Ionization in atmospheres of brown dwarfs and extrasolar planets VI: properties of large-scale discharge events

R.L. Bailey, Christiane Helling, G. Hodosán, C. Bilger, C.R. Stark

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)
5 Downloads (Pure)


Mineral clouds in substellar atmospheres play a special role as a catalyst for a variety of charge processes. If clouds are charged, the surrounding environment becomes electrically activated, and ensembles of charged grains are electrically discharging (e.g., by lightning), which significantly influences the local chemistry creating conditions similar to those thought responsible for life in early planetary atmospheres. We note that such lightning discharges contribute also to the ionization state of the atmosphere. We apply scaling laws for electrical discharge processes from laboratory measurements and numerical experiments to DRIFT-PHOENIX model atmosphere results to model the discharge's propagation downward (as lightning) and upward (as sprites) through the atmospheric clouds. We evaluate the spatial extent and energetics of lightning discharges. The atmospheric volume affected (e.g., by increase of temperature or electron number) is larger in a brown dwarf atmosphere (10^8-10^10 m3) than in a giant gas planet (10^4-10^6 m3). Our results suggest that the total dissipated energy in one event is <10^12 J for all models of initial solar metallicity. First attempts to show the influence of lightning on the local gas phase indicate an increase of small carbohydrate molecules like CH and CH2 at the expense of CO and CH4. Dust-forming molecules are destroyed and the cloud particle properties are frozen in unless enough time is available for complete evaporation. We summarize instruments potentially suitable to observe lightning on extrasolar objects.
Original languageEnglish
Article number43
Number of pages19
JournalAstrophysical Journal
Issue number1
Publication statusPublished - 20 Mar 2014


  • Astrobiology
  • Brown dwarfs
  • Planets and satellites: atmospheres
  • Plasmas
  • Radiation mechanisms
  • Non-thermal
  • Stars: activity


Dive into the research topics of 'Ionization in atmospheres of brown dwarfs and extrasolar planets VI: properties of large-scale discharge events'. Together they form a unique fingerprint.

Cite this