LR / VLF Propagation of Lightning

(Examples of RF Propagation by lightning strikes.)

  Current Grey Line Map.  Updates every 5 min.

Lightning creates radio frequencies that travel around the world, the same as Broadcast Stations do.  Since it obeys the same laws, based on the particular frequency your looking at, you can observe the propagation using  LR stations.  We will be watching the LR frequency around 10 kHz.  This seems to be the area where world wide lightning tends to pile up,  reception wise.   

Shown here is various plots captured over time with world wide LR stations.  The lightning strike becomes the transmitter for the two or more stations to receive.  For the first time perhaps you can actually get a visual indication of the gray line effect.  This is well known in Ham and SW listening hobbies.  With LR however, you actually get to observe where its at on the world maps.   This line is caused by the passing of night into day, and day into night.  Its not as simple as where the light is however.  The different layers of the ionosphere take time to change states and are still lit with the sun, even after its sun down on the ground.  This puts in delays of when it actually becomes the propagation enhanced grey line.  The map projections distort where the edge of the world really is as viewed from the sun.  If you look on a globe, you can better see how the light would be falling on the earth.  The last sequence of three snaps show a Grey Line passing.  Note the times at the stations in San Antonio and Wellington NZ.

Enhanced propagation ring.  The ring is going through Perth Australia.  This is temporary as the Grey Line Passes.  (10 kHz reception.)

Good example of a known EMI Problem during a Grey Line ring.

Watching a Grey Line go by.

Ghost or Mirrored strikes

Lr  triangulation cant tell which half of the world a lightning strike is on if its 180 degrees or more.  Shown here are strikes mirrored incorrectly to the other side of the world.  Looking on a Globe, you will see those two groups are on opposite sides of the world.  Something to be aware of if your DXing the other side of the world.  This is referenced to the operating stations of course.

  Example of Gulf of Mexico / Australia Strikes 180 degrees.

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