Simulations of resonant Alfvén waves generated by artificial HF heating of the auroral ionosphere D. Pokhotelov, W. Lotko, and A. V. Streltsov Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
Abstract. Numerical two-dimensional two-fluid MHD simulations of dynamic
magnetosphere-ionosphere (MI) coupling have been performed to model the effects
imposed on the auroral ionosphere by a powerful HF radio wave transmitter. The
simulations demonstrate that modifications of the ionospheric plasma temperature
and recombination due to artificial heating may trigger the ionospheric feedback
instability when the coupled MI system is close to the state of marginal stability.
The linear dispersion analysis of MI coupling has been performed to find the
favorable conditions for marginal stability of the system. The development of
the ionospheric feedback instability leads to the generation of shear waves
which resonate in the magnetosphere between the heated ionospheric E-region and
the strong gradient in the speed at altitudes of 1-2 RE. The application
of the numerical results for the explanation of observations performed by low-orbiting
satellites above the high-latitude ionosphere heated with a high power ground-based
HF transmitter is discussed.
Citation: Pokhotelov, D., Lotko, W., and Streltsov, A. V.: Simulations of resonant Alfvén waves generated by artificial HF heating of the auroral ionosphere, Ann. Geophys., 22, 2943-2949, doi:10.5194/angeo-22-2943-2004, 2004.