Exploring the Magnetic Connection Between the Photosphere and Low Corona

Team Chair: Alphonse Sterling
Next Team Meeting:
Team-Maintained Web Site:
Team Reports: Team Progress Report: Year 1, December 2009
Team Members:

Target Description: Many LWS models of the corona and heliosphere depend on boundary conditions at the coronal base (the lowest altitude where the plasma beta is small), yet observations of the magnetic field come mostly from the photosphere below. It is therefore vital to understand how the magnetic field maps from the photosphere, through the chromosphere and transition region, and into the corona. This region of the atmosphere is also important for other reasons. For example, much of the UV radiation that drives the ionosphere/thermosphere system originates in the chromosphere and is determined by the chromospheric heating and structure.

It has also been proposed that the waves that accelerate and heat the solar wind may be generated by magnetic reconnection events in this region. A host of new observational sources of the solar atmosphere (including high resolution and high cadence photospheric vector magnetograms) are coming on line, which promise to promote real progress in the predictive qualities of these LWS coronal and heliospheric models. To realize this progress, we need to understand the implications of these new observations for the structure and dynamic behavior of the intervening chromosphere and transition region. Therefore we invite proposals with the goal of improving our ability to model this critical region with the explicit long-term goal of improving the predictive capabilities of coronal and heliospheric models, and the ionospheric/thermospheric models which depend upon solar UV emissions.

Goals and measures of success: The measures of success for this topic are the impact of the science advances made by the team in improving the predictive capabilities of our current models.

Types of solicited investigations: This group will include theoreticians, numerical modelers, and observers. Proposals which address this topic should use high resolution magnetograms directly or couple with other team models which do so. Examples of investigations which are encouraged include:
• Determine improved boundary conditions at the inner boundary of coronal models;
• Through modeling, provide a physical interpretation of UV data and images; or
• Increase understanding of the source of chromospherically generated waves which heat and accelerate the solar wind.