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Three‐dimensional modeling of high‐latitude scintillation observations
Author(s) -
Chartier Alex,
Forte Biagio,
Deshpande Kshitija,
Bust Gary,
Mitchell Cathryn
Publication year - 2016
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 - 10.1002/2015rs005889
Subject(s) - scintillation , incoherent scatter , ionosphere , physics , interplanetary scintillation , standard deviation , electron density , computational physics , line of sight , phase (matter) , radar , latitude , optics , geodesy , geology , geophysics , electron , astrophysics , mathematics , plasma , statistics , astronomy , telecommunications , detector , computer science , coronal mass ejection , quantum mechanics , solar wind
Global Navigation Satellite System signals exhibit rapid fluctuations at high and low latitudes as a consequence of propagation through drifting ionospheric irregularities. We focus on the high‐latitude scintillation problem, taking advantage of a conjunction of European Incoherent Scatter Radar (EISCAT) observations and a GPS scintillation monitor viewing the same line of sight. Just after 20:00 UT on 17 October 2013, an auroral E region ionization enhancement occurred with associated phase scintillations. This investigation uses the scintillation observations to estimate the ionospheric electron density distribution beyond the spatial resolution of EISCAT (5–15 km along the line of sight in this case). Following the approach of Deshpande et al. (2014), signal propagation is modeled through a specified density distribution. A multiple phase screen propagation algorithm is applied to irregularities conforming to the description of Costa and Kelley (1977) and constrained to match the macroscopic conditions observed by EISCAT. A 50‐member ensemble of modeled outputs is approximately consistent with the observations according to the standard deviation of the phase ( σ p ). The observations have σ p = 0.23 rad, while the ensemble of modeled realizations has σ p = 0.23 + 0.04–0.04. By comparison of the model output with the scintillation observations, we show that the density fluctuations cannot be a constant fraction of the mean density. The model indicates that E region density fluctuations whose standard deviation varies temporally between 5 and 25% of the mean (EISCAT‐observed) density are required to explain the observed phase scintillations.