X-rays have been observed in natural downward cloud-to-ground lightning for over 20 years and in rocket-triggered lightning for slightly less. In both cases, this energetic radiation has been detected during the stepped and dart leader phases of downward n ...
The multipole expansion, a ubiquitous tool in a variety of physical problems, can be formulated in spherical and Cartesian coordinates. By constructing an explicit map linking both formulations in isotropic media, we discover a lack of equivalence between ...
This study presents the first observation of a mixed mode (MM) of charge transfer during an upward positive flash, which was initiated from the Säntis Tower in Switzerland. High‐speed camera footage, along with current and electric field measurements, reve ...