MHD‐driven kinetic dissipation in the solar wind and corona
Leamon, R. J., Matthaeus, W. H., Smith, C. W., Zank, G. P., Mullan, D. J., & Oughton, S. (2000). MHDâ driven Kinetic Dissipation in the Solar Wind and Corona. The Astrophysical Journal, 537(2), 1054-1062
Permanent Research Commons link: https://hdl.handle.net/10289/8609
Mechanisms for the deposition of heat in the lower coronal plasma are discussed, emphasizing recent attempts to reconcile the fluid and kinetic perspectives. Structures at magnetohydrodynamic (MHD) scales may drive a nonlinear cascade, preferentially exciting high perpendicular wavenumber fluctuations. Relevant dissipative kinetic processes must be identified that can absorb the associated energy flux. The relationship between the MHD cascade and direct cyclotron absorption, including cyclotron sweep, is discussed. We conclude that for coronal and solar wind parameters the perpendicular cascade cannot be neglected and may be more rapid than cyclotron sweep. Solar wind observational evidence suggests the relevance of the ion inertial scale, which is associated with current sheet thickness during reconnection. We conclude that a significant fraction of dissipation in the corona and solar wind likely proceeds through a perpendicular cascade and small-scale reconnection, coupled to kinetic processes that act at oblique wavevectors.
University of Chicago Press
© 2000 the American Astronomical Society.