Abstracts Details


First Name * : Ding
Last Name * : Yuan
Affiliation * : Harbin Institute of Technology, Shenzhen
Abstract Type * : Oral
Title * : Multi-layered Kelvin-Helmholtz Instability in the Solar Corona
Author(s) * : Ding Yuan;Yuandeng Shen , Yu Liu , Hongbo Li , Xueshang Feng ,Rony Keppens
Abstract Session * : Chromospheric dynamics
Abstract * : The Kelvin-Helmholtz (KH) instability is commonly found in many astrophysical, laboratory, and space plasmas. It could mix plasma components of different properties and convert dynamic fluid energy from large scale structure to smaller ones. In this study, we combined the Solar Dynamic Observatories (SDO) / Atmospheric Imaging Assembly (AIA) and the ground-based New Vacuum Solar Telescope (NVST) to observe the plasma dynamics associated with active region 12673 on 09 September 2017. In this multi-temperature view, we identified three adjacent layers of plasma flowing at different speeds and detected KH instabilities at the interfaces. We could unambiguously track a typical KH vortex and were able to measure its motion. We found that the speed of this vortex suddenly tripled at a certain stage. This acceleration was synchronized with the enhancements in emission measure and average intensity of the 193 \AA{} data. We interpret this as evidence that KH instability triggers plasma heating. The intriguing feature in this event is that the KH instability observed in the NVST channel was nearly complementary to that in the AIA 193 \AA{}. Such a multi-thermal energy exchange process is easily overlooked in previous studies, as the cold plasma component is usually not visible, i.e., the extreme ultraviolet emission is negligible in low temperature plasma. Our finding indicates that embedded cold layers could interact with hot plasma as a kind of ghost matter. We speculate that this process could occur at a variety of length scales and could contribute to plasma heating.