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Unformatted text preview: often cascades of particles caused when the primary particles collide with the atmosphere. If the strength of the galactic cosmic ray influx is measured over a period os measured over a period of time we find that it varies with the solar cycle, only with the opposite phase to solar radiation fluxes like the 10.7 cm flux: This decrease of the cosmic ray flux at solar maximum is known as the "Forbush Decrease" after its discoverer. It is seen to be more marked with altitude. It is believed this is due to the modulation of galactic cosmic rays by the solar wind and Interplanetary Magnetic Field as they diffuse inwards from the heliopause. The stronger the solar wind/IMF, the more the particles diffuse and effectively deflected away from the inner solar system. This effect is so marked that it is thought that cosmic ray detection on the Pioneer spacecraft might have been a better way of detecting the heliopause than direct measurement of the organisation of the solar wind particles....
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This note was uploaded on 12/15/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.
- Fall '10