Modeling and validating the solar wind using the Alfven Wave Solar atmosphere Model

To reliably predict the space weather due to the impact of solar transients, it is imperative to accurately model the solar wind background into which these solar transients propagate. The Alfven Wave Solar atmosphere Model (AWSoM) within the Space Weather Modeling Framework (SWMF) is a physics-based 3D extended MHD model to simulate the solar wind conditions. AWSoM includes radiative cooling, heat conduction and turbulence due to non-linear interaction between forward-propagating and reflected waves. It is driven by observations of the photospheric magnetic field which provide the magnetic field at the inner boundary for the model. We use data-products from different sources like, GONG and HMI along with ADAPT magnetograms to investigate how the model results vary based on the initial driving condition. Observation inaccuracies in the magnetic field measurements may lead to uncertainties in the modeling of the plasma environment into which CMEs propagate. These modeling efforts are validated by both in-situ and remote observations including EUV observations in the low corona from STEREO-A/B and SDO-AIA as well as plasma parameters at L1 from the OMNI database.

AWSoM results are also dependent on a few free parameters that vary depending on the phase of the solar cycle. For example, during periods of higher solar activity the Poynting flux parameter at the inner boundary needs to be adjusted to match the observations well to model the solar wind background and provide correct initial conditions for CME propagation. This work is in preparation for simulating CMEs launched from the Sun and propagating into correct solar wind background to achieve accurate and reliable space weather modeling and prediction.