Quantifying the uncertainty in CME kinematics derived from geometric modelling of Heliospheric Imager data
Quantifying the uncertainty in CME kinematics derived from geometric modelling of Heliospheric Imager data
复制标题
量化由日光层成像仪数据的几何建模得出的日冕物质抛射运动学的不确定性
DOI：
10.1002/essoar.10507552.1
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Barnard L
中科院分区：
文献类型：
--
作者：
Barnard L
日冕物质抛射（CME）的几何模拟是一种广泛使用的评估其运动学演化的工具。此外，基于几何建模的技术，如ELEvoHI，正在发展成为空间气象预测的预测工具。这些模型假设太阳风结构不影响日冕物质抛射的演变，这是一个不可量化的不确定性来源。我们使用了大量的圆锥CME模拟与HUXt太阳风模型，以量化的几何建模和ELEvoHI CME到达时间的太阳风结构引入的不确定性的规模。我们制作了一个模拟数据库，代表了平均，快速和极端的CME场景，每个场景都独立地通过100个不同的太阳风环境传播。合成日光层成像仪观察这些模拟，然后使用一系列的几何模型来估计日冕物质抛射的运动学。几何建模的误差取决于观察者的位置，但似乎不依赖于CME场景。一般来说，几何模型偏向于预测大于真实值的CME顶点距离。对于这些CME场景，对于L5区域中的观察者，几何建模误差被最小化。此外，几何建模误差随着CME路径中太阳风结构的水平而增加。对于L5区域的观测者，ELEvoHI到达时间误差最小，平均、快速和极端CME场景的平均绝对到达时间误差分别为8.2 ± 1.2 h、8.3 ± 1.0 h和5.8 ± 0.9 h。
Geometric modeling of Coronal Mass Ejections (CMEs) is a widely used tool for assessing their kinematic evolution. Furthermore, techniques based on geometric modeling, such as ELEvoHI, are being developed into forecast tools for space weather prediction. These models assume that solar wind structure does not affect the evolution of the CME, which is an unquantified source of uncertainty. We use a large number of Cone CME simulations with the HUXt solar wind model to quantify the scale of uncertainty introduced into geometric modeling and the ELEvoHI CME arrival times by solar wind structure. We produce a database of simulations, representing an average, a fast, and an extreme CME scenario, each independently propagating through 100 different ambient solar wind environments. Synthetic heliospheric imager observations of these simulations are then used with a range of geometric models to estimate the CME kinematics. The errors of geometric modeling depend on the location of the observer, but do not seem to depend on the CME scenario. In general, geometric models are biased towards predicting CME apex distances that are larger than the true value. For these CME scenarios, geometric modeling errors are minimised for an observer in the L5 region. Furthermore, geometric modeling errors increase with the level of solar wind structure in the path of the CME. The ELEvoHI arrival time errors are minimised for an observer in the L5 region, with mean absolute arrival time errors of 8.2 ± 1.2 h, 8.3 ± 1.0 h, and 5.8 ± 0.9 h for the average, fast, and extreme CME scenarios.