RESONANT ABSORPTION OF TRANSVERSE OSCILLATIONS AND ASSOCIATED HEATING IN A SOLAR PROMINENCE. II. NUMERICAL ASPECTS
RESONANT ABSORPTION OF TRANSVERSE OSCILLATIONS AND ASSOCIATED HEATING IN A SOLAR PROMINENCE. II. NUMERICAL ASPECTS
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DOI：
10.1088/0004-637x/809/1/72
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发表时间：
2015-06
期刊：
影响因子：
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通讯作者：
P. Antolin;T. Okamoto;B. Pontieu;Han Uitenbroek;T. Doorsselaere;Takaaki Yokoyama
中科院分区：
文献类型：
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作者：
P. Antolin;T. Okamoto;B. Pontieu;Han Uitenbroek;T. Doorsselaere;Takaaki Yokoyama
横向磁流体(MHD)波在太阳大气中无处不在，可能是产生太阳百万度外层大气的原因。然而，这些波的消散过程和加热的直接证据仍然难以捉摸。通过先进的数值模拟结合适当的日冕通量管正演模拟，我们给出了日冕等离子体中横向MHD波的观测特征。结果表明，这些特征具有线状的子结构、强的横向动力学相干性、天空平面运动和视线速度之间的位相差以及大部分通量管周围增强的谱线展宽和加热。共振吸收和开尔文-亥姆霍兹不稳定性(KHIS)之间发生了复杂的组合，KHI从共振层中提取能量，并通过涡旋和电流片将其耗散，这两个涡旋和电流片迅速退化为湍流。产生了向内扩大的边界，其中湍流保护了共振的特征动力学，从而保证了共振印记的可检测性。我们通过协调Hinode和界面区成像光谱仪的观测表明，所附文件中描述的特征与数值结果吻合得很好。
Transverse magnetohydrodynamic (MHD) waves are ubiquitous in the solar atmosphere and may be responsible for generating the Sun’s million-degree outer atmosphere. However, direct evidence of the dissipation process and heating from these waves remains elusive. Through advanced numerical simulations combined with appropriate forward modeling of a prominence flux tube, we provide the observational signatures of transverse MHD waves in prominence plasmas. We show that these signatures are characterized by a thread-like substructure, strong transverse dynamical coherence, an out-of-phase difference between plane-of-the-sky motions and line-of-sight velocities, and enhanced line broadening and heating around most of the flux tube. A complex combination between resonant absorption and Kelvin–Helmholtz instabilities (KHIs) takes place in which the KHI extracts the energy from the resonant layer and dissipates it through vortices and current sheets, which rapidly degenerate into turbulence. An inward enlargement of the boundary is produced in which the turbulent flows conserve the characteristic dynamics from the resonance, therefore guaranteeing detectability of the resonance imprints. We show that the features described in the accompanying paper through coordinated Hinode and Interface Region Imaging Spectrograph observations match the numerical results well.