Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 46624 ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ Unusual geomagnetic response to the solar wind dynamic pressure pulse during storm-time Unusual geomagnetic response to the solar wind dynamic pressure pulse during storm-time Lukianova Renata Lukianova Renata Geophysical Center RAS, Moscow, Russia ru Geophysical Center RAS, Moscow, Russia ru 16 6 1 6 29 10 2021 https://rjes.ru/en/nauka/article/46624/view

Mid-to-low-latitude ground magnetometers located on the dayside observe an unusual negative bay in the $H$-component as a direct response to the solar wind dynamic pressure (SWPd) pulse occurring during period of steadily intense southward IMF in the course of the magnetic storm main phase. Occurrence of geomagnetic depression maximizes in the postnoon sector. Geosynchronous satellite also observes a decrease of the dayside magnetic field. Simultaneous high-latitude magnetic disturbances are likely indicative of large strengthening of Region~1 field-aligned current (FAC). Observations seem to confirm the theoretical prediction that Chapman-Ferraro dynamics is replaced by Region~1 FAC dynamics when the IMF is strongly southward and SWPd is high.

Mid-to-low-latitude ground magnetometers located on the dayside observe an unusual negative bay in the $H$-component as a direct response to the solar wind dynamic pressure (SWPd) pulse occurring during period of steadily intense southward IMF in the course of the magnetic storm main phase. Occurrence of geomagnetic depression maximizes in the postnoon sector. Geosynchronous satellite also observes a decrease of the dayside magnetic field. Simultaneous high-latitude magnetic disturbances are likely indicative of large strengthening of Region~1 field-aligned current (FAC). Observations seem to confirm the theoretical prediction that Chapman-Ferraro dynamics is replaced by Region~1 FAC dynamics when the IMF is strongly southward and SWPd is high.

 Solar wind magnetic cloud magnetic storm mid-to-low latitude geomagnetic disturbances Solar wind magnetic cloud magnetic storm mid-to-low latitude geomagnetic disturbances

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