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TitreInvestigation of localized 2D convection mapping based on artificially generated Swarm ion drift data
AuteurFiori, 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, https://doi.org/10.1016/j.jastp.2014.04.004
Année2014
Séries alt.Secteur des sciences de la Terre, Contribution externe 20130463
ÉditeurElsevier
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1016/j.jastp.2014.04.004
Mediapapier; en ligne; numérique
Formatspdf
Sujetstélédétection; imagerie par satellite; ionosphère; convection; géophysique
Illustrationsmodels; tables; plots; histograms
ProgrammeNord du Canada, risque géoscience, Géoscience pour la sécurité publique
Résumé(disponible en anglais seulement)
Ionospheric 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.
Résumé(Résumé en langage clair et simple, non publié)
La météo spatiale fait référence aux conditions dynamiques du soleil et de l'environnement spatial qui peuvent influer sur les infrastructures essentielles. RNCan exploite le Centre canadien de météo spatiale et étudie les effets de la météo spatiale sur les systèmes d'alimentation électrique, les pipelines, les satellites, les installations de communications radio et le FGISM pour aider l'industrie canadienne à comprendre et à atténuer les effets de la météo spatiale. Les processus de météorologiques spatiales dans l'ionosphère polaire font l'objet d'une enquête à venir de la mission du satellite Swarm. Les nouvelles connaissances générées par la mission contribueront au développement futur des services de météorologie de l'espace. Ce document examine la cartographie de convection en utilisant des mesures localisées du champ électrique provenant des satellites Swarm.
GEOSCAN ID293667