Occurrence Rate of Radio-Loud and Halo CMEs in Solar Cycle 25: Prediction Using their Correlation with the Sunspot Number

Abstract

Solar coronal mass ejections (CMEs) are known for their space-weather and geomagnetic consequences. Among all CMEs, the so-called radio-loud (RL) and halo CMEs are considered the most energetic in the sense that they are usually faster and wider than the general population of CMEs. Hence the study of RL and halo CMEs has become important and the prediction of their occurrence rate in a future cycle will help their forecasting. In this article we predict the occurrence rates of RL and halo CMEs in Solar Cycle (SC) 25, obtaining good correlations between the numbers of RL and halo CMEs in each year and the yearly mean sunspot number in the previous two cycles. The values of the sunspot number predicted by NOAA/NASA for SC 25 are considered to be representative and the corresponding numbers of RL and halo CMEs are determined using linear relations. Our results show that the maximum number of RL and halo CMEs will be around 39 ±3 and 45 ±4 , respectively. Removing backside events, a set of front-side events is also considered separately and front-side events in SC 25 are also predicted. The peak values of front-side RL and halo events have been estimated to be around 31 ±3 and 29 ±3 , respectively. These results are discussed in comparison with the predicted sunspot number values by different authors.