The global electric circuit and climate processes

Abstract:

Earth’s Global Electric Circuit (GEC) has been investigated for almost a century, but the links between the GEC and global climate processes are still very much quantitatively unexplored. Recent observational and theoretical work suggests that the GEC conduction current modifies the behaviour of cloud droplets in non thunderstorm clouds, potentially changing large scale cloud properties on a global scale, and even rainfall. Understanding such processes requires detailed information on what drives the GEC conduction current, both in terms of internal (e.g. thunderstorm, electrified shower cloud and convective generators), and external (galactic cosmic ray, and solar cosmic ray) influences, which requires improved monitoring of the GEC and cloud related variables.

This work presents a summary of recent advances in observational techniques, atmospheric electricity instrumentation, and the establishment of a global network for fair weather atmospheric electricity measurements, which is making it possible to investigate the detail of GEC and global climate links. Research will be presented on (1) the GloCAEM (Global Coordination of Atmospheric Electricity) network, which has brought together electric field data from four continents to attempt to monitor the GEC more continuously. This also includes the establishment of two additional high latitude sites (in the Arctic and Antarctic), which show very close agreement with the global Carnegie oscillation. (2) Advances in understanding on how the GEC conduction current modulates non thunderstorm cloud properties, and therefore Earth’s radiative balance. (3) Understanding the role of convective generators in the planetary boundary layer (particularly in arid and snow covered regions) and their potential contribution to the GEC.