Three-dimensional modeling of subionospheric VLF propagation in the presence of localized D region perturbations associated with lightning

Journal Article · Thu Mar 01 00:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA095iA03p02355· OSTI ID:5152651

Poulsen, W L; Bell, T F; Inan, U S ^[1]

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1. Stanford Univ., CA (United States)

A theoretical model of single-mode, subionospheric VLF wave propagation in the presence of localized perturbations of the nighttime D region has been developed. Such perturbations could be produced, for example, by lightning-induced electron precipitation associated with a characteristic type of phase or amplitude perturbation in VLF signals known as Trimpi events. The model assumes that the ionospheric perturbation is slowly varying in the horizontal plane and that mode-coupling is therefore negligible, and accounts for (1) effects of perturbations with finite extent in the dimension transverse to the great circle (GC) path between transmitter and receiver, and (2) effects of perturbations which lie off the GC path as well as on it. The formulation used for the numerical calculations depends significantly on the mode refractive index of the ambient Earth-ionosphere waveguide and the mode refractive index in the region of the perturbation. In the calculations values for the mode refractive index are determined from the electron-density-versus-altitude profiles of both the ambient and perturbed ionospheres. Values for changes in the amplitude and phase of a received signal were obtained from the model and compared with amplitude and phase measurements of a VLF signal received at Palmer Station, Antarctica, from the NPM transmitter (23.4 kHz) in Hawaii during energetic electron precipitation events.

• OSTI ID: 5152651
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:A3; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
D REGION
RADIOWAVE RADIATION
WAVE PROPAGATION
AMPLITUDES
COMPARATIVE EVALUATIONS
ELECTRON DENSITY
ELECTRON PRECIPITATION
LIGHTNING
MATHEMATICAL MODELS
REFRACTIVE INDEX
REMOTE SENSING
THREE-DIMENSIONAL CALCULATIONS
CHARGED-PARTICLE PRECIPITATION
EARTH ATMOSPHERE
ELECTRIC DISCHARGES
ELECTROMAGNETIC RADIATION
EVALUATION
IONOSPHERE
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
RADIATIONS
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena