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TitleStatistical analysis of large and extreme global ionospheric total electron content
AuthorNikitina, LORCID logo; Fiori, R A DORCID logo; Waddington, G H
SourceJournal of Atmospheric and Solar-Terrestrial Physics vol. 229, 105841, 2022 p. 1-9,
Alt SeriesNatural Resources Canada, Contribution Series 20210275
Mediapaper; on-line; digital
File formatpdf; html
ProvinceCanada; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut
NTS1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65; 66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560
Lat/Long WENS-180.0000 180.0000 90.0000 -90.0000
Subjectsgeophysics; Science and Technology; Nature and Environment; Transport; ionosphere; ionospheric currents; statistical analyses; latitude; Natural hazards; global navigation satellite systems (GNSS); Global positioning systems; Time; Communications equipment; Civil aviation; Radio; Methodology
Illustrationsplots; tables; geoscientific sketch maps; time series; bar graphs
ProgramPublic Safety Geoscience Assessing space weather hazards
Released2022 02 19
AbstractIonospheric disturbances, due to photoionization and energetic particle precipitation, occurring both on a regular recurring basis, and heightened due to space weather, impact global positioning, navigation, and timing services provided by Global Navigation Satellite Systems (GNSS). The development of operational services to mitigate the risks to users requires knowledge of how space weather impacts critical systems, and the frequency and magnitude of ionospheric disturbances including extreme events. Analysis of the largest values of total electron content (TEC) is important for the assessment of space weather hazards for systems sensitive to ionospheric effects on radio wave propagation and for the development of risk mitigation strategies. In this study, twenty years of global TEC maps are analyzed to determine the global distribution of the daily maximum TEC. Maximum TEC is shown to reach magnitudes of about 200 TECU in extreme cases, with the largest TEC normally observed at equatorial latitudes. A generalized extreme value distribution has been applied to the daily global maximum TEC and for the high (60°-90°; -90° to -60°), mid (30°-60°; -60° to -30°), and low-latitude (0°-30°; -30°-0°) regions in geographic latitudes to determine the 1-in-44 year (4 solar cycles) and 1-in-100 year maximum TEC with a 95% confidence interval. Additionally, the return period for TEC thresholds defined for safe operation by the International Civil Aviation Organization are discussed. Extreme values provide criteria for the development of operational systems and vulnerability assessment of critical systems dependant on GNSS.
Summary(Plain Language Summary, not published)
Accuracy and availability of global navigation services, e.g. GNSS, depend on ionosphere conditions. Largest disturbances of the electron density in the ionosphere are caused by fluxes of solar energetic particles during space weather events. These perturbations impact satellite-receiver signal propagation and can cause degradation of navigation systems which affect aviation, marine navigation, geological survey and other users of navigation systems. To mitigate risks from ionosphere disturbances to users, developers of an operational service need knowledge of frequency and magnitude of Ionospheric disturbances, especially during large space weather events. This paper provides statistical assessment of perturbations of the total electron content in the ionosphere separately for equatorial, mid-latitude and high-latitude areas and provides as well estimation of one in 4 solar cycles (44 years) and one in 100 years largest possible Ionospheric perturbations which could happen after large space weather event. This paper also includes discussion how frequent perturbations in the ionosphere exceed moderate and severe activity levels which were defined by the International Civil Aviation Organization for safe aviation operation.

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