The Solar Cycle Dependence of In Situ Properties of Two Types of Interplanetary CMEs during 1999–2020

Abstract

Generally, in situ parameters of interplanetary coronal mass ejections (ICMEs) are analyzed as a whole, or ICMEs are classified by speed or whether they are with and without magnetic clouds. Zhai and colleagues found that ICMEs with and without flares can be extracted only by the average charge states of iron (Q Fe). In the present study, the ICMEs are categorized into two types, flare CMEs (FCs) and nonflare CMEs (NFCs) by the Q Fe. We find that the occurrence rates of FCs and NFCs are both decreased from solar maximum to minimum. The occurrence rates and proportions of FCs are both higher in solar cycle 23 than in solar cycle 24. In contrast, the occurrence rates of NFCs are almost the same during the two solar cycles. The durations of FCs are longer than those of NFCs. The fractions of FCs and NFCs that are associated with magnetic clouds (MCs) or magnetic field direction rotation evidence are 73% and 69%, respectively. The speed, Q Fe, O7+/O6+, helium abundance (A He), and first ionization potential bias are all higher for FCs than for NFCs. The above parameters inside NFCs and solar wind are almost the same. The solar cycle dependence of the parameters inside NFCs is more clear than that inside FCs. The statistical results demonstrate that the material sources of FCs are not completely the same as those of NFCs. Part of the material inside FCs should come from the lower atmosphere where the A He is higher. The statistical results indicate that all CMEs are associated with flux ropes on the Sun.

The Contribution and FIP Bias of Three Types of Materials inside ICMEs Associated with Different Flare Intensities

“…Statistically, the charge states, helium abundance, and first ionization potential (FIP) bias are all higher than those inside the background solar wind (Cane & Richardson 2003;Richardson & Cane 2004;Reinard 2008;Richardson & Cane 2010;Manchester et al 2017;Owens 2018;Song et al 2021;Shi et al 2022). The charge states inside ICMEs associated with flares are higher than those of ICMEs not accompanied by flares (Lepri et al 2001;Lepri & Zurbuchen 2004;Manchester et al 2017;Shi et al 2022). In addition, the statistical results show that the charge states inside ICMEs are positively correlated with flare intensities (Gopalswamy et al 2013;Zhai et al 2022).…”

“…About 10% (40%) of C-class (M-class) flares are associated with CMEs, and more than 80% of X-class flares are accompanied by CMEs (Yashiro et al 2006;Wang & Zhang 2007). The studies on the connection between flares and CMEs are crucial for understanding the nature of the two phenomena (MacQueen & Fisher 1983;Harrison 1986;Zhang et al 2001;Webb & Howard 2012;Shi et al 2022).…”

“…Generally, the fastest and most energetic kinds of CMEs are associated with strong flares (Webb 2002;Gopalswamy et al 2007). Statistically, the interplanetary CMEs (ICMEs) accompanied by flares are faster than those not associated with flares on the Sun (Gosling et al 1976;Sheeley et al 1999;Moon et al 2002;Chen et al 2006;Wood et al 2017;Lamy et al 2019;Shi et al 2022). The reason that ICMEs associated with flares are fast is that the CMEs can be accelerated more by the magnetic reconnection during flares (Maričić et al 2007;Song et al 2015aSong et al , 2018Zhu et al 2020).…”

“…Recently, the origination and generation mechanisms of ICME materials have been analyzed in a series of studies implemented by Fu et al (2020), Zhai et al (2022), andShi et al (2022) in the same group. First, Fu et al (2020) find that the materials heated by the chromospheric evaporation process at flux rope footpoint regions can be injected into CMEs.…”

The Properties of Small Magnetic Flux Ropes inside the Solar Wind Come from Coronal Holes, Active Regions, and Quiet Sun

“…Generally, MCs are associated with stronger magnetic field strengths, lower proton temperatures, and lower plasma beta in comparison with SW (Lepping et al 1990;Burlaga 1991;Cane & Richardson 2003). Statistically, the charge states, first ionization potential (FIP) bias, and helium abundance (A He ) inside MCs are higher than those inside the background SW (Woo et al 2004;Rouillard et al 2010a;Manchester et al 2017;Owens 2018;Song et al 2021;Shi et al 2022). There is a consensus that MCs originate from the Sun and are closely related to the violent eruption events on the Sun.…”