Coronal Heating Distribution Due to Low‐Frequency, Wave‐driven Turbulence

The heating of the lower solar corona is examined using numerical simulationsand theoretical models of magnetohydrodynamic turbulence in open magneticregions. A turbulent energy cascade to small length scales perpendicular to themean magnetic field can be sustained by driving with low-frequency Alfven wavesreflected from mean density and magnetic field gradients. This mechanismdeposits energy efficiently in the lower corona, and we show that the spatialdistribution of the heating is determined by the mean density through theAlfven speed profile. This provides a robust heating mechanism that can explainobserved high coronal temperatures and accounts for the significant heating(per unit volume) distribution below two solar radius needed in models of theorigin of the solar wind. The obtained heating per unit mass on the other handis much more extended indicating that the heating on a per particle basispersists throughout all the lower coronal region considered here.Comment: 19 pages, 5 figures. Accepted for publication in Ap