Context. High resolution magnetic field measurements are routinely done only in the solar photosphere. Higher layers like the chromosphere and corona can be modeled by extrapolating the photospheric magnetic field upward. In the solar corona, plasma forces can be neglected and the Lorentz force vanishes. This is not the case in the upper photosphere and chromosphere where magnetic and non-magnetic forces are equally important. One way to deal with this problem is to compute the plasma and magnetic field self-consistently with a magnetohydrostatic (MHS) model.
Aims. We aim to derive the magnetic field, plasma pressure and density of AR11768 by applying the newly developed extrapolation technique to the SUNRISE/IMaX data.
Methods. An optimization method is used for the MHS modeling. The initial conditions consist of a nonlinear force-free field (NLFFF) and a gravity-stratified atmosphere.
Results. In the non-force-free layer, which is spatially resolved by the new code, Lorentz forces are effectively balanced by the gas pressure gradient force and the gravity force. The pressure and density are depleted in strong field regions, which is consistent with observations. Denser plasma, however, is also observed at some parts of the active region edges. In the chromosphere, the fibril-like plasma structures trace the magnetic field nicely. Bright points in SUNRISE/SuFI 3000 {$Å$} images are often accompanied by the plasma pressure and electric current concentrations. In addition, the average of angle between MHS field lines and the selected chromospheric fibrils is $11.8^\circ$, which is smaller than those computed from the NLFFF model ($15.7^\circ$) and linear MHS model ($20.9^\circ$). This indicates that the MHS solution provides a better representation of the magnetic field in the chromosphere.
Supersonic Magnetic Upflows in Granular Cells Observed with Sunrise/IMaX
利用“日出”平流层气球望远镜上的IMaX仪器，我们探测到了太阳光球层颗粒内Fe I 5250.217谱线周围极移的偏振信号。我们解释与这些事件相对应的超音速和磁上升流的速度。此外，它们还与相反极性和高度倾斜的磁场的出现有关。这表明，它们是通过颗粒上升流重新连接新兴的磁环而产生的。这些事件占据的平均面积为0.046弧秒$^2$，持续约80秒，较大的事件具有较长的寿命。这些超音速事件以每秒每角秒$^{2}$发生$1.3\times10^{-5}$的速率发生。
The frontier between Small-scale bipoles and Ephemeral Regions in the solar photosphere: Emergence and Decay of an Intermediate-scale bipole observed with IMaX/SUNRISE
我们报告的光球演化的中等规模（~4毫米的脚点分离）磁双极，从出现到衰变，在安静的太阳在高空间0”.3和时间（33秒）分辨率。这些观测结果是在日出气球太阳观测站第一次科学飞行期间由IMaX成像磁象仪获得的。双极通量含量为6 × 10^17 Mx，代表着一种连接颗粒尺度双极和较小的短暂区域之间的结构。足迹分离的速度为3.5公里s-1，并达到4.5毫米的最大距离之前，该领域溶解。双极的演化是非常动态的：我们发现了双极轴的自行，并在300秒内检测到90°的方位角变化。的整体形态和行为是在协议与先前的分析出现在颗粒尺度的双极结构，但我们也发现了一些相似之处，新兴的通量结构在更大的规模。通量增长率为2.6 x 15 Mx s-1，而平均衰减率小一个数量级。我们在一些细节描述的双极足点，其中包括分解成更小的结构，相互作用与预先存在的领域导致取消，但似乎是占主导地位的一个尚未确定的扩散过程，删除了大部分的通量与指数通量衰减曲线的衰减阶段。与这种衰变相关的扩散常数（8 x 10^2 km^2 s-1）与通量输运模型中用于描述大尺度扩散的数值相似。
基于IMaX/日出数据，我们报告了一种以前未被发现的太阳颗粒化现象。我们发现，在一个非常狭窄的区域分离颗粒和晶间车道的谱线宽度的Fe I 5250.2 A线变得非常小。我们提供了一个解释，这一观察与磁对流模拟的帮助。这些具有极小线宽的区域对应于颗粒流从颗粒中的主要向上流动弯曲到颗粒间通道中的向下流动的地方。我们表明，通过IMaX/日出实现的分辨率和图像稳定性是检测这种有趣现象的重要标志。
Slender Ca II H Fibrils Mapping Magnetic Fields in the Low Solar Chromosphere
在太阳活动区附近的一个密集的细长明亮的纤维森林中，可以看到高质量的窄带Ca II H图像，这些图像来自日出气球搭载的太阳观测站上的SuFI仪器。这些细长的Ca II H纤维（SCF）的取向重叠的磁场配置在低太阳色球层的静磁外推的光球场观测日出/IMAX和SDO/HMI。此外，许多观察到的SCF定性对齐的小尺度循环计算从一个新的反演方法的基础上最佳拟合数值MHD模拟。这些环在安静的区域上以树冠状的拱形结构组织起来，这些拱形结构的高度取决于它们根部附近的场强。
