Sprites as luminous columns of ionization produced by quasi-electrostatic thundercloud fields

Quasi-electrostatic (QE) fields which exist above thunderclouds after lightning discharges can lead to the formation of columnar channels of breakdown ionization and carrot-like vertical luminous structures with typical transverse dimension ∼5-10 km spaning an altitude range from ∼80 km to well below ∼50 km. The carrot-like forms closely resemble those observed in sprites. Results indicate that the appearance of optical emissions can be significantly delayed in time (∼1-20 ms) with respect to the causative lightning discharge.