Disappearance of a coronal hole induced by a filament activation

TL;DR

This study documents a rare case where a filament activation directly interacted with and caused the disappearance of a coronal hole through magnetic reconnection, providing insights into solar magnetic dynamics.

Contribution

It presents the first detailed observation of direct magnetic interaction between an activating filament and a coronal hole, linking filament intrusion to coronal hole disappearance.

Findings

Filament intrusion caused the coronal hole to shrink and vanish.

Coronal dimmings D1 and D2 persisted after the CH disappeared.

Magnetic extrapolation suggests interchange reconnection as the disappearance mechanism.

Abstract

We present a rare observation of direct magnetic interaction between an activating filament and a coronal hole (CH). The filament was a quiescent one located at the northwest of the CH. It underwent a nonradial activation, during which filament material constantly fell and intruded into the CH. As a result, the CH was clearly destroyed by the intrusion. Brightenings appeared at the boundaries and in the interior of the CH, meanwhile, its west boundaries began to retreat and the area gradually shrank. It is noted that the CH went on shrinking after the end of the intrusion and finally disappeared entirely. Following the filament activation, three coronal dimmings (D1-D3) were formed, among which D1 and D2 persisted throughout the complete disappearance of the CH. The derived coronal magnetic configuration shows that the filament was located below an extended loop system which obviously linked D1 to D2. By comparison with this result of extrapolation, our observations imply that the interaction between the filament and the CH involved direct intrusion of the filament material to the CH and the disappearance of the CH might be due to interchange reconnection between the expanding loop system and the CH's open field.