On 15 November 2003, at ∼2030 UT, Ulysses/SWOOPS observed the onset of a large, unusually fast interplanetary coronal mass ejection (ICME) in the solar wind at 5.2 AU. Ulysses measured the peak solar wind flow speed associated with this event, νmax = 993 km s-1, in the turbulent sheath region preceding the ICME. This is the fastest solar wind speed recorded by Ulysses/SWOOPS at this distance since November 1992. On 7 November 2003 at 1554 UT, SOHO/LASCO observed the solar counterpart of this ICME behind the west limb of the Sun; the CME had a plane-of-sky speed of 1995 km s-1. We believe this CME originated in AR 0486, the same active region responsible for the extremely fast ICMEs that impacted the Earth on 29 and 30 October 2003. The ICME took at least 4.3 days to propagate past Ulysses and had a radial width of ∼2.1 AU. The ICME was a magnetic cloud, with a depressed proton beta of ∼0.01 and a smooth rotation of the magnetic field polar angle from 43° to -62°. In addition, Ulysses/SWOOPS also observed bidirectional electron streaming throughout the ICME, indicating that even at this distance, closed field lines threaded the entire event. In the days preceding the ICME, Ulysses observed disturbed solar wind conditions, including six shocks from 6 November to 15 November and several small ICMEs, indicating a high degree of solar activity.
All Science Journal Classification (ASJC) codes
- Space and Planetary Science