In recent years, coronal loops have been the focus of studies related to the damping of different magnetohydrodynamic (MHD) surface waves and their connection with coronal seismology and wave heating. For a better understanding of wave heating, we need to take into account the effects of different dissipation coefficients such as resistivity and viscosity, the importance of the loop physical characteristics, and the ways gravity can factor into the evolution of these phenomena. We aim to map the sites of energy dissipation from transverse waves in coronal loops in the presence and absence of gravitational stratification and to compare ideal, resistive, and viscous MHD. Using the PLUTO code, we performed 3D MHD simulations of kink waves in single, straight, density-enhanced coronal flux tubes of multiple temperatures. We see the creation of spatially expanded Kelvin-Helmholtz eddies along the loop, which deform the initial monolithic loop profile. For the case of driven oscillations, the Kelvin-Helmholtz instability develops despite physical dissipation, unless very high values of shear viscosity are used. Energy dissipation gets its highest values near the apex, but is present all along the loop. We observe an increased efficiency of wave heating once the kinetic energy saturates at the later stages of the simulation and a turbulent density profile has developed. The inclusion of gravity greatly alters the dynamic evolution of our systems and should not be ignored in future studies. Stronger physical dissipation leads to stronger wave heating in our set-ups. Finally, once the kinetic energy of the oscillating loop starts saturating, all the excess input energy turns into internal energy, resulting in more efficient wave heating.
Acoustic oscillations in the field-free, gravitationally stratified Acoustic oscillations in the field-free, gravitationally stratified cavities under solar bipolar magnetic canopies
Alfvénic Motions in a Stratified Open Flux Tube: Transition from Propagating to Locally Standing Motions and Implications for the Kelvin-Helmholtz Instability
Institute of Frontier and Interdisciplinary Science, Shandong University（山东大学前沿交叉科学研究院）；Shandong Key Laboratory of Space Environment and Exploration Technology, Institute of Space Sciences, Shandong University（山东大学空间科学学院山东省空间环境与探测技术重点实验室）；School of Earth and Space Sciences, Peking University（北京大学地球与空间科学学院）；Centre for mathematical Plasma Astrophysics (CmPA), Department of Mathematics, KU Leuven（荷语鲁汶大学数学系数学等离子体天体物理中心）
The Ambipolar electric field in multispecies plasma atmospheres: effects of alpha particles and stochastic heating
LIRA, Observatoire de Paris, Université PSL, Sorbonne Université, Université Paris Cité, CY Cergy Paris Université, CNRS（巴黎天文台，巴黎文理研究大学，索邦大学，巴黎西岱大学，塞吉-蓬图瓦兹大学，法国国家科学研究中心）；Mullard Space Science Laboratory, University College London（穆拉德空间科学实验室，伦敦大学学院）
Investigating `dark' energy in the solar corona using forward modeling of MHD waves
现在已经很好地确定了阿尔夫维尼克波在日冕中是普遍存在的。然而，在日冕中多普勒速度测量估计的Alfvénic波能量被发现是四个数量级小于估计的非热线宽。McIntosh & De Pontieu（2012）认为，这种能量差异可能是由于几种振荡结构的视线（LOS）叠加造成的，这可能导致阿尔夫维尼克波振幅和能量被低估。McIntosh & De Pontieu（2012）将这种日冕能量称为“暗”或“隐藏”能量。然而，他们的模拟需要使用一个额外的、未知的阿尔夫维尼克波能量源，以提供与日冕非热谱线宽度测量的一致性。在这项研究中，我们调查的要求，这个未知的额外的“暗”能源在日冕中使用重力分层的三维磁流体动力学（MHD）模拟传播波。我们激发横向MHD波，并产生合成观测的Fe XIII发射线。我们建立了LOS叠加大大降低了多普勒速度幅度，增加了非热线宽。重要的是，我们的模型产生的多普勒速度和非热线宽之间观察到的楔形相关性。我们发现，观测到的波能仅为真实波能的0.2- 1%，解释了2-3个数量级的能量差异。我们最终确定，真正的波能量隐藏在非热线宽。因此，我们的研究结果排除了太阳日冕中额外的“暗”能量的要求。
The Effect of Gravitational Stratification on Kink Oscillations in Curved Coronal Loops
Institute of Frontier and Interdisciplinary Science, Shandong University（山东大学前沿交叉科学研究中心）；Shandong Key Laboratory of Space Environment and Exploration Technology, Institute of Space Sciences, Shandong University（山东大学空间科学学院）
Modeling the Excitation, Propagation and Damping of Quasi-Periodic Fast Magnetosonic Waves in Realistic Coronal Active Region Magnetic Field Structures
Catholic University of America（美国天主教大学）；NASA Goddard Space Flight Center（NASA戈达德太空飞行中心）；Tel Aviv University（特拉维夫大学）；University of Hawaii at Mānoa（夏威夷大学马诺阿分校）；Lockheed Martin Solar and Astrophysics Laboratory（洛克希德·马丁太阳与天体物理实验室）
