Accession Number : ADP006521

Title :   Modification of the Lower Ionosphere in Lighting-Induced Electron Precipitation Events and through VLF Heating,

Corporate Author : STANFORD UNIV CA SPACE TELECOMMUNICATIONS AND RADIOSCIENCE LAB

Personal Author(s) : Inan, Umran S.

Report Date : OCT 1990

Pagination or Media Count : 12

Abstract : Different mechanisms by which VLF waves from ground-based sources modify the nighttime lower ionosphere (D-region) are discussed. One process by which the ionosphere is regularly disturbed involves the precipitation of short (<2s) bursts of energetic (>40 keV) electrons out of the radiation belts in gyroresonant interactions with whistler waves launched by lightning discharges. A second process involves direct upward coupling of lightning electric fields to the lower ionosphere leading to intense electric fields and ionization enhancements. A third process is the heating of the lower ionosphere by upgoing VLF waves from ground-based transmitters and lightning, leading to up to 100% increase in electron temperature at 80-90 km altitudes 1.

Descriptors :   *LIGHTNING, *PRECIPITATION, *WHISTLERS, *IONOSPHERIC MODIFICATION, COUPLINGS, ELECTRIC FIELDS, ELECTRONS, GROUND BASED, HEATING, INTERACTIONS, IONIZATION, IONOSPHERE, RADIATION BELTS, RUPTURE, TEMPERATURE, RADIO TRANSMITTERS, D REGION, ELECTRON ENERGY.

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE