ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-22-2943-2004 Simulations of resonant Alfvén waves generated by artificial HF heating of the auroral ionosphere Pokhotelov D. 1 Lotko W. 1 Streltsov A. V. 1 Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA 07 09 2004 22 8 2943 2949 Copyright: © 2004 D. Pokhotelov et al. 2004 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/22/2943/2004/angeo-22-2943-2004.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/22/2943/2004/angeo-22-2943-2004.pdf

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 <i>R<sub>E</sub></i>. 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.