Boynton, R.J, Balikhin, M.A, Billings, S.A et al. (6 more authors) (2013) The analysis of electron fluxes at geosynchronous orbit employing a NARMAX approach. Journal of Geophysical Research: Space Physics (118). pp. 1500-1513.
Abstract
The methodology based on the Error Reduction Ratio (ERR) determines the causal relationship between the input and output for a wide class of nonlinear systems. In the present study, ERR is used to identify the most important solar wind parameters, which control the fluxes of energetic electrons at geosynchronous orbit. The results show that for lower energies, the fluxes are indeed controlled by the solar wind velocity, as was assumed before. For the lowest energy range studied here (24.1 keV), the solar wind velocity of the current day is the most important control parameter for the current day's electron flux. As the energy increases, the solar wind velocity of the previous day becomes the most important factor. For the higher energy electrons (around 1 MeV), the solar wind velocity registered 2 days in the past is the most important controlling parameter. Such a dependence can, perhaps, be explained by either local acceleration processes due to the interaction with plasma waves or by radial diffusion if lower energy electrons possess higher mobility. However, in the case of even higher energies (2.0 MeV), the solar wind density replaces the velocity as the key control parameter. Such a dependence could be a result of solar wind density influence on the dynamics of various waves and pulsations that affect acceleration and loss of relativistic electrons. The study also shows that statistically the variations of daily high energy electron fluxes show little dependence on the daily averaged Bz, daily time duration of the southward IMF, and daily integral inline image (where Bs is the southward component of IMF).
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2013 American Geophysical Union. This is an author produced version of a paper subsequently published in Journal of Geophysical Research: Space Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Automatic Control and Systems Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 06 Feb 2014 11:05 |
Last Modified: | 15 Sep 2014 02:40 |
Published Version: | http://dx.doi.org/10.1002/jgra.50192 |
Status: | Published |
Publisher: | American Geophysical Union |
Refereed: | Yes |
Identification Number: | 10.1002/jgra.50192 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:77103 |