The solar wind composition throughout the solar cycle: A continuum of dynamic states

Abstract

Variations in the speed and elemental and ionic charge composition of the solar wind are reported throughout the solar cycle, as observed by the SWICS instrument on Ulysses. The apparent bimodal nature of the solar wind during the solar minimum does not persist throughout the solar cycle. Rather, with increasing solar activity, a continuum of solar wind speeds and charge states is observed. The exception is the elemental composition which is noticeably less enhanced in elements with low first ionization potential (FIP) in material from coronal holes throughout the solar cycle. These observations are consistent with theories in which the solar wind originates from coronal loops that reconnect with open magnetic field lines.