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Alfvén wave boundary condition for responsive magnetosphere‐ionosphere coupling
Author(s) -
Wright Andrew N.,
Russell Alexander J. B.
Publication year - 2014
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2014ja019763
Subject(s) - magnetosphere , ionosphere , physics , boundary value problem , coupling (piping) , geophysics , computational physics , boundary (topology) , quantum electrodynamics , mathematical analysis , magnetic field , quantum mechanics , mathematics , mechanical engineering , engineering
The solution of electric fields and currents in a height‐resolved ionosphere is traditionally solved as an elliptic equation with Dirichlet or Neumann boundary condition in which the magnetosphere is represented as an unresponsive (prescribed) voltage generator or current source. In this paper we derive an alternative boundary condition based upon Alfvén waves in which only the Alfvén wave from the magnetosphere that is incident upon the ionosphere ( E x i ) is prescribed. For a uniform magnetosphere the new boundary condition reduces to ∂φ / ∂z = ( ∂ 2 φ / ∂ x 2 + 2 ∂ E xi / ∂x ) / ( μ 0V Aσ ∥ ) and is evaluated at the magnetosphere‐ionosphere interface. The resulting solution is interpreted as a responsive magnetosphere and establishes a key stage in the full self‐consistent and nonlinear coupling of the magnetosphere and ionosphere.