We determined the direction and strength of the photospheric and lower chromospheric magnetic field in the umbra and penumbra of a sunspot from inversions of spectropolarimetric observations of photospheric lines at 617\,nm and 1565\,nm, and the chromospheric \ion{Ca}{ii} IR line at 854\,nm, respectively. We compare the magnetic field vector with the direction of 75 flow channels that harbor the chromospheric inverse Evershed effect (IEF) near their downflow points (DFPs) in the sunspot's penumbra. The azimuth and inclination of the IEF channels to the line of sight (LOS) were derived from spatial maps of the LOS velocity and line-core intensity of the \ion{Ca}{ii} IR line and a thermal inversion of the \ion{Ca}{ii} IR spectra to obtain temperature cubes. We find that the flow direction of the IEF near the DFPs is aligned with the photospheric magnetic field to within about $\pm$\,15\,deg. The IEF flow fibrils make an angle of 30--90\,deg to the local vertical with an average value of about 65\,deg. The average field strength at the DFPs is about 1.3\,kG. Our findings suggest that the IEF in the lower chromosphere is a field-aligned siphon flow, where the larger field strength at the inner footpoints together with the lower temperature in the penumbra causes the necessary gas pressure difference relative to the outer footpoints in the hotter quiet Sun with lower magnetic field strength. The IEF connects to magnetic field lines that are not horizontal like for the regular photospheric Evershed flow, but which continue upwards into the chromosphere indicating an "uncombed" penumbral structure.
我们研究超音速Evershed下降流在太阳黑子半影的高空间分辨率光谱偏振数据在Fe I 617.3 nm线与CRISP仪器在瑞典1米太阳望远镜。物理可观测量，如从线平分线和斯托克斯V零交叉波长计算的多普勒图，以及远红翼的斯托克斯V图，被用来寻找可能存在超音速Evershed下降流的区域。我们检索的LOS速度和磁场矢量在这些地区使用两个组件的反演所观察到的斯托克斯配置文件的帮助下的SIR代码。我们在这些区域的一生中跟踪它们，以研究它们的时间行为。最后，我们进行了统计分析检测到的超音速下降流，以表征其物理特性。超音速下降流包含在向外移动的紧凑斑块中，这些斑块位于中间和外部半影中。它们被观察为明亮的，圆形的结构，在半影细丝的外端，类似于半影颗粒。斑块在其生命周期中可能经历破碎和合并，甚至有些斑块是循环的。超音速下降流与强而垂直的磁场有关，与太阳黑子的磁场相比，磁场的极性相反。我们的研究结果表明，以超音速返回太阳表面的下行流在致密的深层突然停止并产生冲击。因此，这种冲击提高了温度，并被检测到作为一个明亮的颗粒在连续滤波图，这可以解释向外移动的颗粒在中间和外部半影的存在。
线轮廓的不对称性定义的Evershed效应在太阳黑子半影，突然消失在太阳黑子边界外的水平距离小于500公里，立即在黑暗的半影连续结构（“灯丝”）的最外端。这可以从非磁力线Ni I 5435.9（g=0.5）和Fe I 5434.5（g=0）中看出，它们虽然在300 km的垂直高度距离处形成，但在相同的空间位置处失去了它们的轮廓不对称性。被广泛接受的“天篷”图片与这一发现相冲突，相反，这表明与Evershed效应相关的气体运动消失了，同时在太阳黑子（半影）边界的连续强度下降。相应的下向流必须小于目前实现的空间分辨率（即，<0.5角秒），位于太阳黑子的最外边界。有人建议，这个位置标志着尖锐的阈值之间的均分动能和磁能密度在外部半影边界。
Spectropolarimetry of Sunspot Penumbrae -- A Comprehensive Study of the Evershed Effect Using High Resolution Data from the Space-Borne Solar Observatory HINODE
SUMER observations of the inverse Evershed effect in the transition region above a sunspot
目标。我们分析SUMER光谱扫描的活动区域NOAA 10923内的一个大的太阳黑子，获得2006年11月14日至15日，以确定太阳黑子大气在不同的高度/温度的形态和动态。研究方法：这里分析的数据包括在142.0 nm附近的连续光谱和在Si iv 140.2 nm，O iii 70.3 nm，N iv 76.5 nm，和O iv 79.0 nm谱线中的太阳分光图。高斯拟合观测到的配置文件提供了视线速度和多普勒宽度图。结果如下：数据显示，在过渡区温度高达0.18 MK的半影半径的大约两倍内的区域中，与逆Evershed流的存在相兼容的不对称下流型。的运动，高度不均匀的小尺度上，似乎发生在一个衣领的径向定向constentary结构，平均宽度小于1毫米的空间分辨率的SUMER和不同的等离子体速度的特点。假设气流是沿着场线流动的，我们推断出这样的场线相对于太阳表面倾斜10度至25度。
我们在太阳黑子的超半影外边界观测到了一个C级耀斑。耀斑是由一个新兴的磁双极区，是倾斜取向的超级半影原纤维。耀斑是由于出现的磁通量与超半影场的低高度磁重联导致逆Evershed流道及其上覆大气中的热多温度等离子体流而开始的。色球层中的逆Evershed流从超级半影开始向黑子方向流动，在半影的外边界结束。在逆Evershed通道中朝向太阳黑子的热等离子体流在H $α$波长中显示出比在不同温度下的等离子体发射高约10 km s $^{-1}$的速度，如在不同的AIA过滤器中所见。尽管这些速度比典型的逆埃弗谢德流速度高出约7倍，但在太阳黑子半影的外边界处，流动会减少。这表明携带逆Evershed流的超级半影场线在半影场线潜入太阳的边界处中断，并且这两组场线完全不同。在这两组场线的邻接处的典型磁场和等离子体性质的不连续性进一步导致特征磁声和阿尔文速度的不连续性，因此，停止等离子体流动进一步on.The多温度等离子体在逆Evershed通道中表现出\textbf{possible}纵向振荡最初在耀斑的发病期间，后来流向太阳黑子。在多温区的情况下，耀斑区上方的不同层具有超音速和亚音速的混合流。
We present the properties of the inverse Evershed flow (IEF) based on the center-to-limb variation of the plasma speed and loop geometry of chromospheric superpenumbral fibrils in eleven sunspots that were located at a wide range of heliocentric angles from 12 to 79 deg. The observations were acquired at the Dunn Solar Telescope in the spectral lines of Halpha at 656nm, CaII IR at 854 nm and HeI at 1083 nm. All sunspots display opposite line-of-sight (LOS) velocities on the limb and center side with a distinct shock signature near the outer penumbral edge. We developed a simplified flexible su…
The inverse Evershed flow (IEF) is a mass motion towards sunspots at chromospheric heights. We combined high-resolution observations of NOAA 12418 from the Dunn Solar Telescope and vector magnetic field measurements from the Helioseismic and Magnetic Imager (HMI) to determine the driver of the IEF. We derived chromospheric line-of-sight (LOS) velocities from spectra of H$α$ and Ca II IR. The HMI data were used in a non-force-free magnetic field extrapolation to track closed field lines near the sunspot in the active region. We determined their length and height, located their inner and outer f…
Traditionally, the strongest magnetic fields on the Sun have been measured in sunspot umbrae. More recently, however, much stronger fields have been measured at the ends of penumbral filaments carrying the Evershed and counter-Evershed flows. Superstrong fields have also been reported within a light bridge separating two umbrae of opposite polarities. We aim to accurately determine the strengths of the strongest fields in a light bridge using an advanced inversion technique and to investigate their detailed structure. We analyze observations from the spectropolarimeter on board the Hinode spac…
