Why (And How) We Should Observe The Dynamic Middle Corona

Abstract:

Although the solar corona is the primary driver of almost all plasma dynamics throughout the solar system, the precise nature of the connection between the corona and heliosphere remains poorly understood. Parker Solar Probe observations from 0.3 AU have revealed a highly structured environment shaped by flows and ejecta interacting with the corona’s complex magnetic field. Critically, significant physical transitions in the middle corona — i.e. from closed to open magnetic field and, in some locations, low to high plasma beta — govern the overall connectivity between the inner corona and heliosphere. However, observations of this region remain scarce, and completely connecting PSP observations to the low corona remains a challenge. New approaches to observations, particularly in the EUV, can fully reveal this region, its dynamics, and connectivity to the outer corona, opening the door to resolving a decades-old mystery about the relationship between the solar wind, solar eruptions, and the low corona. In this talk we demonstrate how new observations will lead to the development of coherent understanding of the corona and heliosphere as a single system in a region where deep connections have previously only been inferred. We discuss the variability of the middle corona we see in these observations, and what this variability reveals about the importance of the evolving Sun’s influence on the heliosphere as a whole.