HR: 09:10h
AN: SH21A-05    [Abstracts]
TI: Why did the January 20 2005 GLE Have Such a Rapid Onset?
AU: Cane, H V
EM: hilary.cane@utas.edu.au
AF: BIRS, 42 Lighthouse Rd, Lunawanna, TAS 7150 Australia
AU: Erickson, W C
EM: bill.erickson@utas.edu.au
AF: BIRS, 42 Lighthouse Rd, Lunawanna, TAS 7150 Australia
AU: * Kaiser, M L
EM: Michael.Kaiser@nasa.gov
AF: NASA/GSFC, Code 695, Greenbelt, MD 20771 United States
AU: Raymond, J C
EM: jraymond@cfa.harvard.edu
AF: Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 United States
AU: Richardson, I G
EM: ianr@lheapop.gsfc.nasa.gov
AF: NASA/GSFC, Code 661, Greenbelt, MD 20771 United States
AU: Duldig, M L
EM: Marc.Duldig@aad.gov.au
AF: Australian Antarctic Division, Channel Highway, Kingston, TAS 7150 Australia
AU: Prestage, N P
EM: nigel@ips.gov.au
AF: Culgoora Solar Observatory, Post Office, Narrabri, NSW 2390 Australia
AB: Three remarkable aspects of the January 20 2005 event are the rapid arrival of the high energy particles, their peak intensity, and the high speed of the associated coronal mass ejection. These characteristics might suggest that a strong shock formed very rapidly and accelerated the energetic particles. However, the associated meter to kilometer wavelength solar radio emissions are unremarkable with no clear early signature of a shock i.e. a metric type II burst. We investigate the proposal that the first arriving particles traversed an extremely quiet interplanetary medium within an interplanetary coronal mass ejection that originated less than 2 days earlier in the same active region as the January 20 event. Such a situation leads to good magnetic connection and minimal scattering.
DE: 2101 Coronal mass ejections (7513)
DE: 2111 Ejecta, driver gases, and magnetic clouds
DE: 2114 Energetic particles (7514)
DE: 2451 Particle acceleration
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005