Lightning-associated precipitation of MeV electrons from the inner radiationbelt

Journal Article · Mon Feb 01 04:00:00 EST 1988 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL015i002p00172· OSTI ID:5311388

Inan, U S; Burgess, W C; Wolf, T G; Shafer, D C; Orville, R E

Transient perturbations of subionospheric very low frequency (VLF) radiowave signals provide new evidence for lightning-induced electron precipitation (LEP) events involving short (<1 s) bursts of >1 MeV electrons from the earth's inner radiation belt at Lless than or equal to1.8. The signal amplitude changes are attributed to increased absorption in the earth-ionosphere waveguide and/or alterations of the waveguide mode structure due to localized secondary ionization enhancements produced in the nighttime lower ionosphere and the mesosphere by the precipitating electrons. The otherwise stably trapped electrons are believed to be scattered in pitch angle during cyclotron resonant interactions in the magnetosphere with the lightning-generated whistler waves. That some precipitation bursts consist partly of MeV electrons is suggested by (i) confinement of the perturbed subionospheric signal path to low magnetic latitudes (Lless than or equal to1.8), for which corresponding electron energies for gyroresonance with typical whistler-wave frequencies in the magnetosphere are >1 MeV, and (ii) the temporal signatures of the perturbation events, which often exhibit an unusually rapid initial recovery (time constant of tau<1 s) followed by further recovery at rates believed characteristic of less energetic events (tauapprox.5--20 s). The latter is interpreted as a manifestation of the rapid variation with altitude of the effective loss rate for excess ionization over an exceptionally wide range of mesospheric altitudes (40--70 km) penetrated by the >1 MeV electrons. copyright American Geophysical Union 1988

• Research Organization: STAR Laboratory, Stanford University, Stanford, California
• OSTI ID: 5311388
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 15:2; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
&amp; Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED-PARTICLE PRECIPITATION
CYCLOTRON RESONANCE
EARTH ATMOSPHERE
ELECTRIC DISCHARGES
ELECTROMAGNETIC RADIATION
ELECTRON PRECIPITATION
GYROFREQUENCY
IONIZATION
IONOSPHERE
LIGHTNING
MESOSPHERE
NOISE
PLANETARY IONOSPHERES
RADIATION BELTS
RADIATIONS
RADIO NOISE
RADIOWAVE RADIATION
RESONANCE
WAVEGUIDES
WHISTLERS