Influence of topography on the atmospheric thermal tides and rotational evolution of Venus

¹ Nantes Université, Univ Angers, Le Mans Université, CNRS, Laboratoire de Planétologie et Géosciences, LPG UMR 6112, 44000 Nantes, France
² LIRA, Observatoire de Paris, Université PSL, Sorbonne Université, Université Paris Cité, CY Cergy Paris Université, CNRS, Meudon, France
³ Laboratoire de Météorologie Dynamique, Sorbonne Université, ENS, PSL Research University, École Polytechnique, Institut Polytechnique de Paris, CNRS, Paris, France

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 26 February 2026
Accepted: 10 June 2026

Abstract

Context. Venus’ rotation is the slowest of all the planets in the Solar System and is in the retrograde direction. Such a rotational state results directly from several tidal effects that impact both the atmosphere and the solid part of the planet. To fully characterize the rotational dynamics and evolution of Venus, it is therefore mandatory to have a comprehensive understanding of the various factors that influence the different tidal effects and in particular the atmospheric thermal tides.

Aims. In this context, this work investigates how the distribution of the topography, which likely changed during Venus’ history through resurfacing events or true polar wander (TPW), affect the atmospheric thermal tides and, consequently, the rotational state of the planet. Moreover, we examine how the presence of topography affects the dependence of the atmospheric thermal torque on the rotation period and how it may have influenced the global evolution of the rotation.

Methods. Using the Venus Planetary Climate Model (V-PCM), we first focused on characterizing the influence of the topography on atmospheric thermal tides. For that purpose, we performed a series of global atmospheric dynamics simulations exploring various configurations of the topography and computed the atmospheric thermal torques from the surface pressure anomalies. Second, we updated an empirical law that links the atmospheric thermal torque to the forcing frequency by evaluating the strength of the atmospheric tides at different rotation periods using V-PCM simulations.

Results. Our results first highlight the link between topography and thermal tides, showing that the variations in the atmospheric thermal torque over a solar day are mainly controlled by the large-scale near-equatorial topography. Moreover, we show that changes in the topography not only introduce strong diurnal variations in the torque but also change its daily average value, and therefore impact the whole rotational evolution of the planet.

Conclusions. This study highlights that the rotational state and evolution of Venus, as well as other planets and exoplanets, therefore depend on the variations in the topography and that modeling it without including this topographic effect can introduce significant uncertainties.