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Experimental Evidence on the Dependence of the Standard GPS Phase Scintillation Index on the Ionospheric Plasma Drift Around Noon Sector of the Polar Ionosphere
Author(s) -
Wang Y.,
Zhang Q.H.,
Jayachandran P. T.,
Moen J.,
Xing Z.Y.,
Chadwick R.,
Ma Y.Z.,
Ruohoniemi J. M.,
Lester M.
Publication year - 2018
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2017ja024805
Subject(s) - scintillation , interplanetary scintillation , ionosphere , physics , amplitude , plasma , noon , phase (matter) , computational physics , geophysics , optics , atmospheric sciences , detector , nuclear physics , solar wind , coronal mass ejection , quantum mechanics
First experimental proof of a clear and strong dependence of the standard phase scintillation index (σ φ ) derived using Global Positioning System measurements on the ionospheric plasma flow around the noon sector of polar ionosphere is presented. σ φ shows a strong linear dependence on the plasma drift speed measured by the Super Dual Auroral Radar Network radars, whereas the amplitude scintillation index (S 4 ) does not. This observed dependence can be explained as a consequence of Fresnel frequency dependence of the relative drift and the used constant cutoff frequency (0.1 Hz) to detrend the data for obtaining standard σ φ . The lack of dependence of S 4 on the drift speed possibly eliminates the plasma instability mechanism(s) involved as a cause of the dependence. These observations further confirm that the standard phase scintillation index is much more sensitive to plasma flow; therefore, utmost care must be taken when identifying phase scintillation (diffractive phase variations) from refractive (deterministic) phase variations, especially in the polar region where the ionospheric plasma drift is much larger than in equatorial and midlatitude regions.