Thermal tides in neutrally stratified atmospheres: Revisiting the Earth’s Precambrian rotational equilibrium
| dc.contributor.author | Farhat, Mohammad | |
| dc.contributor.author | Auclair-Desrotour, Pierre | |
| dc.contributor.author | Boué, Gwenaël | |
| dc.contributor.author | Deitrick, Russell | |
| dc.contributor.author | Laskar, Jacques | |
| dc.date.accessioned | 2024-07-08T15:18:57Z | |
| dc.date.available | 2024-07-08T15:18:57Z | |
| dc.date.issued | 2024 | |
| dc.description | The authors are thankful to the referee, Dorian Abbot, for insightful comments which helped improve the manuscript considerably. M.F. expresses his gratitude to Kevin Heng for his hospitality at the LMU Munich Observatory where part of this work was completed. | |
| dc.description.abstract | Rotational dynamics of the Earth, over geological timescales, have profoundly affected local and global climatic evolution, probably contributing to the evolution of life. To better retrieve the Earth’s rotational history, and motivated by the published hypothesis of a stabilized length of day during the Precambrian, we examined the effect of thermal tides on the evolution of planetary rotational motion. The hypothesized scenario is contingent upon encountering a resonance in atmospheric Lamb waves, whereby an amplified thermotidal torque cancels out the opposing torque generated by the oceans and solid interior, driving the Earth into rotational equilibrium. With this scenario in mind, we constructed an ab initio model of thermal tides on rocky planets describing a neutrally stratified atmosphere. The model takes into account dissipative processes with Newtonian cooling and diffusive processes in the planetary boundary layer. We retrieved, from this model, a closed-form solution for the frequency-dependent tidal torque, which captures the main spectral features previously computed using 3D general circulation models. In particular, under longwave heating, diffusive processes near the surface and the delayed thermal response of the ground prove to be responsible for attenuating, and possibly annihilating, the accelerating effect of the thermotidal torque at the resonance. When applied to the Earth, our model prediction suggests the occurrence of the Lamb resonance in the Phanerozoic, but with an amplitude that is insufficient for the rotational equilibrium. Interestingly, though our study was motivated by the Earth’s history, the generic tidal solution can be straightforwardly and efficiently applied in exoplanetary settings. | |
| dc.description.reviewstatus | Reviewed | |
| dc.description.scholarlevel | Faculty | |
| dc.description.sponsorship | This work has been supported by the French Agence Nationale de la Recherche (AstroMeso ANR-19-CE31-0002-01) and by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Advanced Grant AstroGeo-885250). This work was granted access to the HPC resources of MesoPSL financed by the Region Île-de-France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche. | |
| dc.identifier.citation | Farhat, M., Auclair-Desrotour, P., Boué, G., Deitrick, R., & Laskar, J. (2024). Thermal tides in neutrally stratified atmospheres: Revisiting the Earth’s Precambrian rotational equilibrium. Astronomy & Astrophysics. https://doi.org/10.1051/0004-6361/202348625 | |
| dc.identifier.uri | https://doi.org/10.1051/0004-6361/202348625 | |
| dc.identifier.uri | https://hdl.handle.net/1828/16725 | |
| dc.language.iso | en | |
| dc.publisher | Astronomy & Astrophysics | |
| dc.rights | Attribution 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | |
| dc.subject.department | School of Earth and Ocean Sciences | |
| dc.title | Thermal tides in neutrally stratified atmospheres: Revisiting the Earth’s Precambrian rotational equilibrium | |
| dc.type | Article |