Effects of drift on the transport of cosmic rays. IV - Modulation by a wavy interplanetary current sheet

view Abstract Citations (353) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Effects of drift on the transport of cosmic rays. IV - Modulation by a wavy interplanetary current sheet Jokipii, J. R. ; Thomas, B. Abstract The effect of a wavy interplanetary current sheet on the solar modulation of galactic cosmic rays is studied. A simple model of the heliospheric magnetic field is employed in which there is an Archimedean spiral magnetic field directed in one direction above the current sheet and another direction below. The current sheet itself is taken to be the extension by the solar wind of a surface that, at the sun, is a plane inclined at an angle alpha to the solar equator. Two magnetic sectors will therefore be seen by an observer within an angle alpha of the heliographic equator. A simple approximate model is used to investigate modulation. As the tilt angle alpha is increased from zero, it is found that the cosmic-ray intensity decreases. For reasonable variation of alpha from approximately 10 deg to approximately 30 deg, the change in intensity can be compared to that observed as one goes from solar minimum to solar maximum. It is concluded that changes in the waviness of the interplanetary current sheet can have an important, and perhaps dominant, effect in producing solar modulation of galactic cosmic rays. Publication: The Astrophysical Journal Pub Date: February 1981 DOI: 10.1086/158675 Bibcode: 1981ApJ...243.1115J Keywords: Cosmic Rays; Current Sheets; Galactic Radiation; Interplanetary Magnetic Fields; Radiation Transport; Solar Activity Effects; Astronomical Models; Interplanetary Medium; Modulation; Pioneer 10 Space Probe; Solar Cycles; Solar Rotation; Space Radiation full text sources ADS |