Artificial ionospheric glow caused by the short-term effect of high-power RF radiation

On the effects observed during modification of the earth’s upper ionosphere by high-power short radio pulses

“…It should be assumed that the time of acceleration of electrons together with the time of their propagation from the acceleration region to the DSEE generation region (about 10 km) must not exceed 10-20 ms. Note that the appearance of electrons accelerated up to at least 4 eV in the first milliseconds and tens of milliseconds after the PW-radiator switch-on was demonstrated in the measurements of artificial optical radiation in the green line of atomic oxygen at the wavelength λ = 5577Å [38,39]. At the same time, such streams of suprathermal electrons can stimulate the development of plasma perturbations, leading to the generation of plasma turbulence outside the regions of initial-AIT excitation [40], which can cause an increase in the DSEE intensity under additional heating of the plasma by a high-power radio wave.…”

On the location and structure of the artificial 630-nm airglow patch over Sura facility

“…The artificial airglow has been studied since early 1970s at different ionospheric heating facilities, such as Arecibo (Puerto-Rico), Platteville (Boulder, Colorado), EISCAT (Tromsø, Norway), SURA (Nizhniy Novgorod, Russia), HAARP and HIPAS (Alaska). Observations of the artificial airglow are used to study the electron acceleration by HF pump-driven electrostatic plasma waves, as well as for mapping of the ionosphere (Haslett and Megill, 1974;Bernhardt et al, 1989a,b;Leyser et al, 2000;Bernhardt et al, 1991Bernhardt et al, , 2000Pedersen and Carlson, 2001;Gustavson et al, 2001Gustavson et al, , 2005Gumerov et al, 1999;Grach et al, 2004;Kosch et al, 2002aKosch et al, , 2005. Mapping of the pumped volume with CCD cameras is used for remote sensing of the large-scale irregularities of both natural and HF-pump driven origin.…”

“…The question of which candidate dominates is under long-standing theoretical discussion (Weistock and Bezzerides, 1974;Gurevich et al, 1985;Grach et al, 1986;Dimant et al, 1992;Grach, 1999;Gurevich et al, 2002;Istomin and Leyser, 2003) but still remains to be resolved. Recent experimental achievements demonstrated that for long ( 10 s), pumping electron acceleration is linked to the upper hybrid turbulence while short ( 10 ms) pump pulses provide an effective acceleration by Langmuir waves (Gumerov et al, 1999;Gustavson et al, 2001;Kosch et al, 2002b;Grach et al, 2004;Gustavson et al, 2005). Notice that Mishin et al (2004) have shown that lower hybrid waves can efficiently accelerate electrons during HF heating, although to lesser energies than Langmuir waves.…”

The “Sura” facility: Study of the atmosphere and space (a review)

“…The experiments also confirmed the "magnetic-zenith" effect, i.e., an increase in the luminescence intensity during the PW propagation in the magnetic-field direction, which was discovered for the first time on the HAARP and EISCAT polar facilities [86,87]. More rapid measurements of the luminescence in the short-lived line O( 1 S), performed using electrophotometers and supported by SEE measurements, indicate that the acceleration of electrons is determined by Langmuir waves for short (5 ms) pump pulses and by upper-hybrid waves when passing from the long-term continuous to pulsed pumping [88,89].…”