Experimental evidence of the simultaneous occurrence of VLF chorus on the ground in the global azimuthal scale – from pre-midnight to the late morning

Night-time VLF (very low frequency) chorus bursts lasting about one hour have been recorded at Finnish temporal station Kannuslehto (CGM: 64.2°; 107.9°, L = 5.3) during two VLF campaigns (on 25 February–4 March 2008 and 27 March–17 April 2011). The chorus bursts were associated with substorm develop...

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Bibliographic Details
Published in:Annales Geophysicae
Main Authors: J. Manninen, N. G. Kleimenova, O. V. Kozyreva, M. Parrot, T. Raita, T. Turunen
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2012
Subjects:
Q
Online Access:https://doi.org/10.5194/angeo-30-725-2012
https://doaj.org/article/d472639f9eb64399b1b19fdec179c96d
Description
Summary:Night-time VLF (very low frequency) chorus bursts lasting about one hour have been recorded at Finnish temporal station Kannuslehto (CGM: 64.2°; 107.9°, L = 5.3) during two VLF campaigns (on 25 February–4 March 2008 and 27 March–17 April 2011). The chorus bursts were associated with substorm development. They were accompanied by riometer absorption enhancements, which occurred simultaneously within as large longitude areas as from pre-midnight (Sodankylä, ~22:00 MLT) to the late morning (Tixie, ~03:00 MLT and Gakona, ~08:00 MLT) longitudes. It was found that the pre-midnight chorus observed on the ground occurred simultaneously with VLF chorus emissions recorded in the late morning on the low-altitude DEMETER satellite crossing the similar geomagnetic latitudes on the opposite local time sector. For the first time some evidence of simultaneous chorus burst generation in the global longitudinal scale was found (from pre-midnight to the late morning) by using direct comparison with satellite data as well as using non-direct indicator–azimuthally extended riometer absorption enhancements.