We investigate possibilities of solar coronal heating by acoustic waves generated not at the photosphere but in the corona , aiming at heating in the mid- to low-latitude corona where the low-speed wind is expected to come from .
Acoustic waves of period \tau \sim 100 s are triggered by chromospheric reconnection , one model of small scale magnetic reconnection events recently proposed by Sturrock .
These waves having a finite amplitude eventually form shocks to shape sawtooth waves ( N-waves ) , and directly heat the surrounding corona by dissipation of their wave energy .
Outward propagation of the N-waves is treated based on the weak shock theory , so that the heating rate can be evaluated consistently with physical properties of the background coronal plasma without setting a dissipation length in an ad hoc manner .
We construct coronal structures from the upper chromosphere to the outside of 1AU for various inputs of the acoustic waves having a range of energy flux of F _ { w, 0 } = ( 1 - 20 ) \times 10 ^ { 5 } erg cm ^ { -2 } s ^ { -1 } and a period of \tau = 60 - 300 s. The heating by the N-wave dissipation effectively works in the inner corona and we find that the waves of F _ { w, 0 } \geq 2 \times 10 ^ { 5 } erg cm ^ { -2 } s ^ { -1 } and \tau \geq 60 s could maintain peak coronal temperature , T _ { max } > 10 ^ { 6 } K. The model could also reproduce the density profile observed in the streamer region .
However , due to its short dissipation length , the location of T _ { max } is closer to the surface than the observation , and the resultant flow velocity of the solar wind is lower than the observed profile of the low-speed wind .
The cooperations with other heating and acceleration sources with the larger dissipation length are inevitable to reproduce the real solar corona .