Illumination of mesospheric irregularity by lightning discharge

Martin Füllekrug (1) , Andrew Mezentsev (1) , Serge Soula (2) , Oscar van Der Velde (3) , Adrian Evans (1)

1 Department of Electronics and Electrical Engineering [Bath]
2 LAERO - Laboratoire d'aérologie
3 Electrical Engineering Departement

Theoretical model calculations recently predicted the existence of mesospheric irregularities which assist the initiation of sprites. Here we report the experimental detection of a ∼3–19 km3 large mesospheric irregularity at ∼80–85 km height which is illuminated by the electromagnetic field of an intense positive cloud-to-ground lightning discharge. While the lightning discharge causes a prompt group of four sprites above the lightning discharge, the mesospheric irregularity is found at a horizontal distance at least ∼15–20 km away from the sprite group and it rebrightens ∼40–60 ms after the sprite group occurrence. This rebrightening is driven by a local quasi-static electric field enhancement with a charge moment ∼4–20 Ckm which causes the irregularity to develop a downward descending luminous column from ∼75–85 km height. The quasi-static electric field enhancement is caused by the reorganization of residual charge inside the thundercloud during a high-level activity of intracloud discharges with ∼10–20 pulses per ms. Such mesospheric irregularities might have an effect on the wave propagation of 100 kHz radio waves which are used for atomic time transfer and marine navigation.

Domaines: Géophysique [physics.geo-ph]; Physique Atmosphérique et Océanique [physics.ao-ph]

Martin Füllekrug, Andrew Mezentsev, Serge Soula, Oscar van Der Velde, Adrian Evans. Illumination of mesospheric irregularity by lightning discharge. Geophysical Research Letters, 2013, 40, pp.6411 - 6416. ⟨10.1002/2013GL058502⟩. ⟨insu-01394877⟩