Characterising Uranus’ Ionisation and Conductivity Profile

Uranus is an Ice Giant planet, a class of large, cold planets characterized by thick atmospheres and the absence of a well-defined solid surface. Hence, atmospheric processes are fundamental to understanding the planet’s physical and chemical environment. Atmospheric ionisation on Earth is driven by solar radiation and energetic particles, radioactive gases and Galactic Cosmic Rays (GCRs) [1].  GCR-induced ionisation is believed to be dominant on Uranus due to its distance from the Sun. In this work, we model the GCR air showers using CORSIKA8 Monte Carlo simulations [2] and calculate the vertical ionisation rate. We capture the variation of ionisation rates with geomagnetic latitude in a novel global map and, for the first time, present a quantitative comparison with ionospheric ionisation rates derived from parameters adopted from the literature. The results show GCR-induced ionisation in the lower stratosphere (peaking at ~104 Pa) to be around two orders of magnitude larger than ionospheric ionisation (