Taking account of topography when calculating the resistance of the global atmospheric conductor

The role of topography in the formation of the global electric circuit is analyzed. The topography of the Earth’s surface is determined using the GLOBE database providing data on height of the Earth’s surface above mean sea level in geodetic coordinates with spatial resolution of 30 angular seconds. The atmosphere is considered as a global conductor between the Earth’s surface and the ionosphere simulated as ideal conductors. Empirical models of air conductivity are used. To simplify the description of large-scale phenomena, the model is reduced to one-dimensional simulation of vertical columns of air. The inclusion of topography is shown to reduce the resistance of the atmosphere by 10 % and to reduce the local resistance above high mountains several times. Note that taking topography into account is also important in more general models of electrical conductivity of the atmosphere.