Atmospheric electromagnetism: A possible disturbing influence of natural
sferics on ESE Perceptual and Motor Skills, 89, 1179-1192.
Connaughton, V., and Coauthors, 2010: Associations between Fermi Gamma-Ray Burst Monitor terrestrial gamma ray flashes and
sferics from the World Wide Lightning Location Network.
A
sferic, or radio atmospheric signal, is an electromagnetic impulse that occurs as a result of a lightning strike.
That's an important observation when it comes to using the tools we have available, especially since both airborne weather radar and
sferics like a Stormscope or Strikefinder are real-time devices.
By tracking strike rate,
sferics give instantaneous information on a storm's maturity level and of all the detectors we've tried, Avidyne's TWX670 has the best overall featureset for the price.
Very Low Frequency (VLF)
sferics are electromagnetic impulses with frequencies between 1 kHz and 100 kHz, which are generated by lightning discharges.
The limitations on
sferics are severalfold, but the biggest for our purposes is that the distance to a strike is essentially estimated based on the strength of the signal; the weaker the energy, the further away it's assumed to be.
These "sounds of lightning" are known as
sferics. Fortunately for those seeking to detect the distance and location of lightening, the character of a
sferic varies in a known way with distance and path of propagation.
Like is said about datalink radar,
sferics systems should be used as gross vectoring aids and not for storm penetration.
As always, those images should be considered only for advance planning: We've never recommended using them to navigate actual weather--even when backed up by a
sferics device.
Sferics technology in the form of a Stormscope or Strikefinder provides real-time electrical activity data.
To decide if
sferics is worth the expense for your mission, you need to understand how datalink differs from
sferics and the lighting products you're might be receiving via datalink.