Articles | Volume 20, issue 10
https://doi.org/10.5194/angeo-20-1687-2002
https://doi.org/10.5194/angeo-20-1687-2002
31 Oct 2002
 | 31 Oct 2002

Letter to the Editor
UHF electromagnetic emission stimulated by HF pumping of the ionosphere

S. M. Grach, V. M. Fridman, L. M. Lifshits, T. S. Podstrigach, E. N. Sergeev, and S. D. Snegirev

Abstract. UHF electromagnetic emission (with a frequency near 600 MHz) from the F-region of the ionosphere pumped by an HF powerful radio wave is revealed. Possible mechanisms of the emission excitation, such as plasma mode con-version, scattering or Earth thermal noise emission off the plasma density irregularities, bremsstrahlung and excitation of high Rydberg states of the neutral particles by the accelerated electrons are discussed.

Key words. Ionosphere (active experiments; wave-particle interactions) – Solar physics, astrophysics, and astronomy (radio emissions)