Type IV Radio Bursts and Associated Active Regions in Sunspot Cycle 24

Abstract

AbstractWe study the association of solar Type IV radio bursts with the location of active regions on the Sun during Solar Cycle 24. The active regions associated with moving and stationary Type IV bursts are categorized as close to disk center and far from disk center, based on their location on the solar surface (i.e. $\leq 45^{\circ}$ ≤ 45 ∘ or $\geq 45^{\circ}$ ≥ 45 ∘ , respectively). The location of active regions associated with Type IV bursts accompanied with coronal mass ejections (CMEs) are also studied. We found that ≈ 30 – 40% of the active regions are located far from disk center for all the bursts. However, it is found that most of the active regions associated with stationary Type IV bursts are close to disk center (≈ 60 – 70%). The active regions associated with moving Type IV bursts are more evenly distributed across the surface, i.e. $\approx 56 \%$ ≈ 56 % and $\approx 44 \%$ ≈ 44 % , close to disk center and far from disk center, respectively. The fact that most of the bursts have active regions close to disk center indicates that these bursts can be used to obtain physical properties such as electron density and magnetic fields of the CMEs responsible for geomagnetic storms.