Transverse energy injection scales at the base of the solar corona

Alfvén wave turbulence models are the foundation of many investigations into the winds and EUV/X-ray emission from cool, solar-like stars. The models are used to estimate mass loss rates, magnetic spin down and exoplanet habitability. However, the models currently rely on ad-hoc estimates of critical parameters. One such parameter is the perpendicular correlation length, L_⊥ (the energy injection length scale), whose value has significant influence over the turbulent heating and mass loss rates. Using the Coronal Multi-channel Polarimeter, a ground based corona-graph, we provide the first measurements of the correlation length of Alfvénic waves at the base of the corona. Our analysis shows the values are broadly homogeneous through the corona and have a distribution sharply peaked around 7.6 - 9.3 Mm. The measured correlation length is comparable to the expected scales associated with supergranulation. The results also suggest a discrepancy between the coronal values of L_⊥, theoretical transport models for the evolution of L_⊥ with distance from the Sun, and previous estimates of L_⊥ beyond the Alfvén critical zone. We suggest a thesis as to the missing physics.