flybywire wrote:
just if like me i hadn't guessed what cg and ic meant and didn't want to ask
this learned group

Types of Lightning Discharges

Cloud - Air lightning (c-a) is quite common where the lightning stroke
appears to stop in mid air. Also upward lightning from the cloud top
into the strat (see below).

Sprites, blue jets and elves are not very bright and rarely seen except
by pilots, astronauts and chasers watching from a long way away in
darkness. They are believed to originate from the ionosphere and are
part of the cloud charging process. More commonly associated with +CG
lightning originating from cloud tops. Presumably also stratospheric
lightning.

Ribbon lightning is where each lightning stroke is blown away from the
next one. The same effect is caused by camera shake and can be used for
lightning research (boys - bowen camera).

Bead lightning is when the discharge channel glows at different
intensities along its length.

Black lightning is caused by video (or eyes) overexposing to black when
the electronics or retina can't cope with the intense light. There's one
piece of footage which crops up quite frequently on these severe weather
programmes showing a black lightning discharge.

Heat, sheet and silent lightning are (usually IC) lightning strokes from
a long way away.

Ball lightning is a glowing plasma ball created by the discharge and
undoubtedly exists but unfortunately this phenomenon has been taken up
by those into ufo's, pyramid power, rods, invaders from outer space and
the phases of the moon affecting weather and serious research has been
stifled as a result.

Tube lightning (fulgarites) are cause by the lightning hitting sand and
creating tubes of glass (from memory - may be incorrect?).

Coloured lightning is caused by dust and other impurities in the
atmosphere (usually) giving the lightning stroke a reddish tint.

Les