TY - JOUR
T1 - Characteristics of magnetohydrodynamic waves in Harris-type current sheet with guide magnetic field By
AU - Lee, K. W.
AU - Hau, L. N.
PY - 2008/12/1
Y1 - 2008/12/1
N2 - An overview is presented of the characteristics of hydromagnetic waves propagating in Harris-type current sheet with magnetic field of Bx(z) × ̌ and an embedded guide By component based on the ideal magnetohydrodynamic (MHD) model. The wave equations are expressed in the (k∥, k, z) coordinates, and singularities are identified for general cases of ky≠0 and By ≠ 0, where k ∥ and k are the components of the wave vector parallel and perpendicular to the local magnetic field, respectively, and the inhomogeneity is in the z direction. The presence of By may lead to the rotation of the magnetic field relative to the wave vector so that a singular layer with k = 0 surrounded by a neighboring region of k ≠ 0 may exist. This result is in contrast with the Case of By = 0 for which Alfvén or field-line resonance associated with the mathematical singularity tends to occur for k ≠= 0 and ω = k∥ CA, where C A is the Alfvén speed. The possibility for MHD waves with frequency ofω = k∥ CA to propagate through the inhomogeneous layer with By ≠ 0 is analyzed, and numerical solutions for discrete eigenmodes with various free parameter values are presented.
AB - An overview is presented of the characteristics of hydromagnetic waves propagating in Harris-type current sheet with magnetic field of Bx(z) × ̌ and an embedded guide By component based on the ideal magnetohydrodynamic (MHD) model. The wave equations are expressed in the (k∥, k, z) coordinates, and singularities are identified for general cases of ky≠0 and By ≠ 0, where k ∥ and k are the components of the wave vector parallel and perpendicular to the local magnetic field, respectively, and the inhomogeneity is in the z direction. The presence of By may lead to the rotation of the magnetic field relative to the wave vector so that a singular layer with k = 0 surrounded by a neighboring region of k ≠ 0 may exist. This result is in contrast with the Case of By = 0 for which Alfvén or field-line resonance associated with the mathematical singularity tends to occur for k ≠= 0 and ω = k∥ CA, where C A is the Alfvén speed. The possibility for MHD waves with frequency ofω = k∥ CA to propagate through the inhomogeneous layer with By ≠ 0 is analyzed, and numerical solutions for discrete eigenmodes with various free parameter values are presented.
UR - http://www.scopus.com/inward/record.url?scp=61349201491&partnerID=8YFLogxK
U2 - 10.1029/2008JA013459
DO - 10.1029/2008JA013459
M3 - 期刊論文
AN - SCOPUS:61349201491
SN - 2169-9380
VL - 113
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
IS - 12
M1 - A12209
ER -