Hit or Miss, Arrival Time, and $B_z$ Orientation Predictions of BATS-R-US CME Simulations at 1 AU

Abstract

Using a refined setup process, we simulated the propagation of six observed Coronal Mass Ejections (CMEs) with the 2012 Block-Adaptive-Tree-Solarwind-Roe-Upwind-Scheme (BATS-R-US) code from the Sun to the Earth or STEREO A and compared the outputs with observations. A linear relation between the average CME speed below 6 solar radii and the flux rope current is demonstrated and used to tune the simulations. The simulations correctly predict if and when an observable CME shock reaches one astronomical unit (AU). The arrival time predictions of the CME shocks at 1 AU have an accuracy of 0.9 $\pm$ 1.9 hours. The simulated initial CME speeds and average accelerations are close to the model and data of Gopalswamy et al., 2000. The approach shows promise for predicting the sense of the predominant shock-associated change in the magnetic field component $B_z$. However, the magnetic fields and plasma conditions in the solar wind and CME are not predicted well quantitatively.