Statistical study of network jets observed in the solar transition region: A comparison between coronal holes and quiet sun regions

TL;DR

This study compares the properties of network jets in coronal holes and quiet-sun regions, revealing similarities in their generation mechanisms but differences in their speeds and lengths due to magnetic field configurations.

Contribution

It provides a detailed statistical analysis of network jets in different solar regions, highlighting regional differences and commonalities in their physical characteristics.

Findings

Coronal-hole jets are faster and longer than quiet-sun jets.

Both regions show similar increases in foot-point brightness of jets.

Magnetic configuration differences influence jet properties.

Abstract

Recent IRIS observations have revealed a prevalence of intermittent small-scale jets with apparent speeds of 80 - 250 km s$^{-1}$, emanating from small-scale bright regions inside network boundaries of coronal holes. We find that these network jets appear not only in coronal holes but also in quiet-sun regions. Using IRIS 1330A (C II) slit-jaw images, we extract several parameters of these network jets, e.g. apparent speed, length, lifetime and increase in foot-point brightness. Using several observations, we find that some properties of the jets are very similar but others are obviously different between the quiet sun and coronal holes. For example, our study shows that the coronal-hole jets appear to be faster and longer than those in the quiet sun. This can be directly attributed to a difference in the magnetic configuration of the two regions with open magnetic field lines rooted in coronal holes and magnetic loops often present in quiet sun. We have also detected compact bright loops, likely transition region loops, mostly in quiet sun. These small loop-like regions are generally devoid of network jets. In spite of different magnetic structures in the coronal hole and quiet sun in the transition region, there appears to be no substantial difference for the increase in foot-point brightness of the jets, which suggests that the generation mechanism of these network jets is likely the same in both regions.