Effect of the solar field reversal on the modulation of galactic cosmic rays

Technical Report · Tue Nov 01 04:00:00 EST 1983

OSTI ID:6575989

Thomas, B T; Goldstein, B E

There is now a growing awareness that solar cycle related changes in the large-scale structure of the interplanetary magnetic field (IMF) may play an important role in the modulation of galactic cosmic rays. To date, attention focussed on two aspects of the magnetic field structure: large scale compression regions produced by fast solar wind streams and solar flares, both of which are known to vary in intensity and number over the solar cycle, and the variable warp of the heliospheric current sheet. It is suggested that another feature of the solar cycle is worthy of consideration: the field reversal itself. If the Sun reverses its polarity by simply overturning the heliospheric current sheet (northern fields migrating southward and vice-versa) then there may well be an effect on cosmic ray intensity. However, such a simple picture of solar reversal seems improbable. Observations of the solar corona suggest the existence of not one but several current sheets in the heliosphere at solar maximum. The results of a simple calculation to demonstrate that the variation in cosmic ray intensities that will result can be as large as is actually observed over the solar cycle are given.

• Research Organization: Jet Propulsion Lab., Pasadena, CA (USA)
• OSTI ID: 6575989
• Report Number(s): N-84-13101
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
COSMIC RADIATION
INTERPLANETARY MAGNETIC FIELDS
IONIZING RADIATIONS
MAGNETIC FIELDS
MODULATION
RADIATIONS
SOLAR ACTIVITY
SOLAR CORONA
SOLAR FLARES
SOLAR WIND
STELLAR ATMOSPHERES
STELLAR CORONAE
VARIATIONS