Effect of the Heliospheric State on CME Evolution

Abstract The culmination of solar cycle 24 by the end 2019 has created opportunity to compare differing properties coronal mass ejections (CMEs) between two whole cycles: 23 (SC 23) and 24). We report on width evolution limb CMEs in SCs order test suggestion Gopalswamy et al. that CME flux ropes attain pressure balance at larger heliocentric distances SC 24. measure as a function distance for significantly large number (?1000) determine where reach constant each cycle. introduced new parameter, transition height ( hc ) CME, defined critical beyond which stabilizes quasi-constant value. Cycle phase-to-phase comparisons are based this parameter. find average value is 62% higher than 23. their peak from Sun do. enhanced observational ratification anomalous expansion. expansion CMEs, caused weak state heliosphere, accounts rope ambient medium attained.