A Method for the Determination of 3-D Velocity Fields of Disappearing Solar Filaments
A Method for the Determination of 3-D Velocity Fields of Disappearing Solar Filaments
复制标题
确定消失太阳细丝 3-D 速度场的方法
DOI：
10.1093/pasj/55.2.503
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发表时间：
2003
影响因子：
2.3
通讯作者：
H. Kurokawa
中科院分区：
文献类型：
--
作者：
T. Morimoto;H. Kurokawa
为了确定太阳圆盘上消失的暗条的三维速度场，对它们的三维速度场进行了广泛的研究。将Beckers的云模式应用于日田天文台耀斑监测望远镜在Hα线中心和Hα±0.8u A观测到的5个分贝事件，发展了一种求取分贝的完整三维速度场的方法。视线速度是(I)通过计算灯丝的H-α线轮廓得到的，(Ii)通过测量最符合观测到的灯丝对比度的时间变化的多普勒频移来获得。通过在连续的图像上跟踪内部结构的运动来获得切向速度。在该方法中，对仪器的有效滤光片带宽、杂散光和多普勒增亮效应进行了校正。我们还讨论了细丝等离子体在激活过程中的本征变化引起的速度误差，背景色球强度的波动，以及用不同形式的扩散函数来估计杂散光。强调指出，用我们的方法计算消光灯丝的三维矢量轨迹，可以提高空间天气预报的质量，具有更好的确定性。
The 3-D velocity fields of disappearing filaments (Disparition Brusques: DBs) on the solar disk were extensively studied in order to determine their 3-D velocity fields. Applying Beckers’ cloud model to 5 DB events observed in the Hα line center and Hα ±0.8 u A with the Flare Monitoring Telescope (FMT) at Hida Observatory, we developed a method to derive the complete 3-D velocity field of DBs. The line-of-sight velocity is obtained (i) by calculating the Hα line profile of the filament, and (ii) by measuring the Doppler shift which best fits to the observed temporal variations of contrasts of the filament. The tangential velocity is obtained by tracing the motions of the internal structures on the successive images. In this method, corrections for the effective filter bandwidths of the instrument, stray lights, and Doppler brightening effect are performed. We also discuss the velocity errors which arise from the intrinsic variations of the filament plasma during its activation, the fluctuations in intensities of the background chromosphere, and the choice of different forms of the spread function for estimating the stray light. It is emphasized that the calculation of three-dimensional vector trajectories of a disappearing filament with our method can enhance the quality of a space weather forecast with better certainty.