SFERICSSFERICS'Sferics'
A network of three radio direction finding stations is usually employed, the
stations being approximately 1000 miles apart. Lightning produces radio waves,
known as 'sferics' which are detected by the equipment at ranges of up to 2000
miles. The best results are usually obtained in the area within 200 to 600 miles
of the network. The position is determined by triangulation from three stations
and the error is never less than 30 miles and may be as large as 300 miles.(1)
The Networks
The Bureau's equipment was initially arranged in two networks:
The Queensland Network; Brisbane Airport(Eagle Farm), Charleville and Townville(Garbutt)
commenced in 1957. Cloncurry was added in January 1962.(1)(4)
The Southern Ocean Network; Melbourne(Laverton), Perth Airport(Guilford) and
Wilkes in Antarctica.(1)(4)
Beyond this, plans were made for installations at; Hobart, Kalgorlie & Adelaide(1960), Carnarvon, Kalgorlie, and Pt. Hedland(1962)(2). Operators recall that by 1970 there were installatons at Geraldton, Albany, Forrest, and Pt. Hedland (3). So some of the purchased sets may have not been finally located at the those planned sites. Certainly the set at Wilkes seems to have been relocated to Pt. Hedland(2).
Observational Value
Sferics observations were useful in that they indicated areas of unstable atmosphere
and inferred the existence of frontal lines, depressions and cyclones. For aviation,
it provided an indication of areas in which thunderstorms and turbulence was
likely to be encountered.(1)
(1) Working
Paper No 48 June 1962, Notes on Sferics, Radar and Atmospheric Turbulence by
Goodman, Bath & McRae
(2) Documentation
of Installation / Projects sections
(3) Numerous
Bureau observing staff - June 2001 (private communications)
(4) Metarch papers No. 13, A very
special family: Memories of the Bureau of Meteorology 1946 to 1962 by W J Gibbs