A spatial structure of the plasma micro-turbulence in the solar wind is studied with the interplanetary scintillation method. The diffraction pattern produced by the scintillation represents the projection of the plasma turbulence structure on the observer's plane. Since the method to analyze the structure of the diffraction pattern is generally sensitive to the quality of data, i. e., signal to noise ratio, four different analysis methods are used to derive trustworthy results.
The diffraction pattern has an anisotropic structure, and the direction of its elongation deviates from the radial flow direction systematically in the heliographic coordinate. In the northern hemisphere the elongation deviates counterclockwise from the radial. This situation is reversed in the southern hemisphere, where there is a clockwise deviation from the radial. These evidences imply that the microturbulence is distributed and elongated along the magnetic field.

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RF sounder experiments on board L-3H-9 rocket were carried out in order to investigate the generation mechanism of plasma resonances produced by electrostatic electron cyclotron harmonic (ESCH) waves. The spectrum of the stimulated plasma resonances suggested that there are ESCH waves generated by the instability due to an electron beam, which is caused by antenna charging by an impressed RF field. The observed frequency range of the generated ESCH waves is in agreement with the range theoretically predicted for ESCH wave instabilities triggered by low energy electron beams. The generation of an electron beam is verified by a space simulation chamber experiment. When an RF pulse is applied from a sounder antenna in the chamber plasma, a clear signature of an electron burst was observed. The characteristics of the beam type instability are also verified by K-9M-61 sounding rocket experiment. In the space plasma, beam type instability generates the same branches of the ESCH waves as the plasma resonances by the L-3H-9 plasma sounder experiment.

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This paper will discuss an improved method for determination of vertical ozone distributions from spectral measurements of ultraviolet radiances diffusely reflected from the terrestrial atmosphere. A new inversion method previously presented has been improved, where the effects of multiple scattering and the lower boundary of the atmosphere (ground surface or cloud-top) are incorporated into the inversion procedure. Error bars on the retrieved ozone profiles are also taken into account. The improved inversion algorithm was tested using data of NIMBUS 4 backscattered ultraviolet (BUV) experiments. There is very good agreement between the vertical distributions from observations made from the satellite platform and those made from coincident rocket soundings. The results indicate that the vertical distributions of atmospheric ozone can be obtained by the improved method with high accuracy over a wide range of altitude.
For the future BUV satellite observation, the weighting function has been analyzed from some points of view, then an optimum selection of wavelengths is presented as a result of the weighting function analyses. Furthermore, the use of logarithmically defined parameter of ozone increment is recommended for expanding a dynamic range of the inversion.

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Paleomagnetic data were compiled from the previous studies on volcanic materials in the southern part of Central Japan to investigate the geomagnetic secular variation during the Brunhes epoch. The distribution of compiled 113 VGPs is examined whether or not the Fisher statistics can be applied. Chi-square test indicates that the hypothesis of uniform azimuthal distribution around a mean VGP, which is assumed in the Fisher statistics, is rejected at a 0.05 significance level. Besides, the VGPs tend to concentrate in a certain direction. Azimuthal distributions of the Brunhes epoch VGPs for other regions, France, the Aleutian Islands, the Canary Islands, Comores Island, Crozet Island, Réunion Island and Amsterdam Island, also show similar elongation and azimuthal uniformity can be rejected for these assemblages. Hence the elongation of VGP distribution appears to be a global characteristic in the Brunhes epoch. These elongations can be explained neither by the westward drift of the nondipole fields, by the wobble of the geocentric dipole, nor by the contortion due to transforming field directions into VGPs. Gauss coefficients of the last 200 years geomagnetic field indicate that several nondipole terms changed linearly with the geocentric axial dipole component of g⁰₁. Some of these relationship is possible to have held well not only in the last 200 years but also throughout the Brunhes epoch. In addition, the previous paleointensity studies for the Plio-Pleistocene infer that g⁰₁ changed approximately in a normal distribution. On the basis of these results, a new model for the secular variation is proposed, in which the intensity of dipole term g⁰₁ changes in a normal distribution and those of the correlating nondipole terms vary linearly with a deviation of g⁰₁ from its mean intensity. All combinations of nondipole components are examined and consequently the model with a quadrupole component h¹₂ seems to predict the elongation in azimuthal distribution and the global trend of latitude dependence in angular dispersion. This model appears to have an ability to give a significant and quantitative constraint to the homogeneous dynamo process.

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Spherical harmonic analysis coefficients of the external and internal parts of the quiet-day geomagnetic field variations (Sq) separated for the seven continental regions of the observatories have been used to determine conductivity profiles to depths of about 600km by the Schmucker equivalent substitute conductor method. The profiles give evidence of increases in conductivity between about 150 and 350km depth, then a general increase in conductivity thereafter. For South America we found a high conductivity at shallow depths. The European profile showed a highly conducting layer near 125km. At the greater depths, Europe, Australia and South America had the lowest values of conductivity. North America and east Asia had intermediate values whereas the African and central Asian profiles both showed the conductivities rising rapidly beyond 450km depth. The regional differences indicate that there may be considerable lateral heterogeneity of electrical conductivity in the Earth's upper mantle.

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