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

• Published in: Geophysical research letters Vol. 29; no. 9; pp. 66-1 - 66-4
• Main Authors: Zurbuchen, T. H., Fisk, L. A., Gloeckler, G., von Steiger, R.
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 01-05-2002; Blackwell Publishing Ltd
• Subjects: Charge; Continuums; Coronal loops; Geophysics; Interplanetary Physics; Magnetic fields; Solar activity; Solar activity cycle; Solar cycle variations; Solar cycles; Solar Physics, Astrophysics, and Astronomy; Solar wind; Sources of the solar wind
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2001GL013946

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.