GPS phase scintillation associated with optical auroral emissions: First statistical results from the geographic South Pole

Abstract

Ionospheric irregularities affect the propagation of Global Navigation Satellite System (GNSS) signals, causing radio scintillation. Particle precipitation from the magnetosphere into the ionosphere, following solar activity, is an important production mechanism for ionospheric irregularities. Particle precipitation also causes the aurorae. However, the correlation of aurorae and GNSS scintillation events is not well established in literature. This study examines optical auroral events during 2010–2011 and reports spatial and temporal correlations with Global Positioning System (GPS) L1 phase fluctuations using instrumentation located at South Pole Station. An all‐sky imager provides a measure of optical emission intensities ([OI] 557.7 nm and 630.0 nm) at auroral latitudes during the winter months. A collocated GPS antenna and scintillation receiver facilitates superimposition of auroral images and GPS signal measurements. Correlation statistics are produced by tracking emission intensities and GPS L1 σφ indices at E and F‐region heights. This is the first time that multi‐wavelength auroral images have been compared with scintillation measurements in this way. Correlation levels of up to 74% are observed during 2–3 hour periods of discrete arc structuring. Analysis revealed that higher values of emission intensity corresponded with elevated levels of σφ. The study has yielded the first statistical evidence supporting the previously assumed relationship between the aurorae and GPS signal propagation. The probability of scintillation‐induced GPS outages is of interest for commercial and safety‐critical operations at high latitudes. Results in this paper indicate that image databases of optical auroral emissions could be used to assess the likelihood of multiple satellite scintillation activity.

GPS scintillation effects associated with polar cap patches and substorm auroral activity: direct comparison

“…The orientation of each image is geographic north to the top, and west to the left. In previous studies, when combining the ASIP and GPS observations, the mapping of GPS satellite locations to the Ionospheric Piercing Points (IPPs, usually assuming the ionosphere to be an infinitesimal thin layer with altitude of 350 km) and mapping optical emission to some height by assuming a fixed altitude were used (Smith et al 2008;Kinrade et al 2013;Prikryl et al 2013). However, as our GPS receiver and ASIP are colocated, we project the azimuthal and elevation angle of GPS satellites onto each image.…”

“…By comparing the GPS data with radio instruments, Prikryl et al (2010) claimed that the polar cap patches are the main contributors to scintillation-causing irregularities in the polar cap. In the case of auroral arcs, strong correlations between GPS phase scintillations and optical auroral emissions were found (Kinrade et al 2013). However, no direct comparisons of scintillation effects associated with different ionospheric phenomena were studied: the question of which class of phenomena has the strongest impacts on GPS signals remains unanswered.…”

Observations of GPS scintillation during an isolated auroral substorm

“…As stated here, the type of auroral form varies drastically depending on the phase of the substorm; thus, the characteristics of ionospheric scintillation at auroral latitudes should be discussed in terms of the substorm phase. However, most previous auroral scintillation studies have investigated the response of GPS scintillation to the appearance of relatively quiet arcs at latitudes higher than the auroral region (i.e., in the polar cap region) (e.g., Kintner et al 2007;Prikryl et al 2013a;Kinrade et al 2013). Recently, Prikryl et al (2010Prikryl et al ( , 2013b introduced several intervals where moderate GPS scintillations were detected at auroral latitudes (Yellowknife and Fort Smith in Canada) in close association with auroral breakups observed by ground-based all-sky cameras.…”

The Behaviors of Ionospheric Scintillations Around Different Types of Nightside Auroral Boundaries Seen at the Chinese Yellow River Station, Svalbard

“…The cusp region scintillations are long lasting as compared to the night time auroral scintillation. The scintillation generated in the cusp is associated with the ionospheric irregularity perturbation in the cusp region as well as cusp region particle precipitation, whereas, nighttime auroral oval scintillations are associated with the nightside energetic particle precipitation giving rise to auroral emissions (Prikryl et al, 2010(Prikryl et al, , 2011(Prikryl et al, , 2014Jiao et al, 2013;Kinrade et al, 2013;Hosokawa et al, 2014;Jin et al, 2014 and references therein). Inside the auroral oval there are some regions, where the amplitude scintillations are stronger as compared to the phase scintillations and they are supposed to be the regions having strong particle precipitations around the existing polar cap patches (Wang et al, 2016).…”