SAR arc observation as the mapping of plasmasphere dusk-bulge during a magnetic storm
Abstract
The stable auroral red (SAR) arcs are the consequence of interaction of the outer plasmasphere (plasmapause) with energetic ions of the ring current. In this work we analyze the observation of aurorae and SAR arc with the all-sky imager (ASI) at the Yakutsk meridian (130ºE; 200ºE, geom.) during the magnetic storm main phase on March 17, 2015. ASI registers the SAR arc with a maximum of its intensity and the latitude on the westward horizon of station from the start of observations at ~1116 UT during the decrease of magnetic activity after the main phase onset of magnetic storm at ~0630 UT. The measurements of the thermal ion fluxes with ECT HOPE Instrument aboard the Van Allen Probes B satellite at ~1230 UT testify to a plasmapause location on L ~ 3.5 at the meridian ~1825 MLT. The inner boundary of the energetic H+ and O+ ions flux has been registered by the satellite on L ~ 2.8-3.3 at the meridian ~ 1800 MLT at 1210-1220 UT. At this time ASI observes SAR arc up to a meridian 1840 MLT on the westward horizon of station. Further the dynamics of aurorae in the 557.7, 630.0, 470.9 and 486.1 (Hβ) nm emissions owing to sharp changes in the solar wind and during three substorms is observed. We consider differences in the precipitation dynamics of energetic protons and electrons during substorms. It is shown that the SAR arc registered with ASI maps the ring current overlap with the region of plasmasphere dusk-bulge or plume. The research is supported by RFBR grant No 15-05-02372 a.
- Publication:
-
41st COSPAR Scientific Assembly
- Pub Date:
- July 2016
- Bibcode:
- 2016cosp...41E.856I