Analysis of the effectiveness of ground-based VLF wave observations for predicting or nowcasting relativistic electron flux at geostationary orbit

Simms, Laura E.; Engebretson, Mark J.; Smith, A.J.; Clilverd, Mark ORCID: https://orcid.org/0000-0002-7388-1529; Pilipenko, Viacheslav; Reeves, Geoffrey D.. 2015 Analysis of the effectiveness of ground-based VLF wave observations for predicting or nowcasting relativistic electron flux at geostationary orbit. Journal of Geophysical Research: Space Physics, 120 (3). 2052-2060. https://doi.org/10.1002/2014JA020337

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Abstract/Summary

Post-storm relativistic electron flux enhancement at geosynchronous orbit has shown correlation with very low frequency (VLF) waves measured by satellite in situ. However, our previous study found little correlation between electron flux and VLF measured by a ground-based instrument at Halley, Antarctica. Here we explore several possible explanations for this low correlation. Using 220 storms (1992–2002), our previous work developed a predictive model of the post-storm flux at geosynchronous orbit based on explanatory variables measured a day or two before the flux increase. In a nowcast model, we use averages of variables from the time period when flux is rising during the recovery phase of geomagnetic storms, and limit the VLF (1.0 kHz) measure to the dawn period at Halley (9–12 UT). This improves the simple correlation of VLF wave intensity with flux, although the VLF effect in an overall multiple regression is still much less than that of other factors. When analyses are performed separately for season and IMF Bz orientation, VLF outweighs the influence of other factors only during winter months when IMF Bz is in an average northward orientation.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1002/2014JA020337
Programmes:	BAS Programmes > BAS Programmes 2015 > Space Weather and Atmosphere
ISSN:	21699380
Additional Keywords:	relativistic electron flux, VLF waves
Date made live:	09 Mar 2015 11:22 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/510016

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1002/2014JA020337

Programmes:

BAS Programmes > BAS Programmes 2015 > Space Weather and Atmosphere

ISSN:

21699380

Additional Keywords:

relativistic electron flux, VLF waves

Date made live:

09 Mar 2015 11:22 +0 (UTC)