Nonresonant absorption of shear Alfven waves

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/90GL02047· OSTI ID:5183761

Strauss, H R ^[1]

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1. New York Univ., NY (United States)

Resonant absorption of shear Alfven waves is thought to be a likely candidate to explain heating of the solar corona and acceleration of the solar wind. A difficulty with the theory is that the absorption process is slow. It takes a long time {approximately}S{sup 1/3}{tau}{sub A}, where S >> 1 is the magnetic Reynolds number, and {tau}{sub A} a typical Alfven wave propagation time, for wave fronts to steepen sufficiently for absorption to occur. Moreover, heating occurs in a very thin layer whose width scales as S{sup {minus}1/3}. A faster absorption mechanism is nonresonant absorption by compressional viscosity, in a curved magnetic field. Heating is nonresonant and is not localized to a narrow layer. The effect could be quite important where the solar coronal magnetic field is strongly curved, in the chromosphere. It could also be important on open field lines in the upper corona, where the compressional viscosity is large. It might imply that a significant part of outgoing Alfven waves are absorbed in the corona.

• OSTI ID: 5183761
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 18:1; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
ACCELERATION
ALFVEN WAVES
ATMOSPHERES
BALLOONING INSTABILITY
CHROMOSPHERE
DAMPING
HEATING
HELMHOLTZ INSTABILITY
HYDROMAGNETIC WAVES
INSTABILITY
MAGNETIC FIELDS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
SHEAR
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR CORONA
SOLAR WIND
STELLAR ATMOSPHERES
STELLAR CORONAE
TURBULENCE
VISCOSITY
WAVE PROPAGATION