Temporal and radiometric statistics on lightning flashes observed from space with the ISUAL spectrophotometer

摘要: The Imager of Sprites and Upper Atmospheric Lightning (ISUAL) on the FORMOSAT-2 satellite was launched in 2004 records transient luminous events (TLEs). ISUAL is an instrument composed imager a multichannel spectrophotometer which able to measure brightness from far ultraviolet near infrared for TLEs lightning flashes. Several types have been identified, classified, documented between 2014. However, no statistical analyses already realized. In this paper, we focus flashes did not induce TLEs. Statistics about or temporal dynamic are presented fitted waveforms infrared, after having corrected atmospheric effects each channels. We demonstrate that lightning/satellite distance altitude need be taken into account. channel could modeled as exponential pulsed function shape explained by photon propagation cloud. median values at 777.4 nm 1.63 × 10−6 W m−2 maximum brightness, 5.85 × 104 J total energy source, 414 µs full width half maximum, 620 µs quarter 170 µs risetime. Results compared with previous experiments performed visible near-infrared domains. variables shorter than UV waveforms.