Assessment and Validation of MHD Models for the Solar Corona and Inner Heliosphere

We describe the status of a model assessment and validation project for testing MHD codes that simulate the solar corona and inner heliosphere. The goal of the project is to test MHD codes by applying firm empirical constraints to their boundary conditions in the corona and at 1 AU. The project has produced a database of coronal and solar wind observations from SOHO, ACE, Wind, and Ulysses. In addition to the database, software tools for comparing these data sets to the outputs for the MHD model codes under test will be demonstrated. The first step is to take the plasma parameters that are produced from the model codes and apply forward modeling to simulate the coronal observations of emission lines (H I Lyman alpha and O VI 103.2 nm). In situ solar wind data are used not only to provide benchmarks near 1 AU but also to provide coronal constraints for the coronal source regions of the solar wind. Future stages will involve making more direct comparisons of the plasma properties predicted from the model codes through the use of empirical coronal and solar wind models. We also describe a set of metrics that are used for making comparisons between the model code outputs and the empirical data. This work is supported by NASA under Grants NNX07AB98G to the Smithsonian Astrophysical Observatory and NNX07AB99G to the University of Michigan.