At this moment we are waiting for more chances to observe sprites or elves – any Transient Luminous Events (TLEs). Having already observed some one can think about using them with other measurements to extend the TLEs-related scientific studies. One of the important possibilities is to compare the optical observations with measurements of electromagnetic field in the Ultra Low Frequency range and Extremely Low Frequency range (0.003 Hz – 3000 Hz).
Thunderstorm discharges generate electromagnetic radiation over a wide spectrum, with the maximum in the ULF/ELF range. It can be observed in electromagnetically quiet places on the globe. The large discharges, that usually accompany sprites (parent-lightnings), produce electromagnetic signals, usually of high amplitude and specific shape, and cause characteristic ULF/ELF events. This is also believed to be the case for some sprites and elves. Thus the simultaneous observations of both would be very useful. By use of these measurements we can learn more about:
- What are the connections between the sources and the produced electromagnetic signals?
- How these signals propagate in the environment?
Besides the CAL research groups, which are especially involved in TLEs research, other scientific groups have already become interested in contribution with their measurements and efforts to study the related phenomena in the ULF, ELF, VLF ranges and beyond.
This web site provides more links and details on some electromagnetic ULF/ELF phenomena, measurements, and the role of ULF/ELF measurements in TLEs-related studies.