EGU2020-2467, updated on 12 Jun 2020
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Source Altitudes of Optical Emissions Associated with TGFs

Matthias Heumesser1, Olivier Chanrion1, Torsten Neubert1, Krystallia Dimitriadou1, Christoph Köhn1, Francisco J. Gordillo-Vazquez2, Alejandro Luque2, Francisco Javier Pérez-Invernón2,3, Hugh Christian4, Richard J. Blakeslee5, Nikolai Østgaard6, Andrey Mezentsev6, and Martino Marisaldi6
Matthias Heumesser et al.
  • 1Technical University of Denmark, DTU Space, Astrophysics and Atmospheric Physics, Kgs. Lyngby, Denmark (
  • 2Instituto de Astrofísica de Andalucía (IAA - CSIC), Granada, Spain
  • 3Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany
  • 4NASA Marshall Space Flight Center, Huntsville, Alabama, USA
  • 5Earth System Science Center, University of Alabama in Huntsville, Alabama, USA
  • 6Birkeland Centre for Space Science, University of Bergen, Norway

Terrestrial Gamma-Ray Flashes (TGFs) observed from space appear to be generated after a few milliseconds of optical activity and before the onset of a main optical pulse. The pre-activity is thought to be from a propagating leader and the main optical pulse the emissions from the ensuing stroke. Scattering of photons in the cloud increases the rise time and durations of the pulses and thus allows for estimates of their optical path from their sources.

In this presentation we estimate the depth inside thunderclouds of pulses associated with more than 100 TGFs observed by the Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS). The observations are in narrow bands at 337 nm, to include the strongest line of N22P and 777.4 nm of OI, considered a strong lightning emission line. With the assumption that the sources are instantaneous and at single points within a cloud, we find optical paths for the events by using typical cloud properties. Combined with cloud top heights from a recent study on TGF producing thunderstorms, this gives an estimate at which altitude the optical detections are produced.

Data from VAISALA’s lightning location network GLD360 and NASA’s Lightning Imaging Sensor on the ISS (ISS-LIS) will be used to assess the results from the optical analysis. This includes investigations of the correlations between TGF durations, detected peak lightning current and optical path in the cloud.

How to cite: Heumesser, M., Chanrion, O., Neubert, T., Dimitriadou, K., Köhn, C., Gordillo-Vazquez, F. J., Luque, A., Pérez-Invernón, F. J., Christian, H., Blakeslee, R. J., Østgaard, N., Mezentsev, A., and Marisaldi, M.: Source Altitudes of Optical Emissions Associated with TGFs, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2467,, 2020

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