Abstract A numerical model based on the finite-difference time-domain (FDTD) method is developed for calculating discharge currents and fields produced due air ionization between two electrodes. Electric conductivity σ of the ionized channel between two electrodes is calculated using non-linear equations, i.e., σ is obtained using functions of time. The functions for calculating σ are adapted and proposed in this work for each stage of the plasma formation and disrupting processes. The proposed numerical model is validated by making comparisons among the obtained FDTD results and experimental data published in literature. In order to perform the validation procedures, an experimental setup from literature is numerically reproduced using the proposed FDTD methodology.

Abstract The Amazon region has high lightning occurrence rates, with many lightning hot spots. Different rivers cross the Amazon rainforests and the people that live there use these rivers as roads to go from one place to another. Every year, lightning deaths are reported in the Brazilian Amazon region. In 2018, a lightning discharge struck a small riverboat, which killed 4 people and injured 5 in the North region of Brazil. In this study, we investigate lightning fatalities in Amazon rivers and compute electric field distribution in a small riverboat due to a lightning strike using the finite-difference time-domain (FDTD) method. The results show that the electric field produced inside the boat is large enough to cause air breakdown. Additionally, we propose a cost-effective method to improve lightning safety for people that use small boats in the Amazon region.