The Terrestrial Gamma-ray Flashes (TGF) to lightning ratio, computed over the 3 tropical chimneys, presents a paradox: African thunderstorms produce the most lightning but yield the lowest fraction of TGF when compared to American and Southeast Asian thunderclouds. To understand the physical insights into this asymmetry, TRMM Precipitation Radar measurements are used to depict the vertical precipitation structure of the observed thunderstorms in the 3 regions and the thunderstorms during TGF occurrences detected by AGILE, Fermi-GBM and RHESSI sensors. African thunderstorms are taller, smaller and have higher concentration of dense ice particles above the freezing level. TGF thunderstorms are taller and less intense (0.5-2dBZ), besides presenting similar radar reflectivity decay with height independent of the region. In addition, these storms show thicker electrical charge layers separated by 4.7-5.2 km and also a positive charge fraction reduction between -20 o C and -40 o C and enhancement above -50 o C when compared to the overall thunderstorms.

The Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS) provides optical radiances and images of lightning flashes in several spectral bands. This work presents a lightning flash simultaneously observed from space by ASIM, the Geostationary Lightning Mapper (GLM) and the Lightning Imaging Sensor on the International Space Station (ISS-LIS); and from ground by the Colombia Lightning Mapping Array (Colombia-LMA). Volumetric weather radar provides reflectivity data to help to interpret the effects of the cloud particles on the observed optical features. We found that surges in radiance in the band at 777.4 nm, appear to be related mostly with lightning processes involving currents as well with branching of lightning leaders with new leader development. In cloud areas with reflectivity <18 dBZ above the lightning leader channels at altitudes >7 km, these have been imaged by ASIM and GLM. But in the region with reflectivity <23 dBZ, despite its lower cloud tops and similar altitudes of lightning channels, these have been almost undetectable. The estimated relative optical depth results consistent with the observed optical features at the different locations of the flash. Despite of the effects of the cloud particles and the altitude of the lightning channels on the attenuation of the luminosity, the luminosity of the lightning channels due to different processes is fundamental for the imaging of lightning from space.