Recent progress on the global electrical circuit

Research work on the global electrical circuit (GEC) is reviewed, with an emphasis on the period since the last International Conference on Atmospheric Electricity (ICAE) in Beijing, China in 2007. This review was presented initially (in more abbreviated form) at the ICAE in Rio de Janeiro, Brazil in August 2011. The topics selected for discussion in the context of the GEC are electrified shower clouds (Section 2), mesoscale convective systems (Section 3), measurement of the DC electric field (Section 4), electrical quantities and energy (Section 5), convective turbulent currents (Section 6), lightning (Section 7), the Earth–ionosphere waveguide (Section 8), variations on the ENSO time scale (Section 9), model simulations of short-term variability and long-term trend of the GEC (Section 10), the weekly cycle in aerosol and lightning (Section 11), conductivity perturbations and the effects of enhanced radioactivity (Section 12), cosmic ray-mediated cloud microphysics on the 11-year solar cycle (Section 13), the impact of a gamma ray flare (Section 14), and planetary electrification (Section 15).