Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.
AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.
A recent study pointed out that macroscopic dark matter (macros) traversing through the Earth’s atmosphere can give rise to hot and ionized channels similar to those associated with lightning leaders. The authors of the study investigated the possibility t ...
Dealing with lightning performance computation, researchers usually consider only negative downward first return strokes and the relevant channel-base peak current distribution. The aim of this article is to account for the lightning flash mechanism, which ...
Currently, plenty of sensitive electronic devices are installed in secondary circuits in substations and power plants. Electronic devices may malfunction and become damaged owing to electromagnetic disturbances caused mainly by lightning surges. To protect ...
Lightning physics is highly multidisciplinary, involving areas such as plasma physics, electrical engineering, meteorology, thermodynamics and particle physics. Upward lightning is a special type of lightning initiated from tall structures that has attract ...
Upward lightning is the dominant type of lightning discharge to tall structures. It has been observed that a significant number of these upward flashes are initiated by nearby lightning activity. The aim of this study is to estimate the incidence of upward ...
This article provides the implementation procedure, the validation, and some considerations on the computational efforts of the analytical expressions developed for the lightning electromagnetic fields presented in the companion paper. The validation is pr ...
We report the observation of three negative upward flashes recorded by a high-speed camera at the Säntis Tower during the Summer of 2019. The camera was operating at 10,000 fps and an exposure time of 99 μs. Simultaneous measurements of the lightning curre ...
The article provides a new channel-based current function, which aims at faithfully reproducing the salient parameters of lightning currents. All the model parameters can be set in a fully analytical way, guaranteeing the possibility of changing them (acco ...
The article provides analytical expressions for the electromagnetic fields generated by a lightning return stroke characterized by a channel-base current with arbitrary time waveform, in presence of either a perfectly conducting or a lossy ground, assuming ...
Lightning is formed in the atmosphere through the combination of intricate dynamic and microphysical processes. Mainly due to this complexity, attempts to solve the important problem of lightning prediction have generally failed to yield accurate results. ...
