Voyager 2 observations related to the October – November 2003 solar events

[1] A transient flow system observed at 1 AU from October 24–November 7, 2003 (consisting of several shocks, ejecta and possibly other flows) moved away from the Sun for 180 days to 73 AU, where Voyager 2 (V2) observed a large Merged Interaction Region (MIR) associated with a fast (560 km/s) stream that followed a forward shock and moved past V2 for 1.5 solar rotations. The MIR and stream were associated with a large decrease in the cosmic ray intensity and an exceptionally large enhancement in the flux of 2.5 MeV protons. The speed and the cosmic ray profiles observed by V2 were very simple, resembling the profiles of a shock/sheath/ejecta flow and a Forbush decrease, respectively, at 1 AU, but rescaled by a factor by a factor of 10. The onset of the MIR-associated decrease in the cosmic ray intensity occurred 10 days after the shock, lasting several days, with a full recovery 70 days after the onset. Citation: Burlaga, L. F., N. F. Ness, E. C. Stone, F. B. McDonald, and J. D. Richardson (2005), Voyager 2 observations related to the October–November 2003 solar events, Geophys. Res. Lett., 32, L03S05, doi:10.1029/ 2004GL021480.