Quasiperiodic Energy Release and Jets at the Base of Solar Coronal Plumes

TL;DR

This paper reveals that quasiperiodic tiny jets, called jetlets, at the base of solar coronal plumes are likely driven by magnetic reconnection modulated by p-mode oscillations, contributing to solar wind mass and dynamics.

Contribution

It provides high-resolution observations linking jetlets to magnetic reconnection and p-mode oscillations, elucidating their role in solar wind origin and plume dynamics.

Findings

Jetlets are associated with transient brightenings and plasma heating.

Jetlets are modulated by 3-5 minute p-mode oscillations.

Jetlets contribute to solar wind mass and may explain switchbacks.

Abstract

Coronal plumes are long, ray-like, open structures, which have been considered as possible sources for the solar wind. Their origin in the largely unipolar coronal holes has long been a mystery. Earlier spectroscopic and imaging observations revealed blue-shifted plasma and propagating disturbances (PDs) in plumes that are widely interpreted in terms of flows and/or propagating slow-mode waves, but these interpretations (flows vs waves) remain under debate. Recently we discovered an important clue about plume internal structure: dynamic filamentary features called plumelets, which account for most of the plume emission. Here we present high-resolution observations from the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) and the Interface Region Imaging Spectrograph (IRIS) that revealed numerous, quasiperiodic, tiny jets (so-called jetlets) associated with transient brightening, flows, and plasma heating at the chromospheric footpoints of the plumelets. By analogy to larger coronal jets, these jetlets are most likely produced within the plume base by magnetic reconnection between closed and open flux at stressed 3D null points. The jetlet-associated brightenings are in phase with plumelet-associated PDs, and vary with a period of about 3 to 5 minutes, which is remarkably consistent with the photospheric/chromospheric p-mode oscillation. This reconnection at the open-closed boundary in the chromosphere/transition region is likely modulated or driven by local manifestations of the global p-mode waves. The jetlets extend upward to become plumelets, contribute mass to the solar wind, and may be sources of the switchbacks recently detected by the Parker Solar Probe.