Potential Solar Precursors to Magnetic Switchbacks.

Abstract

The origin of magnetic switchbacks-large-amplitude, spherically polarized magnetic-field fluctuations with local polarity inversions shown to be nearly ubiquitous in the inner heliosphere by Parker Solar Probe-is presently one of the most outstanding open questions in solar and heliospheric science. The occurrence of these structures in the young solar wind is a topic of active research, focusing not only on their characteristics and evolution but also on unraveling the puzzle of their origin. We first discuss the potential influence on switchback (SB) formation of large-scale coronal dynamics and restructuring processes that shape and regulate the extended solar corona. Following that, we review the dynamics, physical properties, occurrence rate, and energetics of numerous possible precursor small-scale dynamic events that occur throughout the solar atmosphere, emphasizing their possible roles in creating SBs. Finally, we discuss some recent studies attempting to connect in situ observations of SBs and SB patches with remote-sensing observations, and the related challenges in identifying solar wind source regions precisely and linking in situ observations to transient solar phenomena. We also clarify the terminology used by the solar community to describe small-scale solar phenomena.