HR: 0800h
AN: SH31A-0232    [Abstracts]
TI: GCR Modulation by Small-Scale Features in the Interplanetary Medium
AU: * Jordan, A P
EM: apj2@bu.edu
AF: Boston University, BU Astronomy Dept., 725 Commonwealth Avenue, Room 514, Boston, MA 02215, United States
AU: Spence, H E
EM: hespence@bu.edu
AF: Boston University, BU Astronomy Dept., 725 Commonwealth Avenue, Room 514, Boston, MA 02215, United States
AU: Blake, J B
EM: JBernard.Blake@aero.org
AF: The Aerospace Corporation, P.O. Box 92957, Los Angeles, CA 90009-2957, United States
AU: Mulligan, T L
EM: Tamitha.L.Mulligan@aero.org
AF: The Aerospace Corporation, P.O. Box 92957, Los Angeles, CA 90009-2957, United States
AU: Shaul, D N
EM: diana.shaul@imperial.ac.uk
AF: Imperial College London, Astrophysics Group, Blackett Laboratory, Prince Consort Road, London, SW7 2BZ, United Kingdom
AU: Galametz, M
EM: maud.galametz07@imperial.ac.uk
AF: Imperial College London, Astrophysics Group, Blackett Laboratory, Prince Consort Road, London, SW7 2BZ, United Kingdom
AB: In an effort to uncover the properties of structures in the interplanetary medium (IPM) that modulate galactic cosmic rays (GCR) on short time-scales (from hours to days), we study periods of differing conditions in the IPM. We analyze GCR variations from spacecraft both inside and outside the magnetosphere, using the High Sensitivity Telescope (HIST) on Polar and the Spectrometer for INTEGRAL (SPI). We seek causal correlations between the observed GCR modulations and structures in the solar wind plasma and interplanetary magnetic field, as measured concurrently with ACE and/or Wind. Our analysis spans time-/size-scale variations ranging from classic Forbush decreases (Fds), to substructure embedded within Fds, to much smaller amplitude and shorter duration variations observed during comparatively benign interplanetary conditions. We compare and contrast the conditions leading to the range of different GCR responses to modulating structures in the IPM.
DE: 2104 Cosmic rays
DE: 2134 Interplanetary magnetic fields
DE: 2164 Solar wind plasma
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting