论文标题
使用3DCORE和近似贝叶斯计算分析冠状质量弹出通量绳索签名
Analysis of coronal mass ejection flux rope signatures using 3DCORE and approximate Bayesian Computation
论文作者
论文摘要
我们提出了3D冠状绳弹出(3DCORE)技术的重大更新,该技术与近似贝叶斯计算(ABC)算法结合使用冠状质量弹出通量绳,该算法用于拟合模型以适合现场磁场测量值。该模型假设具有经验动机的类似圆环的通量绳结构,该结构在地球球内扩展自相似,受到与太阳风环境的简化相互作用的影响,并沿着嵌入式的分析磁场携带。改进的3DCORE实现使我们能够生成非常大的集合模拟,然后使用ABC顺序蒙特卡洛(SMC)算法来找到全局最佳拟合模型参数。在对磁场测量值的不确定性的一些基本假设下,该算法的使用使我们能够进一步仅使用单个原位观察结果对模型参数的不确定性产生估计。我们将模型应用于合成生成的测量结果,以证明我们实施对拟合程序的有效性。我们还在模型范围内进行了简短的分析,该分析是对帕克太阳能探针(PSP)捕获的事件,该事件在2018年11月12日的第一次太阳飞行后不久,在0.25 au。提出的工具集也很容易扩展到对多个航天器捕获的事件的分析,因此将促进未来的多点研究。
We present a major update to the 3D coronal rope ejection (3DCORE) technique for modeling coronal mass ejection flux ropes in conjunction with an Approximate Bayesian Computation (ABC) algorithm that is used for fitting the model to in situ magnetic field measurements. The model assumes an empirically motivated torus-like flux rope structure that expands self-similarly within the heliosphere, is influenced by a simplified interaction with the solar wind environment, and carries along an embedded analytical magnetic field. The improved 3DCORE implementation allows us to generate extremely large ensemble simulations which we then use to find global best-fit model parameters using an ABC sequential Monte Carlo (SMC) algorithm. The usage of this algorithm, under some basic assumptions on the uncertainty of the magnetic field measurements, allows us to furthermore generate estimates on the uncertainty of model parameters using only a single in situ observation. We apply our model to synthetically generated measurements to prove the validity of our implementation for the fitting procedure. We also present a brief analysis, within the scope of our model, of an event captured by Parker Solar Probe (PSP) shortly after its first fly-by of the Sun on 2018 November 12 at 0.25 AU. The presented toolset is also easily extendable to the analysis of events captured by multiple spacecraft and will therefore facilitate future multi-point studies.