Nowcast of an EUV dynamic spectrum during solar flares
Nowcast of an EUV dynamic spectrum during solar flares
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DOI：
10.1016/j.jastp.2020.105302
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发表时间：
2020-05
影响因子：
1.9
通讯作者：
T. Kawai;S. Imada;Shohei Nishimoto;Kyoko Watanabe;T. Kawate
中科院分区：
文献类型：
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作者：
T. Kawai;S. Imada;Shohei Nishimoto;Kyoko Watanabe;T. Kawate
除了X射线，太阳耀斑辐射的极端紫外线(EUV)还会导致严重的问题，如通信故障和卫星阻力。因此，迫切需要建立耀斑期间极紫外动光谱的预报方法。然而，近年来，由于缺乏仪器，极紫外动态光谱很少被观测到。因此，我们开发了一种新的方法，利用太阳动力学天文台/大气成像组合图像、数值模拟和原子数据库，将大型耀斑事件中观测到的软X射线光曲线转换为极紫外动态光谱。该模拟为强耀斑加热的日冕环提供了解决方案，原子数据库计算其动态光谱，包括X射线和极紫外光辐射。通过比较观测到的软X射线光曲线和模拟的软X射线光曲线，可以计算出转换所需的系数。我们将我们的新方法应用于2017年9月6日在活动区12673发生的三次耀斑。结果显示与耀斑辐射光谱模型的结果相似，并重建了太阳动力学天文台上的EUV可变性实验所观测到的一些EUV峰。
In addition to X-rays, extreme ultraviolet (EUV) rays radiated from solar flares can cause serious problems, such as communication failures and satellite drag. Therefore, methods for forecasting EUV dynamic spectra during flares are urgently required. Recently, however, owing to the lack of instruments, EUV dynamic spectra have rarely been observed. Hence, we develop a new method that converts the soft X-ray light curve observed during large flare events into an EUV dynamic spectrum by using theSolar Dynamics Observatory/Atmospheric Imaging Assemblyimages, a numerical simulation, and atomic database. The simulation provides the solution for a coronal loop that is heated by a strong flare, and the atomic database calculates its dynamic spectrum, including X-ray and EUV irradiances. The coefficients needed for the conversion can be calculated by comparing the observed soft X-ray light curve with that of the simulation. We apply our new method to three flares that occurred in the active region 12673 on September 06, 2017. The results show similarities to those of theFlare Irradiance Spectral Model, and reconstruct some of the EUV peaks observed by theEUV Variability Experimentonboard theSolar Dynamics Observatory.