Robert sent in this link – www.dailymail.co.uk/sciencetech/article-5008797/Red-sprite-lightning-sto… … Red sprites are electrical bursts of lightning active above thunderstorms. They are red at higher altitudes, fading to blue at lower altitudes. The images below were taken in Oklahoma (big wide skies on the praire) on October 4th ..
… sprites are visible in the ionosphere – between 37 and 56 miles above the surface of the Earth.