HR: 11:50h
AN: SH42A-07    [Abstracts]
TI: A Transition to Fast Flows and Its Effects on the Magnetic Fields and Cosmic Rays Observed by Voyager 2 near 70 AU
AU: * Burlaga, L F
EM: leonard.f.burlaga@nasa.gov
AF: NASA Goddard Space Flight Center, Code 692, Greenbelt, MD 20771 United States
AU: Ness, N F
EM: nfness@bxclu.bartol.udel.edu
AF: Bartol Research Institute, University of Delaware, Newark, DE 19716 United States
AU: Wang, C
EM: cw@space.mit.edu
AF: Center for Space Science and Applied Research, Chinese Academy of Sciences P.O. Box 8701, Beijing, 100080 China
AU: Richardson, J
EM: jdr@space.mit.edu
AF: Massachusetts Institute of Technology, Center for Space Research, Boston, MA 02139 United States
AU: McDonald, F
EM: fm27@umail.umd.edu
AF: University of Maryland, Institute for Physical Science and Technology, College Park, MD 20742 United States
AU: Stone, E
EM: ecs@srl.caltech.edu
AF: California Institute of Technology, Downs Lab MS 220-47, Pasadena, CA 91125 United States
AB: A transition from quasi-periodic flows to increasingly fast flows was observed by Voyager 2 (V2) near 70 AU from 2002.8 to 2004.4. The transition was related to the appearance of coronal holes near the solar equatorial plane on Carrington Rotation (CR)1994. Voyager 2 observed several important features (two cycles of quasi-periodic variations in V and B, a shock at 2003.37, a Merged Interaction Region (MIR) with strong magnetic fields in a region with increasing speed, and a shock at 2004.33. A 1-D multi-fluid MHD model (Wang, C., and J. Richardson, J. Geophys. Res., 106(A12) 29,401-29,408, 2001) shows that these features at V2 evolved from the flows observed by ACE at 1 AU. The changes in the cosmic ray intensity (CRI) greater than 70 MeV/n were related to the magnetic field strength at V2. The quasi-periodic variations were related to variations in CRI, but they produced no appreciable net decrease in the CRI. The first shock and the MIR produced a step-like decrease in the CRI at V2 during 2003. The shock observed by V2 at 2004.33 was followed by a MIR and a fast stream. These events were related to a system of transient flows associated with the October - November 2003 events at 1 AU, and they caused a large decrease in the cosmic ray intensity and a large enhancement of 2.5 MeV protons observed by V2.
DE: 2104 Cosmic rays
DE: 2134 Interplanetary magnetic fields
DE: 2164 Solar wind plasma
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting