Solar storms strip Venus of atmosphere faster when hotter, study shows
New simulations reveal that extreme solar wind temperatures—not just pressure—accelerate the escape of ions from Venus's atmosphere during coronal mass ejections. The finding could reshape models of planetary habitability and inform spacecraft design for deep space missions near the sun.
Originaltitel: Venusian ion escape under extreme conditions: A dynamic pressure and temperature simulation study
<p><em>Context</em>. 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).</p><p><em>Aims</em>. 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.</p><p><em>Methods</em>. 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<sup>+</sup> and O<sup>+</sup> ion escape was then examined and compared for different escape channels.</p><p><em>Results</em>. In both dynamic pressure enhancement cases, we find that there is no clear dependence of the O<sup>+</sup> 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<sup>+</sup> and O<sup>+</sup> 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.</p>