Antiprotons at solar maximum
When the Sun rotates, it drags its magnetic field with it. The "current sheet," depicted here, is a surface in the solar wind separating regions of opposite magnetic polarity. Solar rotation coupled with solar wind expansion distort the sheet into a wavy spiral shape. The amplitude of the waves increases with solar activity, making it harder for galactic cosmic rays to reach the inner solar system.
General drift directions for protons (positively charged) and antiprotons (negatively charged) when the solar magentic field B has negative polarity, that is, when it points North to South. This field direction is appropriate for the decade 2001 -- 2010. The current solar cycle (since 1990) has the opposite polarity and drift directions. The egg shaped structure represents the heliosphere, that region of the solar system where the solar wind is prominent. The distance between the Sun and the front edge of the heliosphere (left) is 80 to 100 astronomical units (a.u.), while the tail of the heliosphere is more than 300 a.u. away. The red arrows indicate the solar wind speed as a function of solar latitude.
reported by: University of Delaware physicists in Physical Review Letters
