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Multifrequency study of ionospheric scintillation at Ascension Island
Author(s) -
Franke S. J.,
Liu C. H.,
Fang D. J.
Publication year - 1984
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs019i003p00695
Subject(s) - scintillation , spectral index , ionosphere , amplitude , physics , interplanetary scintillation , spectral density , power law , index (typography) , astrophysics , geology , spectral line , computational physics , optics , geophysics , astronomy , mathematics , nuclear physics , detector , statistics , plasma , coronal mass ejection , world wide web , computer science , solar wind
Multifrequency amplitude scintillation data at L and C bands from the equatorial region at Ascension Island are used to study the spectral index n for the scintillation index S 4 . The average frequency dependence of the scintillation index (S 4 ) is found to be f −1.68 . It is shown that the spectral index tends to be larger for events which occur after 2030 local time than for events which occur before 2030. This may indicate temporal evolution of the irregularity spectrum. Model studies based on a two component power law irregularity spectrum are applied to relate changes in n to spectral evolution and to show that the observations are consistent with recent in situ measurements. Possible geophysical implications are also discussed.