A highly dynamic small-scale jet in a polar coronal hole

TL;DR

This study observes a highly dynamic polar coronal jet with multiple plasma ejections, complex morphological changes, and high-speed outflows, revealing intricate plasma behaviors and reconnection processes in the solar corona.

Contribution

It provides detailed high-resolution observations of plasma dynamics and morphological evolution in a polar coronal jet, highlighting the complexity of reconnection-driven jet phenomena.

Findings

Multiple plasma blobs propagate upwards at sound speed.

Super-sonic outflows reach ~230 km/s along the jet spire.

Jet undergoes transitions between standard and blowout eruptions.

Abstract

We present an observational study of the plasma dynamics at the base of a solar coronal jet, using high resolution extreme ultraviolet imaging data taken by the Extreme Ultraviolet Imager on board Solar Orbiter, and by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory. We observed multiple plasma ejection events over a period of $\sim$1 hour from a dome-like base that is ca.~4 Mm wide and is embedded in a polar coronal hole. Within the dome below the jet spire, multiple plasma blobs with sizes around 1--2 Mm propagate upwards to dome apex with speeds of the order of the sound speed (ca.~120~km~s$^{-1}$ ). Upon reaching the apex, some of these blobs initiate flows with similar speeds towards the other footpoint of the dome. At the same time, high speed super-sonic outflows ($\sim$230~km~s$^{-1}$) are detected along the jet spire. These outflows as well as the intensity near the dome apex appear to be repetitive. Furthermore, during its evolution, the jet undergoes many complex morphological changes including transitions between the standard and blowout type eruption. These new observational results highlight the underlying complexity of the reconnection process that powers these jets and also provide insights into the plasma response when subjected to rapid energy injection.