Venusian ion escape under extreme conditions: A dynamic pressure and temperature simulation study

¹ Space and Plasma Physics Division, KTH Royal Institute of Technology, Stockholm, Sweden
² Swedish Institute of Space Physics, Uppsala, Sweden
³ Laboratoire de Physique des Plasmas (LPP), Paris, France
⁴ IRAP, CNRS-UPS-CNES, Université de Toulouse, Toulouse, France
⁵ ISAS/JAXA, Sagamihara, Japan
⁶ LATMOS/IPSL, UVSQ Université Paris-Saclay, UPMC University Paris CNRS, Guyancourt, France
⁷ Thales, Toulouse, France
⁸ Institut Supérieur de l’Aéronautique et de l’Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France

^★ Corresponding author; mcka@kth.se

Received: 23 January 2024
Accepted: 18 September 2024

Abstract

Context. We investigated the response of the Venusian atmospheric ion escape under the effect of interplanetary coronal mass ejections (ICMEs) using the Latmos Hybrid Simulation (LatHyS).

Aims. In particular, we focused on the influence of extreme ICME dynamic pressures and temperatures, with the temperature being a parameter that has not been extensively studied in the past.

Methods. Simulations were performed for two different dynamic pressures and three different temperatures. For the case of the dynamic pressure simulations, a density and a velocity enhancement event were studied separately. The H⁺ and O⁺ ion escape was then examined and compared for different escape channels.

Results. In both dynamic pressure enhancement cases, we find that there is no clear dependence of the O⁺ ion escape on the dynamic pressure, which is consistent with observations. On the other hand, the temperature of the incoming solar wind positively influences the H⁺ and O⁺ ion escape. This is attributed in part to the enhanced gyroradius of the particles, which allows them to penetrate deeper into the planet’s atmosphere.