The chromospheric Lyman‐alpha line of neutral hydrogen (Lyα; 1216 Å) is the strongest emission line in the solar spectrum. Fluctuations in Lyα are known to drive changes in planetary atmospheres, although few instruments have had the ability to capture rapid Lyα enhancements during solar flares. In this paper, we describe flare‐associated emissions via a statistical study of 477 M‐ and X‐class flares as observed by the Extreme UltraViolet Sensor on board the 15th Geostationary Operational Environmental Satellite, which has been monitoring the full‐disk solar Lyα irradiance on 10‐s timescales over the course of Solar Cycle 24. The vast majority (95%) of these flares produced Lyα enhancements of 10% or less above background levels, with a maximum increase of ∼30%. The irradiance in Lyα was found to exceed that of the 1–8 Å X‐ray irradiance by as much as two orders of magnitude in some cases, although flares that occurred closer to the solar limb were found to exhibit less of a Lyα enhancement. This center‐to‐limb variation was verified through a joint, stereoscopic observation of an X‐class flare that appeared near the limb as viewed from Earth, but close to disk center as viewed by the MAVEN spacecraft in orbit around Mars. The frequency distribution of peak Lyα was found to have a power‐law slope of 2.8±0.27. We also show that increased Lyα flux is closely correlated with induced currents in the ionospheric E‐layer through the detection of the solar flare effect as observed by the Kakioka magnetometer.

中文翻译：

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使用GOES-15 / EUVS-E在整个太阳周期的太阳耀斑过程中的Lyman-alpha变异24

中性氢气的色球莱曼-阿尔法线（Ly的α ; 1216 a）是在太阳光谱的最强发射线。在Ly的波动α已知推动行星大气层的变化，虽然一些仪器不得不捕捉快速Ly的能力α期间，太阳耀斑增强。在本文中，我们通过在船上观察到极紫外传感器15日地球静止业务环境卫星，一直在监测的全磁盘太阳能Ly的477 M-和X级耀斑的统计研究描述发作相关的排放量α辐照这些耀斑的10秒时间尺度上太阳周期24的过程中，绝大多数（95％）产生的Ly的α的10％的增强或以上较少的背景水平，的最大增加〜 30％。在Ly的辐照度α被发现超过了1-8埃的X射线辐照的通过在某些情况下，幅度高达两个数量级，虽然发现发生接近太阳能肢耀斑表现出Ly的少α增强。这种中心到边缘的变化是通过对X级耀斑的联合，立体观察而得到证实的，该X级耀斑从地球上观察时出现在四肢附近，但在火星周围的MAVEN航天器的观察中，接近磁盘中心。峰Ly的频率分布α被发现具有的幂律斜率2.8±0.27。我们还表明，增加Ly的α 通过Kakioka磁力计观测到的太阳耀斑效应，通量与电离层E层中的感应电流紧密相关。