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Сообщение о землетрясении
Если Вы ощутили землетрясение, пожалуйста, сообщите о нёмELECTRIC AND MAGNETIC FIELD VARIATIONS AT LOW AND EQUATORIAL LATITUDES DURING SC, DP 2, AND Pi 2 EVENTS
- Space Environment Research Center and Department of Earth and Planetary Sciences Kyushu University, 6-10-1 Hakozaki, Higashi-ku Fukuoka, 812-8581, Japan
- National Institute of Information and Communication Technology 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795, Japan
- Department of Mechanic and Electrical Engineering Tokuyama College of Technology, 3538 Kumetakajo Shunan, 745-8585, Japan
- Institute of Cosmophysical Research and Radiowaves Propagation (IKIR) Far Eastern Branch of Russian Academy of Sciences 684034 Kamchatka Region, Elizovskiy District Paratunka, Mirnaya Str. 7, Russia
Relations of ionospheric electric and magnetic fields at low and equatorial latitudes during SC, DP 2 and Pi 2 events were investigated by analyzing the MAGDAS magnetic data and the Doppler data of our FM-CW ionospheric radar. From the analyses, we found that the ionospheric electric fields at lower latitudes during SC events consist of two components: one is the dawn-to-dusk electric field, which penetrates from the polar ionosphere into the day-and night-side equatorial ionospheres, and the other is the globally-westward electric field (δE = −v × B0 ), which may be induced globally in the ionosphere or caused by a globally-earthward movement (v) of the ionospheric plasmas. The H-component of DP 2 magnetic variation in the 10-nT range observed near the magnetic equator in nighttime shows roughly in-phase relation with those in daytime; however, it cannot be explained by the DP 2 dawn-to-dusk electric field observed at middle latitude in nighttime. A new generation mechanism is needed to interpret the globally coherent DP 2 magnetic variation near the magnetic equator. The compressional Pi 2 magnetic pulsation (δB) observed globally near the magnetic equator is found to show the relation of
ω δB = −k × δE to the ionospheric Pi 2 electric field (δE), where ω is the wave frequency, and the wave vector (k) is directed earthward.
Yumoto K., A. Ikeda, M. Shinohara, T. Uozumi, K. Nozaki, S. Watari, K. Kitamura, V. V. Bychkov, and B. M. Shevtsov Electric and Magnetic Field Variations at Low and Equatorial Latitudes During Sc, DP2, and Pi2 Events // Advances in Geosciences. Vol.14: Solar & Terrestrial Science. 2009. P. 197-212.
