arXiv subjects

Aleš Berkopec

Publications and source records attributed to Aleš Berkopec.

3 recordsLinked to original sources

arXiv2020

Thunder-cell as Source of Energetic Protons

In this article we present the following hypothesis: thunder-cell ejects highly energetic protons, each of which creates a tree-structure of weakly ionized trajectories that can develop into a lightning channel. The tree-structure and the channel have the same geometry so the mean free path of a proton corresponds to the average length of the channel between two successive nodes (branching points). We show this length is around 660 m in lower Earth atmosphere. Effects of Coulomb interaction and various outcomes of proton-nucleus reaction are taken into account. A prediction of CG/CC ratio that follows agrees well with the available data, but only measurements of lightning geometry can reveal whether the hypothesis is any closer to the correct explanation of the phenomenon.

physics.ao-ph↗

arXiv2016

About Geometry and Initial Phase of Cloud-to-Ground Lightning

Cloud-to-ground lightning is the most common among atmospheric discharges. Since electric fields in the vicinity of a thunder-cloud do not exceed 250 kV/m the physical process that triggers the lightning remains unexplained. [1, 2, 3] Recent measurements established a weak correlation between solar wind and incidence of lightning. [4] Here we show, that if an ionized path created by cosmic rays provides a trigger, the distribution of lengths between two successive forking points in a lightning channel (internodes) closely resembles the exponential distribution with average length between 415 m and 510 m. The results, if confirmed, imply that a thunder-cell may be an additional source of fast elementary particles that initiate lightning process.

physics.ao-ph↗

arXiv2014

Cantilever Beam Equation for Almost Arbitrary Deflections: Derivation and Worked Examples

We derived a non-linear 4th-order ordinary differential equation the solutions of which lead to the exact shapes of the cantilever beam. The result of the equation in a non-dimensional form was found to depend on two parameters only: the angle of the beam at the fixed end, and the parameter encompassing the material characteristics and geometry of the beam. The parameter space was explored in detail and the results were used to suggest the areas in which they could be applied.

physics.class-ph↗