Environmental conditions

Global distribution of lightning in flashes/km2/year (Christian et al., 2003)

Environmental conditions
Questions to be addressed	On-board instruments	Studies to be performed
▪ Point out lightning activity conditions (QE thundercloud fields included) for the generation of TLEs or/and TGFs; ▪ Identify parent lightning flashes and resolve ambiguities with time delays; ▪ Identify potential electromagnetic signatures of “hidden processes” involved in the generation of TLEs or/and of TGFs.	▪ Cameras and photometers ▪ X- and gamma-rays; ▪ Relativistic and energetic electrons ▪ Wave field measurements from DC to 30 MHz ▪ 0+ whistler detector.	▪ Correlate measurements of TLEs and TGFs with lightning activity determined at ground and to QE fields derived from ground-based and satellite-based measurements; ▪ Remove ambiguities between ground-based measurements of lighting flashes and 0+ whistler measurements; ▪ Look for EM signatures of “hidden processes" from DC to 30 MHz.
▪ Investigate possible effects of large scale movements of the thermal plasma on the altitude sources.	▪ Same as above; ▪ Ion probe.	▪ Investigate variations of TLEs and TGFs as regards to large scale movement of thermal plasma.
▪ Investigate possible correlations with bursts of electrons, extensive atmospheric showers, cosmic radiation of lower energy, other potential triggering factors (micrometeorites, volcanoes, etc).	▪ Same as above.	▪ Correlate satellite based-measurements with ground-based data bases of extensive atmospheric showers, volcanoes, micrometeorites, etc.