Kumar Pankaj, Karpen Judith T, Antiochos Spiro K, Wyper Peter F, Devore C Richard, Deforest Craig E
Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA.
Department of Mathematical Sciences, Durham University, Durham DH1 3LE, UK and.
Astrophys J. 2018 Feb 20;854(2). doi: 10.3847/1538-4357/aaab4f. Epub 2018 Feb 21.
Small, impulsive jets commonly occur throughout the solar corona, but are especially visible in coronal holes. Evidence is mounting that jets are part of a continuum of eruptions that extends to much larger coronal mass ejections and eruptive flares. Because coronal-hole jets originate in relatively simple magnetic structures, they offer an ideal testbed for theories of energy buildup and release in the full range of solar eruptions. We analyzed an equatorial coronal-hole jet observed by SDO/AIA on 09 January 2014, in which the magnetic-field structure was consistent with the embedded-bipole topology that we identified and modeled previously as an origin of coronal jets. In addition, this event contained a mini-filament, which led to important insights into the energy storage and release mechanisms. SDO/HMI magnetograms revealed footpoint motions in the primary minority-polarity region at the eruption site, but show negligible flux emergence or cancellation for at least 16 hours before the eruption. Therefore, the free energy powering this jet probably came from magnetic shear concentrated at the polarity inversion line within the embedded bipole. We find that the observed activity sequence and its interpretation closely match the predictions of the breakout jet model, strongly supporting the hypothesis that the breakout model can explain solar eruptions on a wide range of scales.
小尺度的脉冲式喷流普遍存在于整个日冕中,不过在冕洞中尤为明显。越来越多的证据表明,喷流是一系列喷发活动的一部分,这些喷发活动一直延伸到规模大得多的日冕物质抛射和爆发耀斑。由于冕洞喷流起源于相对简单的磁场结构,它们为研究整个太阳喷发过程中的能量积累和释放理论提供了理想的试验平台。我们分析了2014年1月9日太阳动力学观测台(SDO)/大气成像组件(AIA)观测到的一个赤道冕洞喷流,其磁场结构与我们之前识别并建模为冕洞喷流起源的嵌入双极拓扑结构一致。此外,该事件包含一个小暗条,这为能量存储和释放机制提供了重要见解。SDO/日震磁像仪(HMI)的磁图显示了喷发区域主要少数极性区域的足点运动,但在喷发前至少16小时内,通量浮现或抵消现象可忽略不计。因此,为这个喷流提供能量的自由能可能来自集中在嵌入双极内极性反转线上的磁切变。我们发现观测到的活动序列及其解释与爆发喷流模型的预测密切匹配,有力地支持了爆发模型能够解释各种尺度太阳喷发的假设。