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Automated force-free flux rope identification

Smith, Andrew, Slavin, James, Jackman, Caitriona, Fear, Robert, Poh, Gang-Kai, DiBraccio, Gina, Jasinski, Jamie and Trenchi, Lorenzo (2017) Automated force-free flux rope identification Journal of Geophysical Research, pp. 1-12. (doi:10.1002/2016JA022994).

Record type: Article


We describe a method developed to automatically identify quasi force-free magnetotail flux ropes from in situ spacecraft magnetometer data. The method locates significant (greater than 1?) deflections of the north-south component of the magnetic field coincident with enhancements in other field components. The magnetic field data around the deflections are then processed using Minimum Variance Analysis (MVA) to narrow the selection down to those that exhibit the characteristics of flux ropes. The subset of candidates that fulfills the requirements are then compared to a cylindrical, linear (constant-?) force-free model. Those that can be well approximated as force free are then accepted. The model fit also provides a measure of the physical parameters that describe the flux rope (i.e., core field and radius). This process allows for the creation of a repeatable, consistent catalog of flux ropes. Automation allows a greater volume of data to be covered, saving time and allowing the exploration of potential selection biases. The technique is applied to MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) magnetometer data in the Hermean magnetotail and successfully locates flux ropes, some of which match previously known encounters. Assumptions of the method and potential future applications are discussed.

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Accepted/In Press date: 22 December 2016
e-pub ahead of print date: 25 January 2017
Organisations: Astronomy Group


Local EPrints ID: 405645
ISSN: 0148-0227
PURE UUID: fb63ed1d-18c9-4032-8a9e-d66684a47acd
ORCID for Andrew Smith: ORCID iD
ORCID for Robert Fear: ORCID iD

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Date deposited: 10 Feb 2017 10:08
Last modified: 25 Jul 2017 04:01

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Author: Andrew Smith ORCID iD
Author: James Slavin
Author: Caitriona Jackman
Author: Robert Fear ORCID iD
Author: Gang-Kai Poh
Author: Gina DiBraccio
Author: Jamie Jasinski
Author: Lorenzo Trenchi

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