We analyze the coronal elemental abundances during a small flare using Hinode/EIS observations. Compared to the preflare elemental abundances, we observed a strong increase in coronal abundance of Ca xiv 193.84 Å, an emission line with low first ionization potential (FIP < 10 eV), as quantified by the ratio Ca/Ar during the flare. This is in contrast to the unchanged abundance ratio observed using Si x 258.38 Å/S x 264.23 Å. We propose two different mechanisms to explain the different composition results. First, the small flare-induced heating could have ionized S, but not the noble gas Ar, so that the flare-driven Alfvn waves brought up Si, S, and Ca in tandem via the ponderomotive force which acts on ions. Second, the location of the flare in strong magnetic fields between two sunspots may suggest fractionation occurred in the low chromosphere, where the background gas is neutral H. In this region, high-FIP S could behave more like a low-FIP than a high-FIP element. The physical interpretations proposed generate new insights into the evolution of plasma abundances in the solar atmosphere during flaring, and suggests that current models must be updated to reflect dynamic rather than just static scenarios.

我们使用 Hinode/EIS 观测分析了小型耀斑期间的日冕元素丰度。与耀斑前的元素丰度相比，我们观察到 Ca xiv 193.84 Å 的日冕丰度显着增加，这是一条具有低第一电离势 (FIP < 10 eV) 的发射线，由耀斑期间的 Ca/Ar 比率量化。这与使用 Si x 258.38 Å/S x观察到的丰度比不变形成对比264.23 埃。我们提出了两种不同的机制来解释不同的合成结果。首先，小耀斑引起的加热可能使 S 电离，而不是惰性气体 Ar，因此耀斑驱动的 Alfvn 波通过作用于离子的有质动力将 Si、S 和 Ca 串联起来。其次，两个太阳黑子之间强磁场中耀斑的位置可能表明在低色球层发生了分馏，其中背景气体是中性 H。在这个区域，高 FIP S 可能表现得更像低 FIP 而不是高-FIP 元素。提出的物理解释对燃烧期间太阳大气中等离子体丰度的演变产生了新的见解，并表明必须更新当前模型以反映动态而不仅仅是静态场景。