Linking Magnetic Complexity to Coronal Heating and Solar Wind Structure

Abstract:

The Sun’s magnetic field plays a pivotal role in the processes that heat the corona and accelerate the solar wind. In this talk we describe our recent effort to link complexity in the surface magnetic field, such as small-scale flux elements and parasitic polarities, to structure and plasma properties in the low corona and solar wind. Born out of our prediction effort for the July 2, 2019 total solar eclipse, we conducted three global coronal magnetohydrodynamic (MHD) simulations that included increasingly finer scale detail in the magnetic boundary condition at the surface. The final simulation is the largest global coronal MHD simulation we have ever attempted. Each simulation used the same parameterization of the MAS-WTD model, which incorporates essential aspects of coronal energy transport and Alfvénic turbulence through a Wave-Turbulence-Driven (WTD) approach. Although the macroscopic properties of each solution remain essentially the same, high-resolution structures emerge in the low coronal heating rate and plasma properties, essentially at the scale limit of the boundary conditions. Focusing on the large northern polar hole, we show how small variations in field mappings and flux-tube properties near the surface (r<1.05 Rs) naturally lead to pockets of structure and variation at much larger distances throughout the open solar wind region (r>3 Rs). The finding that complexity in the photospheric magnetic field may leave an indelible imprint in the corona and solar wind has important implications for our understanding of both coronal heating and intermediate scale plasma variations in the wind.