Japan Geoscience Union Meeting 2018

Presentation information

[EE] Poster

P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM12] Space Weather, Space Climate, and VarSITI

Thu. May 24, 2018 10:45 AM - 12:15 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Ryuho Kataoka(National Institute of Polar Research), Antti A Pulkkinen (NASA Goddard Space Flight Center), Kanya Kusano(名古屋大学宇宙地球環境研究所, 共同), Kazuo Shiokawa(Institute for Space-Earth Environmental Research, Nagoya University)

[PEM12-P21] Experimental evidence on the dependence of the standard GPS phase scintillation index on the ionospheric plasma drift around noon sector of the polar ionosphere

Yong WANG1, *Qing-He Zhang1, P. T. Jayachandran2, J. I. Moen3, Zan-Yang Xing1, R. Chadwick2, Yu-Zhang Ma1, J. M. Ruohoniemi4, M. Lester5 (1.Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, China, 2.Physics Department, University of New Brunswick, Fredericton, New Brunswick, Canada, 3.Department of Physics, University of Oslo, Oslo, Norway, 4.Bradley Department of Electrical and Computer Engineering, Virginia Tech., Blacksburg, Virginia, USA, 5.Department of Physics and Astronomy, University of Leicester, Leicester, UK)

Keywords:Polar ionosphere, Ionospheric scintillation, Standard scintillation indices, Plasma drift velocity, Fresnel frequency, GNSS

First ever experimental proof of a clear and strong dependence of the standard phase scintillation index (σφ) derived using Global Positioning System (GPS) measurements on the ionospheric plasma flow around the noon sector of polar ionosphere is presented. σφ shows a strong linear dependence on the plasma drift speed measured by the SuperDARN radars whereas the amplitude scintillation index (S4) does not. This observed dependence can be explained as a consequence of Fresnel frequency dependence of the relative drift and the used constant cut-off frequency (0.1 Hz) to detrend the data for obtaining standard σφ. The lack of dependence of S4 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 mid-latitude regions.