Solar flare activity is characterized by different classification systems, both in optical and X-ray ranges. The most generally accepted classifications of solar flares describe important parameters of flares such as the maximum of brightness of the flare in the optical range – $$H_{\alpha }$$ H α flare class (change from F to B), area of the flare in $$H_{\alpha }$$ H α (change from S for areas less than 2 square degrees to 4 for areas more than 24.7 square degrees) and the maximum amplitude of the soft X-ray (SXR)-flux in the band 0.1–0.8 nm ( $$F_{0.1-0.8}^{\mathrm{max}}$$ F 0.1 - 0.8 max ) – X-ray flares of classes from C to X. A new classification parameter of solar flares is proposed here – the X-ray index of flare XI, based on GOES measurements of solar radiation in the SXR-range. The XI-index has a clear physical interpretation associated with the total flare energy in the SXR-range. XI is easily calculated for each flare with the use of available GOES data. The XI-index can be used along with other geoeffective parameters of Solar activity to assess both flares and coronal mass ejections that are connected with them.

中文翻译：

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基于软 X 射线最大通量和耀斑持续时间的太阳耀斑新分类参数

太阳耀斑活动的特点是在光学和 X 射线范围内都有不同的分类系统。最普遍接受的太阳耀斑分类描述了耀斑的重要参数，例如在光学范围内耀斑的最大亮度 – $$H_{\alpha }$$ H α 耀斑类别（从 F 到 B），面积$$H_{\alpha }$$ H α 中的耀斑（从小于 2 平方度的区域的 S 变为大于 24.7 平方度的区域的 4）和软 X 射线 (SXR) 通量的最大振幅在 0.1–0.8 nm 波段 ( $$F_{0.1-0.8}^{\mathrm{max}}$$ F 0.1 - 0.8 max ) – 从 C 到 X 类别的 X 射线耀斑。太阳的新分类参数这里提出了耀斑——耀斑 XI 的 X 射线指数，基于对 SXR 范围内太阳辐射的 GOES 测量。XI 指数具有与 SXR 范围内的总耀斑能量相关的明确物理解释。使用可用的 GOES 数据可以轻松计算每个耀斑的 XI。XI-index 可与太阳活动的其他地球有效参数一起使用，以评估与之相关的耀斑和日冕物质抛射。