Effects of Solar Magnetic Activity on the Charge States of Minor Ions of Solar Wind

Abstract

We present an investigation of the effects of solar magnetic activity on the charge states of minor ions (Fe, Si, Mg, Ne, O, C) in the solar wind using ACE solar wind data, the current sheet source surface (CSSS) model of the corona, and SOHO MDI data during the 23rd solar cycle. We find that the mean charge states indicate a clear trend of increasing with solar activity when the solar wind speed is above 550 km s?1. At lower speeds, no significant solar activity dependence is found. When displayed as a function of solar wind speed, iron is different from other elements in that it displays lower charge states in slow wind than in fast wind. The percentages of the high charge states for species with higher -->m/q (Fe and Si) increase with the solar wind speed, while for the species with lower -->m/q (Mg, O, C), the percentages of the high charge states decrease with the solar wind speed.