IRIS Observational Approach to the Oscillatory and Damping Nature of Network and Internetwork Chromosphere Small-Scale Brightening (SSBs) and Their Unusual Dynamical and Morphological Differences in Different Regions on the Solar Disk

Abstract

One of the most exciting benefits of solar small-scale brightening is their oscillations. This study investigated the properties of small-scale brightening (SSBs) in different regions of the Sun and found that there are differences and similarities in the properties of oscillated and non-oscillated SSBs in different regions of the Sun, including quiet Sun (QS), the adjacent to active regions (AAR), and coronal hole (CH).

The damping per period (Q-factor) and maximum Doppler velocity of SSBs varied depending on the region, with the less bright internetwork SSBs in QS having lower damping time (120 seconds) and higher maximum Doppler velocities (47 km s⁻¹) compared to the brighter network SSBs (with 216 seconds & 37 km s⁻¹, respectively), while in AAR, internetwork SSBs tend to have higher damping time (about of 220 seconds) and wider maximum Doppler velocity (10 to 140 km s⁻¹) ranges compared to network SSBs (130 seconds and 10 to 85 km s⁻¹). In CH, both types of SSBs show similar damping time (120 seconds), but internetwork SSBs tend to have higher maximum Doppler velocities (100 km s⁻¹) compared to network SSBs (85 km s⁻¹).

It was also pointed out that the majority of network SSBs in AARs are in the overdamping mode, while in QS, internetwork SSBs demonstrate overdamping behavior and oscillated network SSBs exhibit critical damping behavior. However, it is important to remember that the physical mechanisms underlying the damping of SSBs may vary depending on the local plasma conditions and magnetic environment.