Observation of two preferred propagation paths for whistler mode VLF signals received at a non-conjugate location

Whistler mode signals from NLK (24.8 kHz) were received at Dunedin, New Zealand during 1989-90. The arrival bearing of the signals shows a bimodal distribution which is consistent with the results of ALLCOCK and MCNEILL (1966), who suggested the existence of two paths with less total transmission loss than other paths. PATH 1 signals (which have a duct entry region just south of Dunedin's conjugate) are observed at all times of the year, while PATH 2 signals (which have a duct entry region just south of the NLK transmitter) show an annual variation in occurrence with a maximum in May and a minimum in November which may be a consequence of horizontal ionospheric electron density gradients near the duct entry region. Similarly preferred paths have been observed at Faraday, Antarctica from the NSS transmitter.

Details

Publication status:
Published
Author(s):
Authors: Clilverd, M.A. ORCIDORCID record for M.A. Clilverd, Thomson, N.R., Smith, A.J.

On this site: Mark Clilverd
Date:
1 January, 1992
Journal/Source:
Journal of Atmospheric and Terrestrial Physics / 54
Page(s):
1075-1079
Digital Object Identifier (DOI):
https://doi.org/10.1016/0021-9169(92)90073-T