Empirical predictive models of daily relativistic electron flux at geostationary orbit: Multiple regression analysis

Simms, Laura E.; Engebretson, Mark J.; Pilipenko, Viacheslav; Reeves, Geoffrey D.; Clilverd, Mark ORCID: https://orcid.org/0000-0002-7388-1529. 2016 Empirical predictive models of daily relativistic electron flux at geostationary orbit: Multiple regression analysis. Journal of Geophysical Research - Space Physics, 121 (4). 3181-3197. https://doi.org/10.1002/2016JA022414

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Abstract/Summary

The daily maximum relativistic electron flux at geostationary orbit can be predicted well with a set of daily averaged predictor variables including previous day's flux, seed electron flux, solar wind velocity and number density, AE index, IMF Bz, Dst, and ULF and VLF wave power. As predictor variables are intercorrelated, we used multiple regression analyses to determine which are the most predictive of flux when other variables are controlled. Empirical models produced from regressions of flux on measured predictors from 1 day previous were reasonably effective at predicting novel observations. Adding previous flux to the parameter set improves the prediction of the peak of the increases but delays its anticipation of an event. Previous day's solar wind number density and velocity, AE index, and ULF wave activity are the most significant explanatory variables; however, the AE index, measuring substorm processes, shows a negative correlation with flux when other parameters are controlled. This may be due to the triggering of electromagnetic ion cyclotron waves by substorms that cause electron precipitation. VLF waves show lower, but significant, influence. The combined effect of ULF and VLF waves shows a synergistic interaction, where each increases the influence of the other on flux enhancement. Correlations between observations and predictions for this 1 day lag model ranged from 0.71 to 0.89 (average: 0.78). A path analysis of correlations between predictors suggests that solar wind and IMF parameters affect flux through intermediate processes such as ring current (Dst), AE, and wave activity.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1002/2016JA022414
Programmes:	BAS Programmes > BAS Programmes 2015 > Space Weather and Atmosphere
ISSN:	0148-0227
Additional Keywords:	multiple regression, multivariable analysis, empirical modelling, relativistic electron flux prediction at geosynchronous orbit
Date made live:	22 Aug 2016 13:08 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/513193

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1002/2016JA022414

Programmes:

BAS Programmes > BAS Programmes 2015 > Space Weather and Atmosphere

ISSN:

0148-0227

Additional Keywords:

multiple regression, multivariable analysis, empirical modelling, relativistic electron flux prediction at geosynchronous orbit

Date made live:

22 Aug 2016 13:08 +0 (UTC)