Moreover, investigation of the colinear ISR observations support the altitude assumption of scintillation producing irregularities, and PFISR derived electric field estimates suggest the source for irregularities is gradient drift instability. We obtain a repeatable and persuasive pattern, revealing that GPS phase scintillation is clustered at the auroral edges. Next, we use an assumption that the plasma irregularities are located at an altitude of 120~km, we map the optical data to this altitude and extend the GPS-ASI study over the entire field-of-view of the GPS receiver array. #Field angle omniweb freeWe present results from a collaborative study of GPS phase scintillation, optical emission brightness and ionospheric density perturbations, by virtue of data fusion procedure from the Mahali GPS array, All-Sky Imager (ASI) and the Poker Flat Incoherent Scatter Radar (PFISR).įirst, we present observations in a traditional way using colocated GPS-ASI sensors, giving us a principal pattern of the phase scintillation with respect to auroral brightness, free of any mapping ambiguities. The Mahali Global Positioning System (GPS) array (9 receivers, 15-30~km baseline distance) in central Alaska has probed auroral structures in a field aligned direction during a geomagnetic substorm on 07 October, 2015. Both of these conditions are typically featured during high solar activity. Results suggest that the necessary conditions for the observation of this type of scintillation in high-latitude regions are high levels of ionization and a strong variability of plasma dynamics. Besides confirming the high degree of complexity of the ionospheric dynamics, our multi-instrument observation identified the physical conditions that likely favor the occurrence of amplitude scintillations at high latitudes. Specifically, we combined information from scintillation parameters and recorded by multi-constellation (GPS, GLONASS and Galileo) receivers located at Concordia station (75.10°S, 123.35☎) and SANAE IV base (71.67°S, 2.84°W), with measurements acquired by the Special Sensor Ultraviolet Spectrographic Imager on board the Defense Meteorological Satellite Program satellites, the Super Dual Auroral Radar Network, the Swarm constellation and ground-based magnetometers. We investigated the ionospheric background and other conditions that prevailed when the irregularities formed and moved, following a multi-observations approach. This work attempted to investigate the physical mechanisms triggering the observed amplitude scintillations, with the aim of identifying the conditions favoring such events. In addition, although quite rare at high latitudes, clear amplitude scintillations were recorded by two Global Navigation Satellite System receivers during the main phase of the storm. The storm onset on 7 September 2017, triggered several variations in the ionospheric electron density, causing severe phase fluctuations at polar latitudes in both hemispheres.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |