An EUV jet driven by a series of transition region micro-jets

TL;DR

This study observes how a large EUV jet in the solar atmosphere is driven by a series of smaller transition region micro-jets, highlighting the role of magnetic reconnections and flux ropes in jet formation.

Contribution

It reveals the connection between micro-scale transition region jets and larger EUV jets, emphasizing the importance of small-scale magnetic dynamics in solar eruptions.

Findings

TR micro-jets are linked to changes in micro-loop geometry.

A bundle of TR flux ropes connects micro-jets to the EUV jet base.

Magnetic reconnection facilitates the rise of flux ropes, triggering the EUV jet.

Abstract

Jets are one of the most common eruptive events in the solar atmosphere, and they are believed to be important in the context of coronal heating and solar wind acceleration. We present an observational study on a sequence of jets with the data acquired with the Solar Dynamics Observatory (SDO) and the Interface Region Imaging Spectrograph (IRIS). This sequence is peculiar in that an EUV jet, $\sim29\arcsec$ long and with a dome-like base, appears to be a consequence of a series of transition region (TR) micro-jets that are a few arcsecs in length.We find that the occurrence of any TR micro-jets is always associated with the change of geometry of micro-loops at the footpoints of the microjets. A bundle of TR flux ropes is seen to link a TR micro-jet to the dome-like structure at the base of the EUV jet. This bundle rises as a response to the TR micro-jets, with the rising motion eventually triggering the EUV jet. We propose a scenario involving a set of magnetic reconnections, in which the series of TR micro-jets are associated with the processes to remove the constraints to the TR flux ropes and thus allow them to rise and trigger the EUV jet. Our study demonstrates that small-scale dynamics in the lower solar atmosphere are crucial in understanding the energy and mass connection between the corona and the solar lower atmosphere, even though many of them might not pump mass and energy to the corona directly.