利用锥模型反演CME三维参数

CME 3D-parameters Inversion by Cone Model

CME会影响近地空间环境,带来地磁扰动,预报其能否到达地球及何时到达地球具有重要的应用意义.受观测能力限制,通常根据CME在太阳附近的日冕仪投影观测信息,利用锥模型拟合得到三维参数,进而以经验预报或代入行星际传播过程模拟,预报CME的对地有效性.在拟合过程中,可以采取不同时刻日冕仪观测数据作为输入,也可以选择是否限定CME发生在耀斑附近进行拟合,这有可能得到截然不同的CME三维参数,从而严重影响CME的传播预报结果.本文选取一个全晕CME事件和一个偏晕CME事件,分析了不同的数据输入和拟合方式带来的CME三维参数拟合结果的变化,评估其对CME传播预报的影响.研究发现,不同的数据源和拟合方式得到的CME三维参数有较大差异,影响了CME对地有效性的预报.后续有必要通过统计分析,评估采用哪些输入数据、哪种拟合方式,对CME对地有效性的预报更准确.

CME can affect the near-earth space environment and cause a geomagnetic disturbance.Therefore,it is of great application significance to predict whether and when it can reach the earth.Due to the limitation of observation ability,3 D-parameters are usually obtained by using cone model fitting according to the coronagraph projection observation information of CME near the sun,and then the effectiveness on earth of CME can be predicted by empirical prediction or interplanetary propagation process simulation.In the process of fitting,coronagraph observation data at different times can be taken as input,or CME can be restricted to occur near flares for fitting,which may result in completely different CME 3 D-parameters,thus seriously affecting CME propagation prediction results.This paper selects a full halo CME event and a partial halo CME event,analyzes the changes of CME 3 D parameter fitting results caused by different data input and fitting methods,and evaluates their impact on CME propagation prediction.The study found that the 3 D-parameters of CME obtained by different data sources and fitting methods were significantly different,which affected the prediction of the ground validity of CME.In the future,it is necessary to evaluate the input data adopted and the fitting method,so as to predict the effects on earth of CME more accurately.