The Temporal and Spatial Behaviors of CME Occurrence Rate at Different Latitudes

TL;DR

This study analyzes the temporal and spatial behaviors of CME occurrence rates at different latitudes, revealing correlations with solar activity indices and differences across solar cycles, which enhances understanding of solar-terrestrial interactions.

Contribution

It provides new insights into the latitudinal and height-dependent behaviors of CMEs and their relationship with solar activity indicators across different solar cycles.

Findings

High-latitude CMEs correlate more strongly with CBI than low-latitude CMEs.

Correlation between CMEs and solar activity indices varies between Solar Cycles 23 and 24.

Temporal offsets between indicators suggest variations in CME source regions and magnetic energy processes.

Abstract

The statistical study of the Coronal Mass Ejections (CMEs) is a hot topic in solar physics. To further reveal the temporal and spatial behaviors of the CMEs at different latitudes and heights, we analyzed the correlation and phase relationships between the occurrence rate of CMEs, the Coronal Brightness Index (CBI), and the 10.7-cm solar radio flux (F10.7). We found that the occurrence rate of the CMEs correlates with CBI relatively stronger at high latitudes (>=60) than at low latitudes (<=50). At low latitudes, the occurrence rate of the CMEs correlates relatively weaker with CBI than F10.7. There is a relatively stronger correlation relationship between CMEs, F10.7, and CBI during Solar Cycle 24(SC24) than Solar Cycle 23 (SC23). During SC23, the high-latitude CME occurrence rate lags behind F10.7 by three months, and during SC24, the low-latitude CME occurrence rate leads to the low-latitude CBI by one month. The correlation coefficient values turn out to be larger when the very faint CMEsare removed from the samples of the CDAW catalog. Based on our results, we may speculate that the source regions of the high/low-latitude CMEs may vary in height, and the process of magnetic energy accumulation and dissipation is from the lower to the upper atmosphere of the Sun. The temporal offsets between different indicators could help us better understand the physical processes responsible for the solar-terrestrial interactions.