Otal present remains zero above the height z. Precisely the same technique will perform in the event the speed of your current pulse is changed at height z. Within this case, we’ve got to initiate two present pulses at height z: 1 moving upwards together with the reduced speed and also the other moving upwards together with the initial speed but with opposite polarity. This shows that any arbitrary spatial and temporal variation in the return stroke existing could be described as a sum of transmission line-type currents possessing different speeds, polarity, and present amplitude initiated at unique places and at different instances. This makes it doable to extend the results obtained here to any arbitrary current and charge distributions. 6. Conclusions Within the literature, there are actually four techniques to calculate the electromagnetic fields from lightning. These four approaches lead to four expressions for the electromagnetic fields. We have shown that the field elements extracted utilizing these four strategies may be lowered to one single field expression with the total field separated into field terms arising from accelerating charges, uniformly moving charges, and stationary charges. We conclude that the non-uniqueness of the different field terms arising from diverse approaches is only an apparent function.Atmosphere 2021, 12,9 ofAs lengthy because the use on the distinctive techniques for the field calculation is concerned, one can adopt the one particular that suits greatest the viewed as application (when it comes to ease of application, computation time considerations, etc.), considering the fact that all of them deliver exactly the same benefits for the total electromagnetic fields. Alternatively, if the objective would be to deliver insight into the underlying physical processes, the accelerating, uniformly moving, and stationary charge field elements are advisable. Indeed, these components are straight related towards the physical processes generating the field, and for that reason, they may be uniquely defined inside a provided reference frame.Author Contributions: V.C. and G.C. conceived the idea and created the Glycodeoxycholic Acid-d4 Autophagy mathematics and also the computer software program. V.C., G.C., F.R. and M.R. contributed equally to the analysis and in writing the paper. All authors have read and agreed towards the published version on the manuscript. Funding: This operate was supported partly by the fund from the B. John F. and Svea alpha-D-glucose Description Andersson donation at Uppsala University. V.C. thanks Mats Leijon for placing the study facilities on the division of electricity at V.C.’s disposal. Conflicts of Interest: The authors declare no conflict of interest.Appendix A. Similarity of Field Expressions Provided by Equations (7) and (9a ) The aim of this appendix is always to show analytically the equivalence among the field equations pertinent to the transmission line model derived utilizing the continuity equation along with the field equations derived working with the constantly moving charge procedure. Let us start with the field equations pertinent to the continuity equation procedure. They are given by Equation (7) as 1 Ez (t) = – 2L1 z i (t ) dz- 2 0 r3 vL1 z i (t ) dz- 2 0 cr2 v tL1 i (t ) dz c2 r t(A1)with t = t – z/v – z c+d . Let us combine the final two terms of your above equation to acquire 1 Ez (t) = – 2L1 z i (t ) dz- 3 v 2 0 rLcv(zz2 + d2 c1 z + two) 1/2 +d c2 ( z2 + d2 )i (t ) dz t(A2)Now, thinking about t = t – z/v – t = zwe find that (A3)1 z – – two + d2 v c zLet us rewrite the expression for the electric field as follows 1 Ez (t) = – 2Lz i (t ) 1 dz- three v 2 0 rL 0 LLcv(zz 1 + 2) 1/2 +d c2 ( z2 + d2 )i (t ) dz t1 – 2.