Structure of large amplitude abrupt magnetic variations observed by the MAGSAT
スポンサーリンク
概要
- 論文の詳細を見る
The structure and occurrence characteristics of large amplitude abrupt magnetic variations that are frequently observed over the auroral oval are statistically analyzed using the high time resolution data obtained by the MAGSAT. A superposed epoch analysis shows a systematic difference in the structure between the upward and downward field-aligned currents, confirming that the abrupt variations are due to spatial structure of small-scale field-aligned current sheets. The estimated current density is very high (>90μA/m^2). The high density downward currents are canceled by adjacent strong upward currents, and the net current is upward or almost zero. On the other hand, a high density upward current does not necessarily accompany adjacent strong downward current, and the net current around the region is upward. The thickness of the current sheet is normally 0.5-1.0km or less, suggesting that the events are related to the rayed auroral arc elements. The occurrence frequency decreases rapidly as the amplitude of abrupt jump increases, and the dependence is describable by a simple power function, suggesting that the abrupt jumps are the events that distribute in the high density side trail of the small-scale field-aligned current density distribution.
- 国立極地研究所の論文
著者
-
Nakagawa Akinari
Data Analysis Center For Geomagnetism And Spacemagnetism Faculty Of Science Kyoto University
-
IYEMORI Toshihiko
Data Analysis Center for Geomagnetism and Space Magnetism, Garaduate School of Science, Kyoto Univer
-
Ikeda Tatsuya
Data Analysis Center for Geomagnetism and Spacemagnetism, Faculty of Science, Kyoto University
-
Iyemori Toshihiko
DataAnalysis Center for Geomagnetism and Space Magnetism, Kyoto University
-
Ikeda Tatsuya
Data Analysis Center For Geomagnetism And Spacemagnetism Faculty Of Science Kyoto University
-
Iyemori T
Kyoto Univ. Kyoto Jpn
-
Iyemori Toshihiko
Data Analysis Center For Geomagnetism And Space Magnetism Garaduate School Of Science Kyoto Universi
関連論文
- Local time dependence of the dominant frequency of Pi2 pulsations at mid-and low-latitudes
- Characteristics of CNA associated with geomagnetic sudden commencements
- Geomagnetic sudden commencements observed at the Syowa-Iceland conjugate stations
- Characteristics of polarization of geomagnetic sudden commencements observed at Syowa Station
- Structure of large amplitude abrupt magnetic variations observed by the MAGSAT
- Characteristics of small-scale magnetic fluctuations over the high-latitude ionosphere
- Derivation of polar cap AE indices
- Simultaneous observation of geomagnetic sudden commencement above and below the ionosphere
- Characteristics of solar flare effect in the high-latitude ionosphere as observed by the SuperDARN radars
- Local time dependence of the frequency of Pi2 waves simultaneously observed at 5 low-latitude stations
- Local time features of geomagnetic jerks
- Characteristics of the association between an SC and a substorm onset
- Correlations of AKR index with Kp and Dst indices
- Scale-length dependence of the ratio between the magnetic and electric field perturbations in the ionospheric field-aligned current region
- A statistical study of ULF waves observed by MAGSAT at ionospheric altitude