On the Sources and Sizes of Uncertainty in Predicting the Arrival Time of Interplanetary Coronal Mass Ejections Using Global MHD Models

Accurate predictions of the properties interplanetary coronal mass ejection (ICME)-driven disturbances are a key objective for space weather forecasts. The ICME's time arrival (ToA) at Earth is an important parameter, and one that amenable to variety modeling approaches. Previous studies suggest best models can predict within absolute uncertainty 10–15 h. Here, we investigate main sources in predicting CME's ToA Earth. These be broken into two categories: (a) initial ejecta, including its speed, mass, direction propagation (b) ambient solar wind which it propagates. To estimate relative contribution uncertainties, construct set numerical experiments cone-model CMEs, where vary inner radial boundary. Additionally, build ensemble 12 solutions using realizations from ADAPT model. We find each component chain contributes between ±2.5 ±7 h ToA. Importantly, different synoptic produce largest uncertainties. This suggests estimates will continue plagued with intrinsic uncertainties ±10 until tighter constraints found these boundary conditions. Our results there clear benefits focused investigations aimed reducing CME direction, input magnetic fields.