Pathways of large-scale magnetic couplings between solar coronal events

TL;DR

This study investigates the large-scale magnetic couplings between solar coronal events, highlighting their causal relationships, the global nature of the coronal magnetic field, and implications for modeling solar phenomena.

Contribution

It provides case studies demonstrating various coupling processes and emphasizes the importance of global magnetic field understanding for solar eruption modeling.

Findings

Physical linkages between coronal events do occur but are infrequent.

Post-eruption corona reconfiguration lasts longer than the average interval between CMEs.

The coronal magnetic field is intrinsically global, affecting solar wind and energetic particle propagation.

Abstract

The high-cadence, comprehensive view of the solar corona by SDO/AIA shows many events that are widely separated in space while occurring close together in time. In some cases, sets of coronal events are evidently causally related, while in many other instances indirect evidence can be found. We present case studies to highlight a variety of coupling processes involved in coronal events. We find that physical linkages between events do occur, but concur with earlier studies that these couplings appear to be crucial to understanding the initiation of major eruptive or explosive phenomena relatively infrequently. We note that the post-eruption reconfiguration time scale of the large-scale corona, estimated from the EUV afterglow, is on average longer than the mean time between CMEs, so that many CMEs originate from a corona that is still adjusting from a previous event. We argue that the coronal field is intrinsically global: current systems build up over days to months, the relaxation after eruptions continues over many hours, and evolving connections easily span much of a hemisphere. This needs to be reflected in our modeling of the connections from the solar surface into the heliosphere to properly model the solar wind, its perturbations, and the generation and propagation of solar energetic particles. However, the large-scale field cannot be constructed reliably by currently available observational resources. We assess the potential of high-quality observations from beyond Earth's perspective and advanced global modeling to understand the couplings between coronal events in the context of CMEs and solar energetic particle events.