报告题目：Simulating the Formation and Evolution of Solar Prominences

　　报 告 人：夏莼 博士（比利时鲁汶大学）

　　摘    要：The physical mechanism responsible for the formation and the mass cycling of solar prominences has been uncertain for decades, because of the difficulty of knowing the three-dimensional (3D) magnetic field hosting prominences and the mass supply from chromosphere to prominences. Here we report comprehensive 3D simulations which demonstrate that the chromospheric evaporation and the coronal condensation in a magnetic flux rope lead to the formation of a quiescent prominence with complex internal fluid dynamics. First, we simulate the formation of a stable magnetic flux rope in the corona starting from a sheared magnetic bipolar arcade driven by shearing and converging flows at the bottom, using isothermal magnetohydrodynamics (MHD) modeling including gravity. Second, we fill the magnetic flux rope with hydrostatic plasma from chromosphere to corona and simulate a quiet sun in an equilibrium using full thermodynamic MHD with anisotropic thermal conduction, optically thin radiative losses, and parameterized heating. Then, we add extra strong heating localized in two circular regions covering chromospheric foot points of the flux rope. As the plasma is evaporated into corona, the lower part of the flux rope evolve into thermally unstable situation due to dominative radiative losses, where multiple blobs and threads of condensations form and move continuously mainly along local magnetic field. Some of the condensations fall down to chromosphere without support of magnetic dips near the foot region of the flux rope. Others linger in magnetic dips and descend slowly. Synthetic images of Solar Dynamics Observatory views with the Atmospheric Imaging Assembly shows many properties of quiescent prominences from real observations, such as, dynamics dark threads under elliptical coronal cavity.

　　时间及地点：6月25日（周四）下午2:30,202会议室

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