GEOPHYSICAL RESEARCH LETTERS, VOL. 29, NO. 3, 10.1029/2001GL013992, 2002
Temporal and spectral properties of gamma-ray flashes
Department of Engineering Physics, Tsinghua University,
Beijing, China
Institute of High Energy Physics, Chinese Academy of Sciences,
Beijing, China
Physics Department and Astrophysics Center, Tsinghua University,
Beijing, China
Institute of High Energy Physics, Chinese Academy of Sciences,
Beijing, China
Abstract
[1] The temporal and spectral properties of terrestrial gamma-ray flashes (TGFs) are studied. The delay of low energy photons relative to high energy ones in the 
-ray variations of the TGFs with high signal to noise ratio has been revealed by an approach of correlation analysis in the time domain on different time scales. The temporal structures of the TGFs in high energy band are usually narrower than that in low energy band. The spectral hardness has a general trend of decreasing with time in a flash. The observed temporal and spectral characteristics give constraints and valuable hints on the flash production mechanism.
Received 27 August 2001; revised 28 November 2001; accepted 3 January 2002; published 15 February 2002.
Index Terms: 2423 Ionosphere: Ionization mechanisms; 3324 Meteorology and Atmospheric Dynamics: Lightning; 7554 Solar Physics, Astrophysics, and Astronomy: X rays, gamma rays, and neutrinos; 7853 Space Plasma Physics: Spacecraft/atmosphere interactions.
Citation: Temporal and spectral properties of gamma-ray flashes, Geophys. Res. Lett., 29(3), 10.1029/2001GL013992, 2002.