Intracloud Cloud-to-Cloud Anvil Crawlers Cloud-to-Air Sprites and Jets
Predicted in 1920s by C.T.R. Wilson Officially documented July 6, 1989 Not categorized as lightning, but a electrical discharge phenomena Placed into separate categories: sprites, elves, fairies, gnomes, jets, and halos Duration: 1-60 ms Effect atmospheric composition
Sprites: ◦ low luminosity ◦ associated with positive cloud to ground and intracloud lightning ◦ altitude range: ~50-90 km ◦ Ionized balls travel up, and then down (process repeats several times) ◦ tendrils on bottom and branches on top ◦ red due to nitrogen ionization ◦ Cold plasma, acts as fluorescence ◦ Duration: ~10 ms
Blue Jets: higher luminosity associated with strong hail storms altitude range: ~20 km - 50 km typically conical w./ 15° opening color due to low-emission ionization of N₂ Duration: ~20 ms ELVES (Emission of Light and Very Low Frequency Perturbations due to Electromagnetic Pulse Sources): o low luminosity o associated with any cloud to ground lightning and short EMPs (electromagnetic pulses) o usually accompanied by sprites o altitude range: ~ km o rapidly expanding red disk: ~ 300 km diameter o Duration: <1 ms
“…Plasma! Electrons Are Free!” - They Might Be Giants
Ionized particles equal parts of cations and electrons mostly neutral atoms Lower electron densities w/ higher altitudes and temperatures Absorption of X-ray, UV, and shorter wavelengths due to Solar radiation Higher density in high and polar latitudes
Composition: N₂ and O₂ D: lowest; 60 – 90 km NO, N₂, and O₂ ions Loss of energy due to recombination HF radio waves not deflected Disappears at night
E: middle; km mostly O₂ ions HF radio deflected Most layer disappears at night; remaining increases altitude F: highest; 200 – 500 km Mostly O ions; breaks up into two levels during day F1: deformation F2: responsible for most skywave propagation deflecting HF radio waves
Chapman Functions form basis for modeling N(h)=electron densityN 0 =max electron density h 0 =height of max densityh=altitudeH s =effective scale height Plasma Frequency
"Ionosphere - Wikipedia, the free encyclopedia." Wikipedia, the free encyclopedia. N.p., n.d. Web. 6 June "Lightning Types and Classifications : Storm Highway Weather Library." Storm Highway :: Storm Chasing, Photography, Video and Travels by Dan Robinson. N.p., n.d. Web. 6 June "TLE - an introdution." Sprites, Jets and other Transient Luminous Events. N.p., n.d. Web. 10 June "Upper-atmospheric lightning - Wikipedia, the free encyclopedia." Wikipedia, the free encyclopedia. N.p., n.d. Web. 10 June atmospheric_lightning. atmospheric_lightning