EXCITATION OF PLASMA-WAVES IN THE IONOSPHERE CAUSED BY ATMOSPHERIC ACOUSTIC-WAVES

The transformation of atmospheric acoustic waves into plasma waves in the ionosphere is investigated. The transformation mechanism is based on plasma wave exitation by growing acoustic waves, when a frequency/w avelength matching situation is reached. The interaction of acoustic a nd plasma waves occurs through collisions of neutral particles with io ns. For the case of ion-sound waves, oscillations on ion cyclotron fre quency and Alfven waves is considered. A peculiarity of Alfven waves i s the wide frequency band which may be stimulated through wave-wave in teraction.