标题： 模拟非径向传播的日冕物质抛射并预测它们到达地球的时间 显示英文标题

标题： Modelling non-radially propagating coronal mass ejections and forecasting the time of their arrival at Earth

摘要： 我们研究了2020年12月7日和2021年10月28日观测到的两个太阳爆发事件。这两个事件都与全晕日冕物质抛射和耀斑有关。选择这些事件是因为它们在低日冕中表现出强烈的非径向传播方向，且其主要传播方向并未完全与日地连线对齐。这一特性使它们适合我们的研究，该研究旨在检查低日冕中的非径向传播方向如何影响日冕物质抛射到达地球的时间。我们使用日冕仪观测数据重建了日冕物质抛射，并用EUHFORIA和日冕物质抛射的圆锥模型对其进行模拟。为了比较不同方法获得的日冕物质抛射到达地球时间预测的准确性，我们还使用所谓的II型爆发，即相关激波的无线电特征，来确定日冕物质抛射驱动激波的速度，并预测它们到达地球的时间。我们还使用二维日冕物质抛射速度估计了日冕物质抛射到达地球的时间。我们的结果表明，当使用二维日冕物质抛射速度时，估计的日冕物质抛射到达地球时间的准确性最低。II型无线电爆发的速度提供了更好的但仍然不够准确的结果。将从GCS拟合中在逐渐增加的高度上获得的日冕物质抛射参数作为输入用于EUHFORIA，使得模拟的日冕物质抛射和激波到达时间的准确性显著提高。对于第一个事件，Δt的变化从14小时减少到10分钟，对于第二个事件，Δt的变化从12小时减少到30分钟。这种改进表明，当我们增加GCS重建的高度时，我们考虑了所研究日冕物质抛射传播方向的变化，这使我们能够准确模拟日冕物质抛射侧面在地球的遭遇。 我们的结果表明，在建模日冕物质抛射并估计其到达地球的时间时，日冕物质抛射在低日冕中的传播方向变化具有重要意义。 显示英文摘要

摘要： We present the study of two solar eruptive events observed on December 7 2020 and October 28 2021.Both events were associated with full halo CMEs and flares.These events were chosen because they show a strong non-radial direction of propagation in the low corona and their main propagation direction is not fully aligned with the Sun-Earth line.This characteristic makes them suitable for our study, which aims to inspect how the non-radial direction of propagation in the low corona affects the time of CMEs' arrival at Earth.We reconstructed the CMEs using coronagraph observations and modelled them with EUHFORIA and the cone model for CMEs.To compare the accuracy of forecasting the CME arrival time at Earth obtained from different methods, we also used so-called typeII bursts, radio signatures of associated shocks, to find the velocities of the CME-driven shocks and forecast the time of their arrival at Earth.We also estimated the CME arrival time using the 2D CME velocity.Our results show that the lowest accuracy of estimated CME Earth arrival times is found when the 2D CME velocity is used.The velocity of the typeII radio bursts provides better, but still not very accurate, results.Employing, as an input to EUHFORIA, the CME parameters obtained from the GCS fittings at consequently increasing heights, results in a strongly improved accuracy of the modelled CME and shock arrival time Delta t changes from 14h to 10min for the first event, and from 12h to 30min for the second one.This improvement shows that when we increased the heights of the GCS reconstruction we accounted for the change in the propagation direction of the studied CMEs, which allowed us to accurately model the CME flank encounter at Earth. Our results show the great importance of the change in the direction of propagation of the CME in the low corona when modelling CMEs and estimating the time of their arrival at Earth.