I'm currently designing a magic system themed around the four elements of nature (yeah, I know, so original) and I wanna take the Avatar: TLA/Korra approach where, in addition to the four elements themselves, the characters can also control other fragments of nature derivative of/associated with their assigned elements. So earth mages can control stone and sand, water mages can control water pressure, ice and steam, and fire mages can control flame and heat. I've only got air left to figure out now, and since I've assigned my fire mages with heat instead of electricity/lightning, I thought that my air mages would be prefect candidates for such an ability.

The problem however, is that I don't know how to incorporate electricity manipulation into my air mages skillset in a way that makes scientific sense. Ice makes sense as an extension of water-based abilities since if you can control water, you could theoretically control its temperature and lower it enough to the point of solidification (same goes for steam, but in reverse). My mages are basically like your run-of-the-middle air elementals in that they can control wind and can create/manipulate tornadoes and wind streams, but in what way would they need to manipulate their element in order to create and control electricity? I'm assuming things such as atmospheric electricity, air molecules, air current friction and air ionization may have some part to play in helping me solve this little query of mine, but I don't know nearly enough about any of these things to construct the answer I'm looking for.