On the Heating of the Solar Corona and the Acceleration of the Low-Speed Solar Wind by Acoustic Waves Generated in Corona

Abstract

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 ~ 100s 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 = 60-300s. The heating by the N-wave dissipation effectively works in the inner corona and we find that the waves of F_{w,0} >= 2 times 10^5 erg cm^{-2} s^{-1} and tau >= 60s 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.

32 pages, including 10 figures, ApJ vol.578, in press (v2 : corrections of mis-typed 'fmax' values in the tables 1 & 2)

References in corpus (1)

• Origins of the slow and the ubiquitous fast solar wind

Cited by in corpus (19)

• Making the corona and the fast solar wind: a self-consistent simulation for the low-frequency Alfven waves from photosphere to 0.3AU
• Investigating Mercury's Environment with the Two-Spacecraft BepiColombo Mission
• Extended MHD modeling of the steady solar corona and the solar wind
• Forecasting Solar Wind Speeds
• Connecting the Sun and the Solar Wind: The Self-consistent Transition of Heating Mechanisms
• Structured Red Giant Winds with Magnetized Hot Bubbles and the Corona/Cool Wind Dividing Line
• Generation of Alfven Waves by Magnetic Reconnection
• Coronal Heating and Acceleration of the High/Low-Speed Solar Wind by Fast/Slow MHD Shock Trains
• On Heating of Cluster Cooling Flows by Sound Waves
• Stellar Winds and Coronae of Low-mass Pop. II/III Stars
• Tsunamis in Galaxy Clusters: Heating of Cool Cores by Acoustic Waves
• Self-consistent Simulations of Alfven Wave Driven Winds from the Sun and Stars
• Collisionless Damping of Fast MHD Waves in Magneto-rotational Winds
• Quiet Sun X-rays as Signature for New Particles
• Role of Longitudinal Waves in Alfvén-wave-driven Solar Wind
• The Origin of Ripples in Cool Cores of Galaxy Clusters: Heating by MHD Waves?
• A new model for heating of Solar North Polar Coronal Hole
• The Difficulty of the Heating of Cluster Cooling Flows by Sound Waves and Weak Shocks
• Magnetic field generation by charge exchange in a supernova remnant in the early universe