Volatile Element Cycles on Venus: Implications for the Evolution of Venus´ Greenhouse-Dominated Atmosphere

Introduction

Venus is similar to Earth in terms of density, size, and composition. Yet both bodies evolved so dramatically differently that Venus now has an uninhabitable, runaway greenhouse atmosphere in contrast to Earth's favorable habitable conditions. Despite alarming parallels with CO2-driven global warming on Earth, the origin and evolution of Venus' runaway greenhouse atmosphere remain poorly understood.

Current Challenges

Problematically, current models fail to incorporate the important effects of volcanic degassing and atmosphere-surface interaction throughout Venus' history. Due to Venus’ CO2-rich atmosphere, surface pressures are 90 times greater than on Earth.

Volcanic Activity

Volcanoes on Venus will degas under very different conditions, yielding different volcanic gas compositions and gas fluxes to the atmosphere. Constraints on volatility and the contribution of magmatic volatiles to the composition of Venus' atmosphere are pivotal for understanding the extent and timing of volcanic activity on Venus, especially in light of upcoming Venus exploration missions.

Atmospheric Interactions

Interaction between Venus’ atmosphere, volcanic gases, and surface likely plays a key role in determining volatile fluxes but is poorly understood at conditions relevant for Venus’ surface. The critical lack of such challenging experiments precludes a detailed assessment of the Venusian volatile cycle and atmospheric evolution.

Research Objectives

I will quantify the past and current interior-to-atmosphere volatile element flux on Venus. In a highly multi-disciplinary approach, I will perform:

1. Pioneering, high P-T experiments mimicking magma degassing on Venus and atmosphere-gas-rock interactions.
2. State-of-the-art (in situ) analyses of gas speciation and reaction rates.
3. Integration of these results in numerical models to obtain quantitative volatile fluxes for Venus.

This work allows for a rigorous reassessment of Venus’ interior and atmospheric evolution and will provide a solid framework for future exploration of Venus.