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TitleInvestigation of localized 2D convection mapping based on artificially generated Swarm ion drift data
AuthorFiori, R A D; Boteler, D H; Koustov, A V; Knudsen, D; Burchill, J K
SourceJournal of Atmospheric and Solar-Terrestrial Physics vol. 114, 2014 p. 30-41,
Alt SeriesEarth Sciences Sector, Contribution Series 20130463
Mediapaper; on-line; digital
File formatpdf
Subjectsgeophysics; remote sensing; satellite imagery; ionosphere; convection
Illustrationsmodels; tables; plots; histograms
ProgramNorthern Canada Geohazards Project, Public Safety Geoscience
AbstractIonospheric plasma flow is an indicator of the interconnection between the solar wind, interplanetary magnetic field (IMF), and Earth's magnetosphere. Ionospheric convection has been mapped in the past using either a widespread data set for instantaneous convection mapping over a short time period or data from an instrument measuring convection in a spatially confined region over a long time period for the purpose of building a statistically averaged convection pattern. This study explores convection mapping using a spherical cap harmonic analysis (SCHA) technique within a localized spherical cap based on data that will be available from the Swarm three-satellite constellation. Convection is mapped in the vicinity of hypothetical Swarm satellite tracks where it is adequately constrained by data. By using statistical models to emulate Swarm measurements, we demonstrate that such mapping can be successful based on data from the Swarm A and Swarm B satellites. Convection is divided into well constrained and poorly constrained subsets to determine parameters characterizing goodness-of-fit based on known quantities. Using the subset of well constrained maps, it is determined that convection is best mapped for a spherical cap having an angular radius of vc=10°. The difference between the maximum mapped convection and the maximum velocity measured along the satellite track (dv) is introduced to evaluate goodness-of-fit. For the examples presented in this paper, we show that a threshold value of dv=281 m/s successfully differentiates between well and poorly constrained maps 77.6% of the time. It is shown that convection can be represented over a larger region through the use of multiple spherical caps.
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. Space weather processes in the polar ionosphere are the subject of an upcoming investigation by the Swarm satellite mission. New knowledge generated by the mission will contribute to the future development of space weather services. This paper examines convection mapping using localized electric field measurements from the Swarm satellites.