MHD modeling of solar wind background and flux-rope CMEs

Authors: Nishtha Sachdeva, Gabor Toth, Chip Manchester, Bart van der Holst, Zhenguang Huang, Aniket Jivani, Hongfang Chen

The Alfven Wave Solar atmosphere Model (AWSoM) is a 3D extended-MHD solar corona model within the Space Weather Modeling Framework (SWMF), used to model the solar wind in the solar corona and the inner heliosphere. AWSoM, in conjunction with the Eruptive Event Generator using Gibson & Low (EEGGL) can be used to model flux-rope CMEs from the Sun to the Earth. EEGGL is used to determine the initial parameters of a flux-rope based on the Gibson & Low configuration. It uses an automated tool that requires only the selection of the active region where the CME erupts from and the CME speed to determine the geometrical parameters as well as flux-rope size, orientation, and field strength. The flux-rope is then launched into a solar-wind background modeled using AWSoM and validated against the observations. In this work, we describe the latest developments made to the EEGGL tool used for CME modeling with AWSoM.  We use an ensemble of solar wind backgrounds to determine the best solar wind plasma environments into which CMEs can be launched. Using EEGGL parameters as the base, we vary the flux-rope parameters within a fixed range to do an ensemble of simulations of the CMEs and compare the simulated results with coronagraph observations near the Sun as well as 1 AU observations of solar wind plasma. The ensemble modeling is a step forward towards improving the accuracy of the EEGGL tool and uncertainty quantification of CME modeling.