论文标题
2012年7月12日的冠状质量弹出的合奏模拟,其恒定转向磁通绳模型
Ensemble simulations of the 12 July 2012 Coronal Mass Ejection with the Constant Turn Flux Rope Model
论文作者
论文摘要
冠状质量弹出(CMES)的基于通量的磁力流动力模型(CMES)是预测CME到达时间和地球磁场的有前途的工具。在这项工作中,我们引入了一个恒定的磁通绳模型,并使用它模拟了内层中的2012年7月12日16:48 CME。我们使用刻度的圆柱形壳(GCS)模型和在爆发后拱门中的重新连接通量来限制此CME的初始参数。我们正确地重现了地球中CME的所有磁场组件,到达时间误差约为1小时。我们通过比较在多个研究和目录中报道的56个CME的GCS参数,进一步估算GCS配件中的平均主观不确定性。我们确定CME纬度,经度,倾斜和速度的GC估计值分别为5.74度,11.23度,24.71度和11.4%。使用这些,我们为2012年7月12日CME创建了77个合奏成员。我们发现55%的集合成员正确地重现了地球磁场成分的符号。我们还确定,GCS拟合中的不确定性可以将CME到达时间预测窗口扩大到2012年7月12日CME的12小时。在研究单个GCS参数中不确定性引入的预测准确性时,我们得出的结论是,半角度和纵横比对2012年7月12日至7月12日CME的预测磁场的影响很小,而经度和倾斜的不确定性可以在地球预测的磁场中引入相对大的磁场。
Flux-rope-based magnetohydrodynamic modeling of coronal mass ejections (CMEs) is a promising tool for the prediction of the CME arrival time and magnetic field at Earth. In this work, we introduce a constant-turn flux rope model and use it to simulate the 12-July-2012 16:48 CME in the inner heliosphere. We constrain the initial parameters of this CME using the graduated cylindrical shell (GCS) model and the reconnected flux in post-eruption arcades. We correctly reproduce all the magnetic field components of the CME at Earth, with an arrival time error of approximately 1 hour. We further estimate the average subjective uncertainties in the GCS fittings, by comparing the GCS parameters of 56 CMEs reported in multiple studies and catalogs. We determined that the GCS estimates of the CME latitude, longitude, tilt, and speed have average uncertainties of 5.74 degrees, 11.23 degrees, 24.71 degrees, and 11.4% respectively. Using these, we have created 77 ensemble members for the 12-July-2012 CME. We found that 55% of our ensemble members correctly reproduce the sign of the magnetic field components at Earth. We also determined that the uncertainties in GCS fitting can widen the CME arrival time prediction window to about 12 hours for the 12-July-2012 CME. On investigating the forecast accuracy introduced by the uncertainties in individual GCS parameters, we conclude that the half-angle and aspect ratio have little impact on the predicted magnetic field of the 12-July-2012 CME, whereas the uncertainties in longitude and tilt can introduce a relatively large spread in the magnetic field predicted at Earth.