Journal of geomagnetism and geoelectricity
Online ISSN : 2185-5765
Print ISSN : 0022-1392
ISSN-L : 0022-1392
Search
Advanced search
OR
Browse
Search
Volume 40, Issue 9
Displaying 1-6 of 6 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • Obituary (A. Cox)
    S. Uyeda
    1988 Volume 40 Issue 9 Pages 1043-1045
    Published: 1988
    Released on J-STAGE: August 11, 2011
    DOIhttps://doi.org/10.5636/jgg.40.1043
    JOURNAL FREE ACCESS
    Download PDF (594K)
  • Estimation of the Wind Component Normal to a Radar Beam
    Peter T. MAY, Susumu KATO, Shoichiro FUKAO, Toshitaka TSUDA, Toru SATO
    1988 Volume 40 Issue 9 Pages 1047-1052
    Published: 1988
    Released on J-STAGE: September 14, 2010
    DOIhttps://doi.org/10.5636/jgg.40.1047
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    A method is presented whereby a crude estimate of the total wind speed with a single Doppler radar observation may be obtained by making use of the spectral width of the returned signal. This method is demonstrated using data from the MU radar of Japan. However, the accuracy of the estimate is severely limited by spectral broadening due to windshear and turbulence within the radar pulse volume. Therefore the practical applications of this method are limited.
    View full abstract
    Download PDF (547K)
  • Solar Cycle Variation of Thermospheric NO
    A Model Sensitivity Study
    A. KUZE, T. OGAWA
    1988 Volume 40 Issue 9 Pages 1053-1065
    Published: 1988
    Released on J-STAGE: September 14, 2010
    DOIhttps://doi.org/10.5636/jgg.40.1053
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The one-dimensional numerical model, which simulates diurnal and solar cycle variations of nitric oxide (NO), is examined on whether it may reproduce the NO profiles observed with rockets at various phases of solar activity. The model result is highly dependent on the adopted rate coefficients of the reactions N(4S)+O2→NO+O and N(2D)+O→N(4S)+O. The laboratory data on these rate coefficients seem to be incompatible with the observed variation in NO profiles. The variation in the thermospheric NO may affect the thermal structure of the thermosphere. A calculation of the thermospheric temperature shows that the observed NO profiles modify the thermopause temperature by -200K at solar maximum, and that they are consistent with the variation of the thermospheric temperature.
    View full abstract
    Download PDF (1126K)
  • Height Distributions of the Night Airglow Emissions in the O2 Herzberg I System and Oxygen Green Line from a Simultaneous Rocket Observation
    Kazuyuki KITA, Naomoto IWAGAMI, Toshihiro OGAWA, Akihiko MIYASHITA, Hi ...
    1988 Volume 40 Issue 9 Pages 1067-1084
    Published: 1988
    Released on J-STAGE: September 14, 2010
    DOIhttps://doi.org/10.5636/jgg.40.1067
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    A simultaneous measurement of the night airglow emissions at three different bands of the O2 Herzberg I system, originating from higher, middle and lower vibrational states of O2(A3Σ+u), along with the green line of atomic oxygen, was carried out with photometers on board a sounding rocket flown from Uchinoura (31°N). The profiles of the volume emission rates at three different bands of the Herzberg I system are found to be identical, suggesting that the vibrational distribution of O2(A3Σ+u) is almost identical at all emission heights, 90-105km. The ratio of the volume emission rates of the Herzberg I system to the green line shows a weak altitude dependence with a maximum at a height of 95km. The excitation and quenching processes of O2(A3Σ+u) and O(1S) are discussed, to suggest that O2(A3Σ+u) is subjected to a large quenching via collisions with atmospheric molecules but that the quenching of O(1S) is small.
    View full abstract
    Download PDF (1530K)
  • Dipole Axially Symmetric, External Field Components in the Analysis of the Geomagnetic Field
    K. KAWASAKI, J. C. CAIN, R. D. PETERS
    1988 Volume 40 Issue 9 Pages 1085-1102
    Published: 1988
    Released on J-STAGE: September 14, 2010
    DOIhttps://doi.org/10.5636/jgg.40.1085
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Ground measurements of the geomagnetic field contain components from external sources and associated currents induced in the Earth. Some of the external sources, namely ring, magnetotail, and boundary (Chapman-Ferraro) currents, produce relatively uniform fields in the vicinity of the Earth, which approximately parallel the dipole axis of the Earth. These fields are, in part, time-varying on a scale of a few minutes to a few days, but as long as the solar wind blows, they must also contain a quasi-steady component with a time scale of a few tens of days to several years. We develop correction equations to take into account the time-varying part of such axially symmetric external fields using the Dst, index. These equations are then applied to the inclination values Im obtained from the Project MAGNET data for the interval 1957-1966. Even after Dst corrections are made on the difference angle Im-Ic, where c denotes the inclination computed from internal terms only, a residual field remains. We believe this residual field to be evidence for the existence of a steady part of the field that cannot be accounted for by A corrections, and we estimate this residual field, assuming that it is axially symmetric. The steady field thus calculated has an equatorial value of about 40nT, which corresponds to the external spherical-harmonic coefficient g0e1 of the same order and positive sign. The positive sign implies the steady component in the vicinity of the Earth is direction southward.
    View full abstract
    Download PDF (1496K)
  • The Geomagnetic Field at 1982 from DE-2 and Other Magnetic Field Data
    R. A. LANGEL, J. R. RIDGWAY, M. SUGIURA, K. MAEZAWA
    1988 Volume 40 Issue 9 Pages 1103-1127
    Published: 1988
    Released on J-STAGE: September 14, 2010
    DOIhttps://doi.org/10.5636/jgg.40.1103
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Data from the DE-2 spacecraft for September 30, 1981 through January 6, 1983 are combined with data from the MAGSAT spacecraft, from magnetic observatories and from magnetic surveys to derive a geomagnetic field model for the period 1979.5 through 1983.5. Called GSFC(11/87), this model is virtually identical to the GSFC(12/83) model at 1980 and may be regarded as an extention of that model in time to 1983.5. Constant and first derivative (i.e., secular variation) internal coefficients are determined through degree and order 13; first degree external coefficients are determined as a function of the Dst index; and the solution includes calculation of fixed biases, or anomalies, for the observatory data. The MAGSAT and DE-2 data provide very good global data distribution at two epochs. The observatory and survey data distribution is not as good but does adequately link the two satellite epochs so that the resulting secular variation model is of high quality, at least to degree 9. Although DE-2 acquired vector data, preliminary modeling showed that its attitude accuracy was not adequate for satisfactory spherical harmonic analysis of the geomagnetic field. However, the scalar magnitude data are of good quality. Plots of the secular variation are given for three components and the field magnitude. The resulting model differs significantly from the IGRF, again demonstrating the need for satellite data in geomagnetic field modeling.
    View full abstract
    Download PDF (1836K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top