Validation of the Alfv\'{e}n Wave Solar atmosphere Model (AWSoM) with Observations from the Low Corona to 1 AU

TL;DR

This study validates the AWSoM model against diverse observations from the solar corona to 1 AU, demonstrating its accuracy in simulating solar wind and coronal conditions during solar minimum.

Contribution

The paper presents a comprehensive validation of the latest AWSoM model against multi-instrument observations, confirming its effectiveness in modeling the solar atmosphere and heliosphere.

Findings

Model accurately reproduces solar wind speeds from the corona to 1 AU.

AWSoM captures the fast solar wind in polar regions.

Good agreement with in-situ measurements of solar wind near Earth.

Abstract

We perform a validation study of the latest version of the Alfv\'{e}n Wave Solar atmosphere Model (AWSoM) within the Space Weather Modeling Framework (SWMF). To do so, we compare the simulation results of the model with a comprehensive suite of observations for Carrington rotations representative of the solar minimum conditions extending from the solar corona to the heliosphere up to the Earth. In the low corona ($r < 1.25$ \Rs), we compare with EUV images from both STEREO-A/EUVI and SDO/AIA and to three-dimensional (3-D) tomographic reconstructions of the electron temperature and density based on these same data. We also compare the model to tomographic reconstructions of the electron density from SOHO/LASCO observations ($2.55 < r < 6.0$\Rs). In the heliosphere, we compare model predictions of solar wind speed with velocity reconstructions from InterPlanetary Scintillation (IPS) observations. For comparison with observations near the Earth, we use OMNI data. Our results show that the improved AWSoM model performs well in quantitative agreement with the observations between the inner corona and 1 AU. The model now reproduces the fast solar wind speed in the polar regions. Near the Earth, our model shows good agreement with observations of solar wind velocity, proton temperature and density. AWSoM offers an extensive application to study the solar corona and larger heliosphere in concert with current and future solar missions as well as being well suited for space weather predictions.