Gamma ray storms: preliminary meteorological analysis of AGILE TGFs

Meteorology of AGILE TGF observations
  • Alessandra TiberiaEmail author
  • Stefano Dietrich
  • Federico Porcù
  • Martino Marisaldi
  • Alessandro Ursi
  • Marco Tavani
A decade of AGILE
Part of the following topical collections:
  1. A Decade of AGILE: Results, Challenges and Prospects of Gamma-Ray Astrophysics


Despite the recognition from their discovery that terrestrial gamma ray flashes (TGFs) originate from thunderstorms, little is known about the TGF-producing storms. The characteristics of such thunderstorms are investigated here using meteorological data, with the aim to set up a framework of analysis to be propagated to more complete TGF archives. In this work, we present the preliminary results. As first analysis, we considered 72 events detected by the Astrorivelatore Gamma ad Immagini Leggero (AGILE) from March 2015 to June 2015, estimating their electric activity in terms of flash production. To this end, we examined World Wide Lightning Location Network lightning data in the spatial and temporal proximity of each AGILE TGFs, searching for relationship between flash rate peak and distribution and the TGF occurrence. Moreover, we analyzed the low-Earth orbiting (LEO) satellite observation of the TGF-producing storms to define, through the capabilities of microwave sensors (both active and passive), the structure of the convective storms correlated with TGF events. In particular, we focused on the Global Precipitation Measurement (GPM) observations and show here a case study observed by the dual-frequency precipitation radar (DPR). Preliminary results indicate that the TGF often occur during the most active lightning phase of the storm, while the intensity of the storm is not a key ingredient for the production of a TGF. The multisensory capability of LEO satellites provide a picture of the storm structure, that, despite the poor coverage, is an unprecedented tool to study such cloud system over remote areas and open ocean. This study framework is meant to be applied to other TGF database, such as the ones collected by other space missions (e.g., FERMI, RHESSI).


Lightning Thunderstorms TGF AGILE WWLLN 



  1. Cummer SA et al (2005) Measurements and implications of the relationship between lightning and terrestrial gamma ray flashes. Geophys Res Lett 32:L08811. CrossRefGoogle Scholar
  2. Dwyer JW et al (2005) A comparison between Monte Carlo simulations of runaway break-down and terrestrial gamma-ray flash observations. Geophys Res Lett 32:L22804. Google Scholar
  3. Fishman GJ et al (1994) Discovery of intense gamma-ray flashes of atmospheric origin. Science 264:1313CrossRefGoogle Scholar
  4. Huang Z et al (2005) The seasonal characteristics of TGF occurrences and their fingerprints in massive thunderstorms. Eos Trans AGU 86(52):AE33A0949 (Fall Meet Suppl Abstract) Google Scholar
  5. Inan US et al (2007) Terrestrial gamma ray flashes and lightning discharges. Geophys Res Lett 33:L18802. Google Scholar
  6. Labanti C et al (2009) Design and construction of the Mini-Calorimeter of the AGILE satellite. Nucl Instr Meth. Google Scholar
  7. Lay EH et al (2004) WWLLN global lightning detection system: regional validation study in Brazil. Geophys Res Lett 31:L03102. Google Scholar
  8. Le M et al (2013a) Precipitation type classification method for dual-frequency precipitation radar (DPR) onboard the GPM. Trans Geosci Remote Sens. Google Scholar
  9. Le M et al (2013b) Hydrometeor profile characterization method for dual-frequency precipitation radar onboard the GPM. Trans Geosci Remote Sens 51:3648–3658CrossRefGoogle Scholar
  10. Marisaldi M et al (2010) Detection of terrestrial gamma ray flashes up to 40 MeV by the AGILE satellite. J Geophys Res. Google Scholar
  11. Marisaldi M et al (2014) Properties of terrestrial gamma ray flashes detected by AGILE MCAL below 30 MeV. J Geophys Res Sp Phys. Google Scholar
  12. Marisaldi M et al (2015) Enhanced detection of terrestrial gamma ray flashes by AGILE. Geophys Res Lett. Google Scholar
  13. Østgaard N et al (2008) Production altitude and time delays of the terrestrial gamma flashes: revisiting the burst and transient source experiment spectra. J Geophys Res 113:A02307. CrossRefGoogle Scholar
  14. Rodger CJ et al (2009) Growing detection efficiency of the World Wide Lightning Location Network. AIP Conf Proc 1118:1520. Google Scholar
  15. Smith DM et al (2005) Terrestrial gamma-ray flashes observed up to 20 MeV. Science 307:10851088. CrossRefGoogle Scholar
  16. Splitt ME et al (2010) Thunderstorm characteristics associated with RHESSI identified terrestrial gamma ray flashes. J Geophys Res 115:A00E38. CrossRefGoogle Scholar
  17. Stanley MA et al (2006) A link between terrestrial gamma ray flashes and intracloud lightning discharges. Geophys Res Lett 33(6):L06803. CrossRefGoogle Scholar
  18. Tavani M et al (2009) The AGILE mission. Astron Astrophys 502:9951013. CrossRefGoogle Scholar
  19. Williams E et al (2006) Lightning flashes conducive to the production and escape of gamma radiation to space. J Geophys Res 111:D16209. CrossRefGoogle Scholar

Copyright information

© Accademia Nazionale dei Lincei 2019

Authors and Affiliations

  1. 1.Universita degli Studi di FerraraFerraraItaly
  2. 2.CNR-ISACRomeItaly
  3. 3.Università degli studi di BolognaBolognaItaly
  4. 4.UiBUergenNorway
  5. 5.INAF-RomeRomeItaly

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