Understanding Lightning: Causes of Ionisation and its Impact on Atmosphere

[avito009]

Please explain this to me: "Electric force manifests itself in atmosphere where the atoms are ionised and that leads to lightening".

why and how are atoms ionised in the above case? How does this ionisation cause lightening?

 

[enorbet]

Greetings
First of all there are many forms of lightning and more being discovered from space. I assume you are referring to the common forked streaks we see during a thunderstorm so I'll address that.

AFAIK it begins as a thermal process within clouds which results in warmer lighter objects having a positive charge gradually congregating at the top of a cloud while cooler, negatively charged particles (often ice crystals) gather at the bottom. Because this is a loose conglommeration there is air without charge between the two which creates a sort of capacitor, which when it reaches overload conditions releases that energy as the spark we call lightning.

For e fuller (and better) explanation see http://scijinks.jpl.nasa.gov/lightning/

 

[Drakkith]

You can also read more here: http://en.wikipedia.org/wiki/Lightning

I'd go into a little more detail, but I have to head to class.

 

[zoki85]

Avito, nobody knows that for sure. Internal electric fields in a thunderstorm cloud are too low to spontaneously initiate lightning

 

[A.T.]

Slow motion films of lightning can be enlightening: