Arctic lightning during solar wind disturbance
En palabras de los autores
Abstract The mechanisms modulating lightning are not entirely understood. While electric fields within thunderclouds are insufficient to initiate lightning, solar-wind activity has been proposed as one of the possible external drivers, operating via energetic particles and modifications to the global atmospheric electric circuit. However, solar-wind impacts on lightning activity remain underexplored, particularly at high latitudes. Here, we analyze statistical relationships between solar-wind activity and lightning over Fennoscandia. During solar cycle 23, annual lightning activity at 62–67°N correlates significantly with energetic proton fluxes and, at 65–67°N, with high-speed solar wind streams. However, a short-term analysis reveals weaker relationships. An event-based analysis demonstrates that within specific northern latitude bands, high-speed streams significantly double the probability of extreme-lightning days when suitable convective cloud conditions are already established. These findings demonstrate that solar-wind influence on lightning activity is not driven by a single mechanism, but is a sporadic, regionally structured phenomenon strictly constrained by local meteorological conditions and, surprisingly, emerges only on long timescales.
Apareció: jueves, 24 de septiembre. Communications Earth & Environment. Revista con revisión por pares.