Comparative Analysis of Properties of Coronal Mass Ejections at High and Low Apparent Latitudes in 1996–2025

Abstract This study examines the statistical properties of coronal mass ejections (CMEs) over two and a half solar cycles (1996–2025) using coronal observations from the SOHO LASCO CDAW and CACTus catalogs, supplemented by sunspot number records and in situ measurements of interplanetary CMEs (ICMEs) from the Ulysses spacecraft. Focusing on differences between CMEs originating at different apparent latitudes (AL), we analyzed CME annual rates, spatial distributions, and kinematic properties. The total yearly number of CMEs follows the solar cycle, with high-AL CMEs showing a stronger link than low-AL ones. A pronounced solar-cycle-dependent variation is observed between the number of CMEs detected in the corona and the ICMEs in the solar wind. During solar maximum, ICME counts are substantially lower than coronal ejection rates, likely due to enhanced deflection and interaction in the complex interplanetary medium, whereas during solar minimum, Ulysses captured several times more high-latitude ICMEs. ICME occurrence at Ulysses follows the solar cycle with a systematic two-year phase lag. Spatially, high-AL CMEs display a south–north asymmetry, being preferentially directed northward across all phases of the solar cycle except the solar maximum. Low-AL CMEs show a slight southward bias at solar maximum. During the rising phase, they are northward on the western side and southward on the eastern side, with the opposite pattern in the declining phase. The linear speed and angular width of both low- and high-AL CMEs track the solar cycle, with the CME angular width variations preceding sunspot activity, which suggests potential prognostic applications.