On the occurrence of type IV solar radio bursts in the solar cycle 24 and their association with coronal mass ejections
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Solar activity, in particular coronal mass ejections, are often accompanied by bursts of radiation at meter wavelengths, some of which are long duration and broadband in nature, such as type IV radio bursts. However, the association of type IV bursts with coronal mass ejections is still not well understood. We performed the first statistical study of type IV solar radio bursts in the solar cycle 24. Our studies include a total of 445 type IV radio bursts that occurred during this solar cycle. Our results show that ~56 % of type IV bursts were accompanied by CMEs, based on a temporal association with white-light CME observations. Our results indicated that ~65 % bursts had source region on the disk and ~35 % bursts had source region on the limb. Our studies also suggests that type IV bursts can occur with both ‘Fast’ (≥ 500 km/s) and ‘Slow’ (< 500 km/s) CMEs, however most of the type IV bursts (~ 66 %) were associated with ‘Wide’ (≥ 60 º) CMEs. Only ~43 % of the type IV bursts in this solar cycle were associated with ‘Fast and Wide’ CMEs. These results are unlike the majority of type II radio bursts that are mostly associated with ‘Fast and Wide’ CMEs.