The response of the azimuthal component of the ionospheric electric field to auroral arc brightening

• Main Authors: Safargaleev, V., Lyatsky, W., Gazey, N. G., Smith, P. N., Kriviliov, V.
• Other Authors: Polar Geophysical Institute of Russian Academy of Sciences (PGI), Russian Academy of Sciences Moscow (RAS), EISCAT Group, STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), Space Physics Group, University of Sussex
• Format: Article in Journal/Newspaper
• Language: English
• Published: CCSD 2000
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; EISCAT
• Online Access: https://hal.science/hal-00316542; https://hal.science/hal-00316542v1/document; https://hal.science/hal-00316542v1/file/angeo-18-65-2000.pdf

International audience We have analyzed the response of azimuthal component of the ionospheric electric field to auroral arc activity. We have chosen for analysis three intervals of coordinated EISCAT and TV observations on 18 February, 1993. These intervals include three kinds of arc activity: the appearance of a new auroral arc, the gradual brightening of the existing arc and variations of the arc luminosity. The arcs were mostly east-west aligned. In all cases, the enhancement of arc luminosity is accompanied by a decrease in the westward component of the ionospheric electric field. In contrast, an increase of that component seems to be connected with arc fading. The observed response is assumed to have the same nature as the "short circuit" of an external electric field by the conductor. The possible consequence of this phenomenon is discussed. Keywords. Ionosphere (electric fields and currents; ionospheric irregularities) · Magnetospheric physics (auroral phenomena)