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[1] Modeling studies indicate that double-headed streamers originating from single electron avalanches in lightning-driven quasi-static electric fields at mesospheric altitudes accelerate and expand, reaching transverse scales from tens to a few hundreds of meters and propagation speeds up to one tenth of the speed of light, in good agreement with recent(More)
[1] Streamers are thin filamentary plasmas that can initiate spark discharges in relatively short (several centimeters) gaps at near ground pressures and are also known to act as the building blocks of streamer zones of lightning leaders. These streamers at ground pressure, after 1/N scaling with atmospheric air density N, appear to be fully analogous to(More)
A novel immersed boundary velocity correction–lattice Boltzmann method is presented and validated in this work by its application to simulate the two-dimensional flow over a circular cylinder. The present approach is inspired from the conventional immersed boundary method (IBM). In the conventional IBM, the effect of rigid body on the surrounding flow is(More)
[1] The time dependent optical emission model developed by Liu and Pasko (2004) is applied to studies of far-UV emissions of sprite streamers due to N 2 Lyman-Birge-Hopfield (LBH) band system. Modeling results indicate that the LBH emissions of sprite streamers at 70 km are generally stronger by up to a factor of 10 than those from the first negative band(More)
[1] A two-dimensional fluid model with multiple charged species is developed for simulating the ionospheric responses to the lightning quasi-static electric (QE) field. In addition to electrons, the model takes into account four symbolic ion species and O À ions that are considered separately to investigate the role of the fast electron detachment process(More)
[1] In this study, we compare sprite streamer modeling results with Imager of Sprites and Upper Atmospheric Lightning (ISUAL) spectrophotometric data for several sprite events. The model positive streamers are simulated for two representative magnitudes of the quasi-electrostatic field produced by cloud-to-ground lightning discharges, reflecting conditions(More)
Recent advances in development of photoionization models in air based on radiative transfer and Helmholtz equations open new perspectives for efficient solution of nonthermal gas discharge problems involving complex geometries. Many practical applications require accurate modeling of streamer discharges developing in weak electric fields, in which the(More)
This Letter reports a modeling study on the formation of streamer discharges from an isolated ionization column under subbreakdown condition. Numerical simulations show that positive streamers are able to form from the tip of an ionization column in a uniform applied electric field well below the breakdown threshold field. However, even when the applied(More)