- icrc2007@icrc2007.unam.mx
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Contribution Poster (WITHDRAWN)
Speakers
- Mr. C. PEI
Primary authors
- Mr. C. PEI (University of Arizona)
Co-authors
- Prof. J. R. (Randy) JOKIPII (University of Arizona)
- Prof. Joe GIACALONE (Univeristy of Arizona)
Abstract content
From in situ measurements in the heliosphere researchers
have reported the ``reservoir'' phenomenon during the decay
phase of gradual solar energetic particle events. Particle
intensities observed by different spacecraft during individual
gradual events are nearly equal even if the spacecraft are
separated by several AU in radius and latitudinal separations
as large as 70 degrees. M.~A. Lee suggested that adiabatic
cooling is the reason for the reservoir effect. D.~V.
Reames preferred shock acceleration. But the physical
mechanism for this is not yet clear. We demonstrate here
that this phenomenon can be reproduced by a solar-energetic
transport model that includes drift, energy loss, and both
parallel and perpendicular diffusion. We present results of 2D
numerical solution to Parker's transport equation. The
numerical demonstrations of the reservoir phenomenon
are compared with observations from Ulysses , IMP-8,
and ACE during the period of September 12 - 20, 2000.
We find that no special assumptions are necessary to
reproduce the reservoir effect. It is the perpendicular
diffusion that causes the reservoir effect.