Abstract/Summary

Atmospheric electricity has important impacts across a range of disciplines. On Earth, lightning influences atmospheric chemistry, with related chemical processes considered important to the origins of life. Atmospheric electricity can affect other atmospheric processes, such as the stability, growth, and disintegration of cloud droplets. Previous investigations of atmospheric electricity on Venus have primarily focused on detections of lightning. From comparison with Earth, there are many other aspects of atmospheric electricity which require understanding, such as the effects of cosmic ray ionisation and electric charges on the clouds of Venus. Through an investigation of a point discharge sensor on Earth, it was discovered that the operation of the sensor depended on both electrostatic and electrodynamic terms - interpreted as both free and displacement currents being detected. Knowledge of these sensors was applied to an investigation of the electrical discharges recorded by the Venera 13 & 14 spacecraft. It was found, via electrical modelling of Venus’ atmosphere, that the best reproduction of the Venera data required both low-atmosphere haze layers and a global atmospheric electric circuit. Estimates were made for the strength of such a circuit, with the required conduction currents between -1 and 7 fA/m2 . Finally, space weather effects were investigated at Venus, with both solar energetic particle events and heliospheric current sheet crossings detected at the planet. It was found that space weather events associated with coronal mass ejections had a noticeable impact on the atmosphere of Venus, causing significant increases in the albedo. These are some of the first results demonstrating that there is a space weather effect in Venus’ atmosphere. These results suggest electrical processes have effects in Venus’ atmosphere. Future investigations are required to identify any charge separation processes which could produce a global electric circuit, and to identify the mechanisms linking space weather variations to atmospheric processes.