A. V. Gurevich

Runaway electron mechanism of air breakdown and preconditioning during a thunderstorm

Abstract The possibility is considered of an avalanche-type increase of the number of runaway electrons leading to a new type of electric breakdown of gases. This type of breakdown could take place in the atmosphere during a thunderstorm stimulated by cosmic ray secondaries.

Lightning initiation by simultaneous effect of runaway breakdown and cosmic ray showers

Abstract The combined action of cosmic ray showers (CRS) and runaway breakdown (RB) on thunderstorm atmosphere is studied. The ionization of atmosphere produced by CRS core being strongly amplified in RB conditions is shown to be sufficient to generate a highly ionized plasma region. Electric polarization of this plasma region is manifested in a significant local amplification of a thunderstorm electric field, what could result in a local electric breakdown and lead to initiation of lightning. Experiments which could check the predictions of the theory are proposed.

Magnetic zenith effect in ionospheric modifications

The theory of ionospheric modification for the beam of powerful radio emission directed along magnetic field lines is developed. Nonlinear process of beam self-focusing on striations is shown to determine strong amplification of heating and acceleration of plasma electrons. It results in a dramatic enhancement of optic emission from the magnetic zenith region in ionospheric F-layer. An excellent agreement between the theory and recent fundamental observations at HAARP facility (Alaska) [T. Pedersen et al., Geophys. Res. Lett. (2002), in press] is demonstrated.

High energy cosmic ray particles and the most powerful discharges in thunderstorm atmosphere

The runaway breakdown -- extensive atmospheric shower discharge (RB - EAS) excited in thunderstorm atmosphere by high energy cosmic ray particles (

Self-oscillations and bunching of striations in ionospheric modifications

\epsilon_p>10^{17} - 10^{19}

Nonlinear structuring and southward shift of a strongly heated region in ionospheric modification

eV) generate very powerful radio pulse. The RB - EAS theory is compared with observations of radio pulses. An agreement between the theory and experiment is established. The existence of nowaday satellite and ground based systems which obtain regularly a large amount of observational radio data could allow to use them in combination with other methods for effective study of high energy cosmic ray particles

Radio emission of lightning initiation

Abstract Based on the theory of stationary striations created in ionospheric modifications by powerful radio waves, as developed by Gurevich et al. [Phys. Lett. A 206 (1995) 247], the existence of self-oscillations of striations and of a large scale nonlinear structuring in a modified region is predicted. The theory is shown to be in agreement with existing observational data. Direct in situ rocket measurements of the electron temperature inside the striations, analogous to the recent plasma density measurements [M.C. Kelley et al., J. Geophys. Res. 100 (1995) 17 367], are desirable.

Radio emission due to simultaneous effect of runaway breakdown and extensive atmospheric showers

Abstract The theory of self-focusing on striations for the powerful radio wave beam propagating in the northern or midlatitude ionosphere is developed. It is demonstrated that focusing lead to formation of a large scale nonlinear structure aligned magnetic field. It consists of a number of closely packed solitons — bunches of striations. The anomalous absorption of a pump wave trapped in solitons lead to the strong ohmic heating of electrons in the focused region. The theory is in a good agreement with the results of recent observations of optic emission and temperature enhancement in northern ionospheric modification experiments.

Nonlinear structuring of the ionosphere modified by powerful radio waves at low latitudes

AbstractThe wide band (0.1–30 MHz) high time resolution (16 ns) radio interferometer is constructed and used to study the initialradio emission of lightning. It is established that the first lightning radio pulse is bipolar and its form, width and amplitude agreewith theoretical predictions [Phys. Lett. A 301 (2002) 320].From observations follows: (a) The runaway breakdown (RB) conditions are fulfilled in thundercloud during noticeable partof storm time; (b) The lightning is initiated by a combined action of RB and extensive atmospheric shower generated by cosmicray particle having the energy ∼10 16 eV.The RB effect in thunderclouds plays a role of lightning “spark chamber” and can be used for radio detection of high energycosmic ray particles.  2003 Published by Elsevier Science B.V. 1. IntroductionThe theory of radio emission generated duringthunderstorm by cosmic ray particles having highenergy was developed by Gurevich et al. [1]. Theemission should have a high intensity due to thecombined action of runaway breakdown and extensiveatmospheric shower.Runaway breakdown is a new physical concept ofan avalanche type increase of a number of energeticelectrons in gas under the action of the electric fieldwhich was proposed by Gurevich et al. [2]. Theavalanche can grow in electric field

Modulational instability and formation of a nonlinear oscillatory structure in a focusing' medium

The theory of radio emission generated during thunderstorm by cosmic ray particles having high energy e is developed. The emission is shown to have a form of bipolar microsecond radio pulse with characteristic frequency 1–10 MHz. Due to combined action of runaway breakdown and extensive atmospheric shower the emission intensity is high. The radio pulse could be observed for e 10 17 eV up to distances 100–300 km. Thus the runaway breakdown in thunderclouds can play a role of a “spark chamber” for radio detection of high energy particles.  2002 Published by Elsevier Science B.V.