Effects of Hysteresis Between Maximum CME Speed Index and Typical Solar Activity Indicators During Cycle 23

• Published in: Solar physics 2012-12, Vol.281 (2), p.839-846
• Main Authors: Özgüç, A., Kilcik, A., Rozelot, J. P.
• Format: Article
• Language: English
• Subjects: Astrophysics and Astroparticles; Atmospheric Sciences; Corona; Physics; Physics and Astronomy; Solar activity; Solar physics; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Sun
• ISSN: 0038-0938; 1573-093X
• DOI: 10.1007/s11207-012-0087-5

Using the smoothed time series of maximum CME speed index for solar cycle 23, it is found that this index, analyzed jointly with six other solar activity indicators, shows a hysteresis phenomenon. The total solar irradiance, coronal index, solar radio flux (10.7 cm), Mg  ii core-to-wing ratio, sunspot area, and Hα flare index follow different paths for the ascending and the descending phases of solar cycle 23, while a saturation effect exists at the maximum phase of the cycle. However, the separations between the paths are not the same for the different solar activity indicators used: the Hα flare index and total solar irradiance depict broad loops, while the Mg  ii core-to-wing ratio and sunspot area depict narrow hysteresis loops. The lag times of these indices with respect to the maximum CME speed index are discussed, confirming that the hysteresis represents a clue in the search for physical processes responsible for changing solar emission.