Toward a standardized platform for modeling electrical discharges in planetary atmospheres

Toward a standardized platform for modeling electrical discharges in planetary atmospheres

Authors: J. A. Riousset and A. B. Esparza

Stochastic models of electric discharges have a long and distinguished history (e.g., Niemeyer et al., 1984, doi: 10.1103/PhysRevLett.52.1033; Petrov and Petrova, 1999, doi: 10.1134/1.1259327; Pasko et al., 2000, doi: 10.1029/1999GL010749; Mansell et al., 2002, doi: 10.1029/2000JD000244; Riousset et al., 2007, doi: 10.1029/2006JD007621; Carlson, 2025, Private Communication). They have successfully modeled streamer and leader-based discharges, including positive and negative cloud-to-ground discharges, intracloud lightning, bolt-from-the-blue events, blue starters, blue jets, gigantic jets, and sprites. They demonstrated a remarkable adaptability and accuracy. The FRActal Model of Electrical Discharge (FraMED) framework builds on this versatility to offer a platform for modeling electrostatic discharge. It is capable of simulating both leader and streamer channels with minimal changes. Recent updates allowed one-way coupling and interfacing with atmospheric models (EPIC or GRAM) to study extraterrestrial discharges. Yet, despite numerous improvements and developments, most, if not all, fractal models suffered from the absence of a timescale, due to their intrinsically iterative nature. Here we propose a self-consistent implementation of time estimates based on channel velocity. This backward-compatible approach also leads to an approximation of the current in the discharge channel. The results are consistent with literature data on positive and negative cloud-to-ground discharges and intracloud ones. This can ultimately inform instrument designs for lightning and Transient Luminous Events (TLEs) on Earth and beyond.