Simple model for the Forbush decrease in galactic cosmic ray flux
We ascribe the classical Forbush decrease (FD) as caused by the transverse flow of particles, which are undergoing essentially two-dimensional diffusion, to the 'sink' provided by the shock front and associated tangential discontinuity produced by a previous solar flare. The appropriate mathematical equations are solved to provide an analytical expression for the time profile of the FD, and by use of a Laplace transform we show that a quasi-equilibrium flow is set up very soon after the appearance of the shock front. The predicted profile is compared with neutron monitor records for individual events as well as with an 'average' event obtained by combining the profiles of 38 individual events. A test of the proposed mechanism is provided by the predicted dependence of the FD on the velocity of the shock front, and the individual events have been chosen so as to illustrate the effect of relatively fast and slow shock velocities. (AIP)
- Research Organization:
- Physics Department, University of Calgary, Calgary, Alberta, Canada
- OSTI ID:
- 7352619
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 81:10
- Country of Publication:
- United States
- Language:
- English
Similar Records
A STUDY OF THE RELATIONSHIP BETWEEN ABSORPTION-TIME PROFILES OF POLAR-CAP- ABSORPTION EVENTS AND FORBUSH DECREASES OF COSMIC-RAY INTENSITY
Did the 28 October 2003 solar flare accelerate protons to (greater-or-similar sign)20 GeV? A study of the subsequent Forbush decrease with the GRAPES-3 tracking muon telescope
Related Subjects
GENERAL PHYSICS
COSMIC RAY FLUX
FORBUSH DECREASE
COSMIC RADIATION
DIFFUSION
INTERPLANETARY MAGNETIC FIELDS
SHOCK WAVES
SOLAR FLARES
SOLAR WIND
IONIZING RADIATIONS
MAGNETIC FIELDS
RADIATION FLUX
RADIATIONS
SOLAR ACTIVITY
640101* - Astrophysics & Cosmology- Cosmic Radiation