Multi-point shock and flux rope analysis of multiple ICMEs around 2010 August 1 in the inner heliosphere
Abstract
We present multi-point in situ observations of a complex sequence of coronal mass ejections which may serve as a benchmark event for numerical and empirical space weather prediction models. On 2010 August 1, instruments on various space missions (SDO/SOHO/STEREO) monitored repeated coronal mass ejections originating within tens of degrees from solar disk center. We compare their imprints on four widely separated locations, covering 120 degree in heliospheric longitude, with radial distances from the Sun ranging from MESSENGER (0.38 AU) to Venus Express (VEX, at 0.72 AU) to Wind, ACE and ARTEMIS near Earth and STEREO-B close to 1 AU. Calculating shock and flux rope parameters at each location points to a non-spherical shape of the shock, and shows the global configuration of the interplanetary coronal mass ejections (ICMEs), which have interacted but not merged, making individual identifications still possible. VEX and STEREO-B observed similar magnetic flux ropes, in contrast to the structures at Wind. The geomagnetic storm was moderate to major, reaching two minima in the Dst index, caused by the sheath region behind the shock and one of two observed magnetic flux ropes. MESSENGER received a glancing blow of the ICMEs, and the events missed STEREO-A entirely. The observations demonstrate how sympathetic solar eruptions may immerse at least 1/3 of the heliosphere in the ecliptic with their distinct plasma and magnetic field signatures and emphasize the difficulties in linking the local views derived from single-spacecraft observations to a consistent global picture, pointing to possible alterations from the classical picture of ICMEs.
- Publication:
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Solar Heliospheric and INterplanetary Environment (SHINE 2012)
- Pub Date:
- June 2012
- Bibcode:
- 2012shin.confE..77M