This paper presents the results of the analysis of 3D simulations of solar magneto-convection that include the joint action of the ambipolar diffusion and the Hall effect. Three simulation-runs are compared: one including both ambipolar diffusion and Hall effect; one including only ambipolar diffusion; and one without any of these two effects. The magnetic field is amplified from initial field to saturation level by the action of turbulent local dynamo. In each of these cases, we study 2 hours of simulated solar time after the local dynamo reaches the saturation regime. We analyze the power spectra of vorticity, of magnetic field fluctuations and of the different components of the magnetic Poynting flux responsible for the transport of vertical or horizontal perturbations. Our preliminary results show that the ambipolar diffusion produces a strong reduction of vorticity in the upper chromospheric layers and that it dissipates the vortical perturbations converting them into thermal energy. The Hall effect acts in the opposite way, strongly enhancing the vorticity. When the Hall effect is included, the magnetic field in the simulations becomes, on average, more vertical and long-lived flux tube-like structures are produced. We trace a single magnetic structure to study its evolution pattern and the magnetic field intensification, and their possible relation to the Hall effect.
Two-dimensional Radiative Magnetohydrodynamic Simulations of Partial Ionization in the Chromosphere. II. Dynamics and Energetics of the Low Solar Atmosphere
Comparison of two- and three-dimensional compressible convection in a pre-main sequence star
扩展我们最近的研究二维恒星对流到3D，我们比较三维流体动力学模拟相同的设置了二维模拟，一个现实的前主序星。我们比较了与对流有关的统计量，包括：平均速度，涡度，局部拟能和对流区下的穿透深度。这些统计数据是在恒星对流区的静止、稳态可压缩对流过程中产生的。我们的模拟与MUSIC代码证实了共同的结果，即恒星对流的二维模拟有一个更高的幅度的平均速度比三维模拟。边界条件和球壳的范围可以影响对流速度的大小和变化。2D和3D速度之间的差异取决于这些背景点;在我们的模拟中，这可能会产生与模拟维度导致的差异一样大的影响。然而，在我们的二维和三维模拟中，对流边界附近的径向速度是相当的。平均局部拟能的流量是较低的二维模拟比三维模拟，表明不同的形状和结构的三维恒星对流。我们使用我们最近研究中提出的模型（Pratt et al. 2017）对对流区以下的对流渗透深度进行了统计分析。在这里，我们分析了三维模拟中的对流渗透，并将结果与相同设置的2D模拟进行比较。在3D中，穿透深度与从2D模拟计算的穿透深度一样大。
The Interplay of Magnetic Fields, Turbulence and Vorticity in Core-Collapse Supernovae
North Carolina State University（北卡罗来纳州立大学）；Clausthal University of Technology（克劳塔尔工业大学）；Oak Ridge National Laboratory（橡树岭国家实验室）；University of Basel（巴塞尔大学）
