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TitleHigh-latitude GPS phase scintillation and cycle slips during high-speed solar wind streams and interplanetary coronal mass ejections: a superposed epoch analysis
AuthorPrikryl, P; Jayachandran, P T; Mushini, S C; Richardson, I G
SourceEarth, Planets and Space vol. 66, 2014 p. 1-10,
Alt SeriesEarth Sciences Sector, Contribution Series 20130496
Mediapaper; on-line; digital
File formatpdf
Subjectsgeophysics; extraterrestrial geology; geomagnetism; geomagnetic fields; geomagnetic variations; magnetic interpretations; magnetic disturbances; magnetic field; solar variations; solar energy; global positioning system
ProgramNorthern Canada Geohazards Project, Public Safety Geoscience
AbstractResults of a superposed epoch (SPE) analysis of occurrence of phase scintillation and cycle slips at high latitudes keyed by arrival times of high speed solar wind streams (HSS) and interplanetary coronal mass ejections (ICME) for years 2008-2012 are presented. Phase scintillation index cotangent is obtained in real time from L1 signal recorded at the rate of 50 Hz by specialized GPS Ionospheric Scintillation and TEC Monitors (GISTMs) deployed as a part of the Canadian High Arctic Ionospheric Network (CHAIN). The phase scintillation, mapped as a function of magnetic latitude and magnetic local time, occurs predominantly on the dayside in the cusp and in the nightside auroral oval. The scintillation occurrence peaks on days of HSS or ICME impacts at the Earth¿s magnetosphere, and tapers off a few days later, which is similar to day-to-day variability of geomagnetic activity and riometer absorption at high latitudes. ICMEs that are identified as magnetic clouds are significantly more geoeffective, particularly in triggering auroral substorm activity, than HSSs and ICMEs with no or weak magnetic cloud characteristics. Magnetic clouds result in higher occurrence, and thus probability, of scintillation in the nightside auroral zone on their arrival day. The SPE analysis results are used to obtain cumulative probability distribution functions for the phase scintillation occurrence that can be employed in probabilistic forecast of phase scintillation at high latitudes (Prikryl et al., 2012).
Summary(Plain Language Summary, not published)
Space weather refers to the dynamic conditions on the Sun and in the space environment, in particular, in the near-Earth environment, that can affect critical infrastructure. NRCan operates the Canadian Space Weather Forecast Centre and conducts research into space weather effects on power systems, pipelines, radio communications and GNSS positioning to help Canadian industry understand and mitigate the effects of space weather. This paper examines statistical occurrence of GNSS scintillation at high latitudes. The scintillation is closely linked to arrival time of solar wind disturbances. A method of probabilistic forecasting of scintillation occurrence is proposed. This provides information to guide the design of space weather hazard forecasting.