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Flux tube analysis of L‐band ionospheric scintillation
Author(s) -
Shume E. B.,
Mannucci A. J.,
Butala M. D.,
Pi X.,
Valladares C. E.
Publication year - 2013
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/jgra.50285
Subject(s) - scintillation , flux (metallurgy) , interplanetary scintillation , physics , flux tube , geodesy , geophysics , ionosphere , geology , optics , magnetic flux , plasma , magnetic field , solar wind , materials science , coronal mass ejection , quantum mechanics , detector , metallurgy
This manuscript presents magnetic flux tube analysis of L‐band signal scintillation in the nighttime equatorial and low‐latitude ionosphere. Residues of the scintillation indexS 4estimated from the L‐band signals received from Geostationary Earth Orbit (GEO) satellites are employed in the analysis. TheS 4estimates have been shown to be associated with simultaneous GPS VTEC variations derived from JPL's GIPSY‐GIM package. We have applied the wavelet decomposition technique simultaneously on theS 4time series in a flux tube over the equatorial and low‐latitude regions. The technique decomposes theS 4signal to identify the dominant mode of variabilities and the temporal variations of scintillation‐producing irregularities in the context of a flux tube. Statistically significant regions of the wavelet power spectra considered in our study have mainly shown that (a) dominant plasma irregularities associated withS 4variabilities in a flux tube have periods of about 4 to 15 minutes (horizontal irregularity scales of about 24 to 90 km). These periods match short period gravity waves, (b) scintillation‐producing irregularities are anisotropic along the flux tube and in the east‐west direction, and (c) the occurrences of scintillation‐producing irregularities along the flux tube indicate that the entire flux tube became unstable. However, plasma instability occurrences were not simultaneous in most cases along the flux tube, there were time delays of various orders. Understanding the attributes of L‐band scintillation‐producing irregularities could be important for developing measures to mitigate L‐band signal degradation.