Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.554435
Title: Analytical modelling of multi-spacecraft reconnection layer measurements at the magnetopause
Author: Crofts, Jonathan Daniel
Awarding Body: University of Sussex
Current Institution: University of Sussex
Date of Award: 2011
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Abstract:
An approach to determine and analyse the structure of Petschek-type magnetic reconnection is developed. This is achieved by extending an analytical model based on the Rankine-Hugoniot wave equation for shock jump conditions and is described in terms of its past applications and limitations. The model is applied to data from the CLUSTER multi-spacecraft mission using a boundary condition method optimised by two interlinked genetic algorithms. Case studies for a range of locations within the magnetopause region and local conditions are described and subjected to fluid and particle analyses to confirm the presence of reconnective signatures. Genetic algorithms are used to optimise the fit of the model, by modifying the boundary condition selection and internal structure parameters. This information then facilitates the construction of a more accurate modelled layer structure for each event. The calculated values for state variables within these layers are compared quantitatively and qualitatively to the magnetopause boundary crossings present in the CLUSTER data. Case study results are summarised and compared before being compiled into quantitative statistics for describing the local and possibly global applicability of the model. The fast application of these methods by means of an automatic process to a large set of data is described, as are the wider possibilities arising from this and the limitations of model, methods and data. These results are used to support several assertions. Firstly, that this model is indeed applicable, within its limitations, to the study of reconnection events within the magnetospheric environment. It can also facilitate deeper studies of individual reconnection events, in addition to being employed as a basis to classify wider statistical trends in spatio-temporal structures.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.554435  DOI: Not available
Keywords: QB0460 Astrophysics ; QC Physics
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