheric clouds (PSC) do not exist. When PSC do exist, the profile may also be observed up to the bottom of the stratosphere. However, in this condition simultaneous co-observation with other observation methods is desirable, since the lidar-observed ozone profile is sensitive to the PSC optical properties.抄録全体を表示PDF形式でダウンロード (1116K) -
H. W. KROEHL1989 年 41 巻 3 号 p. 317-329
発行日: 1989年
公開日: 2010/09/14
ジャーナル フリーThe computation of the total eastward and westward auroral electrojets from numerical modeling techniques for three different intervals during disturbed conditions provides a unique opportunity to evaluate the accuracy of the standard Auroral Electrojet indices AU(12) and AL(12). The effect on the indices of replacing the local magnetic coordinate system with a global system, of increasing the latitudinal coverage by increasing the number of stations from 12 to 57, and of integrating the current density to obtain the total current is considered as new indices are correlated with the standard ones. We conclude that AL(12) is a reasonable measure of the westward electrojet current in a statistical sense, that AU(12) is not as good a measure of the eastward current, and that values of AU(12) and AL(12) during quiet conditions, i.e., less than 50nT, must be treated separately from disturbed conditions. It should also be noted that a rotation of the perturbation vectors into a global coordinate system improves the indices more than an increase in the number of stations.抄録全体を表示PDF形式でダウンロード (1108K)
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