Characterization of shock wave signatures at millimetre wavelengths from Bifrost simulations.
Characterization of shock wave signatures at millimetre wavelengths from Bifrost simulations.
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Bifrost 模拟中毫米波长冲击波特征的表征。
DOI：
10.1098/rsta.2020.0185
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Eklund H
中科院分区：
文献类型：
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作者：
Eklund H
毫米波长的观测为研究太阳色球层的小尺度动态提供了宝贵的工具。我们评估了存在传播冲击波时大气的物理条件，并将其与mm波长辐射中可观察到的特征联系起来，为mm波长观测的基础物理学提供了有价值的见解。一个现实的数值模拟从三维辐射磁流体动力学代码彩虹被用来解释冲击波传播引起的大气变化。高节奏（1秒）的时间序列的亮度温度（Tb）的地图计算与高级辐射传输代码在波长1.309毫米和1.204毫米，这代表的阿塔卡马大毫米/亚毫米阵列（阿尔马）的光谱带6的相对侧。给出了激波传播的一个例子。亮温显示出强烈的冲击波信号，地层高度在约0.7和1.4微米之间变化很大。结果表明，毫米亮度温度有效地跟踪向上传播的激波在中间色球层。此外，我们表明，亮度温度的梯度之间的波长在阿尔马带6可以潜在地被用作诊断工具，在了解小尺度动态采样layer.This文章的一部分，西奥墨菲会议的问题“高分辨率波动力学在低太阳大气层”。
Observations at millimetre wavelengths provide a valuable tool to study the small-scale dynamics in the solar chromosphere. We evaluate the physical conditions of the atmosphere in the presence of a propagating shock wave and link that to the observable signatures in mm-wavelength radiation, providing valuable insights into the underlying physics of mm-wavelength observations. A realistic numerical simulation from the three-dimensional radiative magnetohydrodynamic code Bifrost is used to interpret changes in the atmosphere caused by shock wave propagation. High-cadence (1 s) time series of brightness temperature (Tb) maps are calculated with the Advanced Radiative Transfer code at the wavelengths 1.309 mm and 1.204 mm, which represents opposite sides of spectral band 6 of the Atacama Large Millimeter/submillimeter Array (ALMA). An example of shock wave propagation is presented. The brightness temperatures show a strong shock wave signature with large variation in formation height between approximately 0.7 and 1.4 Mm. The results demonstrate that millimetre brightness temperatures efficiently track upwardly propagating shock waves in the middle chromosphere. In addition, we show that the gradient of the brightness temperature between wavelengths within ALMA band 6 can potentially be used as a diagnostics tool in understanding the small-scale dynamics at the sampled layers.This article is part of the Theo Murphy meeting issue ‘High-resolution wave dynamics in the lower solar atmosphere’.