Forecast of a Daily Halo CME Occurrence Probability Depending on Class and Area Change of the Associated Sunspot

Abstract

We investigate the halo (partial and full) coronal mass ejection (CME) occurrence probability depending on class and area change of the associated sunspot using front-side halo CMEs from 1996 to 2011. We select the most halo CME-productive 14 sunspot classifications: Cao, Cko, Dai, Dao, Dko, Dki, Dkc, Eao, Eai, Eko, Eki, Ekc, Fki, and Fkc. For each class, we assign three subgroups according to sunspot class area change: "Decrease", "Steady", or "Increase". As a result, in the case of asymmetric (k) and compact (c) groups, their CME occurrence probabilities increase. We also find that the halo-CME occurrence probabilities for the "Increase" subgroups are noticeably higher than those for the other subgroups. Our results demonstrate statistically that magnetic-flux emergence or cancellation enhances CME occurrence. We expect that this model can be routinely operated to forecast the halo-CME occurrence probability.