Journal Article

Observational Study of Chromospheric Jets In and Around a Sunspot Observed by NVST and SDO

Wu, Guotang, Xu, Zhe, Zhang, Xinsheng, Wu, Zongyin, Xue, Zhike, Wang, Jincheng, Zhou, Yian, Yang, Liheng, Yang, Liping, Yan, Xiaoli, Dong, Qifan

2025

Overview

To better understand the characteristics, driving mechanisms, and potential heating contributions of chromospheric jets, we analyze two contrasting types: one originating from within the sunspot penumbra (inside jets) and the other originating from outside the penumbra (outside jets). Statistical analysis of 100 jets (50 inside jets and 50 outside jets) reveals that inside jets have a projected velocity range of 4–14 km s−1, a length range of 1–4 Mm, a width range of 0.2–0.6 Mm, and a lifetime range of 135–450 s, with mean values of 7.90 km s−1, 2.61 Mm, 0.41 Mm, and 260 s, respectively. About 52% of inside jets are associated with brightenings in Hα blue wing images, and some show high-temperature signatures, suggesting a connection with localized energy release. In contrast, outside jets have higher velocities (8–50 km s−1, average 19.04 km s−1), greater lengths (average 6.26 Mm, up to 27.27 Mm), slightly larger widths (average 0.46 Mm), and longer lifetimes (135–630 s, average 327 s). They typically originate from regions of opposite magnetic polarities and are associated with magnetic flux emergence and extreme-ultraviolet brightenings. Some outside jets correspond to coronal jets with inverted Y-shaped structures and temperatures exceeding one million Kelvin. Our results suggest that both jet types are driven by magnetic reconnection occurring in distinct magnetic field configurations and contribute to chromospheric and coronal heating.

• Publisher: IOP Publishing
• Subject: Coronal heating / Heating / High temperature / Jets / Magnetic field configurations / Magnetic fields / Magnetic flux / Magnetic reconnection / Observational studies / Physical properties / Physics / Solar physics / Statistical analysis / Sunspots / Telescopes