An interhemispheric comparison of GPS phase scintillation with auroral emission observed at the South Pole and from the DMSP satellite

P Prikryl ,Baiqi Ning Baiqi Ning,Vincenzo Romano Vincenzo Romano,Yusuke Ebihara Yusuke Ebihara,Lucilla Alfonsi Lucilla Alfonsi,Yongliang Zhang Yongliang Zhang,Cathryn N Mitchell Cathryn N Mitchell,Guozhu Li Guozhu Li,Luca Spogli Luca Spogli,Pierre J Cilliers Pierre J Cilliers,Joe Kinrade Joe Kinrade,M J Jarvis ,E Donovan ,A T Weatherwax ,D W Danskin ,G S Bust ,P T Jayachandran ,E Spanswick ,Reza Ghoddousi‐Fard ,M Terkildsen

doi:10.4401/ag-6227

Abstract

<p>The global positioning system (GPS) phase scintillation caused by high-latitude ionospheric irregularities during an intense high-speed stream (HSS) of the solar wind from April 29 to May 5, 2011, was observed using arrays of GPS ionospheric scintillation and total electron content monitors in the Arctic and Antarctica. The one-minute phase-scintillation index derived from the data sampled at 50 Hz was complemented by a proxy index (delta phase rate) obtained from 1-Hz GPS data. The scintillation occurrence coincided with the aurora borealis and aurora australis observed by an all-sky imager at the South Pole, and by special sensor ultraviolet scanning imagers on board satellites of the Defense Meteorological Satellites Program. The South Pole (SP) station is approximately conjugate with two Canadian High Arctic Ionospheric Network stations on Baffin Island, Canada, which provided the opportunity to study magnetic conjugacy of scintillation with support of riometers and magnetometers. The GPS ionospheric pierce points were mapped at their actual or conjugate locations, along with the auroral emission over the South Pole, assuming an altitude of 120 km. As the aurora brightened and/or drifted across the field of view of the all-sky imager, sequences of scintillation events were observed that indicated conjugate auroras as a locator of simultaneous or delayed bipolar scintillation events. In spite of the greater scintillation intensity in the auroral oval, where phase scintillation sometimes exceeded 1 radian during the auroral break-up and substorms, the percentage occurrence of moderate scintillation was highest in the cusp. Interhemispheric comparisons of bipolar scintillation maps show that the scintillation occurrence is significantly higher in the southern cusp and polar cap.</p>

Highlights

Rapid fluctuations of the amplitude and phase of transionospheric radio signals degrade positioning accuracy and cause cycle slips, which can lead to complete R0216 PRIKRYL ET AL.loss of signal lock and operational outages that can affect the performance of radio communication and navigation systems
Auroral arc brightening and substorm intensification are known to correlate with global positioning system (GPS) phase scintillation and cycle slips, which appear to be caused by ionospheric irregularities that are produced by auroral precipitation [Smith et al 2008, Prikryl et al 2010]
We focus on the GPS phase scintillation that is associated with aurora and riometer absorption at the poleward edge of the night-side and dayside auroral oval observed during a week-long highspeed solar-wind event

Summary

Introduction

Rapid fluctuations of the amplitude and phase of transionospheric radio signals degrade positioning accuracy and cause cycle slips, which can lead to complete. Scintillation of high-latitude global positioning system (GPS), or in general, Global Navigational Satellite System (GNSS), is caused by ionospheric irregularities that are produced by energetic particle precipitation and by patches of enhanced plasma density convecting in the polar cap. These high-latitude phenomena occur in both hemispheres, sometimes simultaneously, and they are threaded by magnetic field lines that are either closed or open; i.e., connected to the interplanetary magnetic field (IMF). We focus on the GPS phase scintillation that is associated with aurora and riometer absorption at the poleward edge of the night-side and dayside auroral oval observed during a week-long highspeed solar-wind event. The SSUSI is almost the same as a global ultraviolet imager [see Zhang and Paxton 2008]

Auroral activity and scintillation during the solarwind high-speed stream

Interhemispheric comparison of the phase scintillation occurrence