On the energetics of a tidally oscillating convective flow

Monthly Notices of the Royal Astronomical Society Oxford University Press 525:1 (2023) 508-526


This paper examines the energetics of a convective flow subject to an oscillation with a period $t_{\rm osc}$ much smaller than the convective time-scale $t_{\rm conv}$, allowing for compressibility and uniform rotation. We show that the energy of the oscillation is exchanged with the kinetic energy of the convective flow at a rate $D_R$ that couples the Reynolds stress of the oscillation with the convective velocity gradient. For the equilibrium tide and inertial waves, this is the only energy exchange term, whereas for p modes there are also exchanges with the potential and internal energy of the convective flow. Locally, $\left| D_R \right| \sim u^{\prime 2} / t_{\rm conv}$, where $u^{\prime}$ is the oscillating velocity. If $t_{\rm conv} \ll t_{\rm osc}$ and assuming mixing length theory, $\left| D_R \right|$ is $\left( \lambda_{\rm conv} / \lambda_{\rm osc} \right)^2$ smaller, where $\lambda_{\rm conv}$ and $\lambda_{\rm osc}$ are the characteristic scales of convection and the oscillation. Assuming local dissipation, we show that the equilibrium tide lags behind the tidal potential by a phase $\delta(r) \sim r \omega_{\rm osc} / \left( g(r) t_{\rm conv}(r) \right)$, where g is the gravitational acceleration. The equilibrium tide can be described locally as a harmonic oscillator with natural frequency $\left( g/r \right)^{1/2}$ and subject to a damping force $-u^{\prime}/t_{\rm conv}$. Although $\delta(r)$ varies by orders of magnitude through the flow, it is possible to define an average phase shift $\overline{\delta }$ which is in good agreement with observations for Jupiter and some of the moons of Saturn. Finally, $1 / \overline{\delta }$ is shown to be equal to the standard tidal dissipation factor.

Planetary Systems: From Symmetry to Chaos

Chapter in The Language of Symmetry, (2023) 1-11


This chapter first discusses the definitions of disorder and chaos in physics. Then, Professor Terquem explores the dynamics of planetary systems. In particular, she examines how the seemingly chaotic process of planetary formation yields synchronised systems in their orbits. The transition is an excellent example of how a disordered physical system can generally tend to a state of orderedness.

A Spectroscopic Thermometer: Individual Vibrational Band Spectroscopy with the Example of OH in the Atmosphere of WASP-33b



Sam OM Wright, Stevanus KK Nugroho, Matteo Brogi, Neale PP Gibson, Ernst JW de Mooij, Ingo Waldmann, Jonathan Tennyson, Hajime Kawahara, Masayuki Kuzuhara, Teruyuki Hirano, Takayuki Kotani, Yui Kawashima, Kento Masuda, Jayne LL Birkby, Chris AA Watson, Motohide Tamura, Konstanze Zwintz, Hiroki Harakawa, Tomoyuki Kudo, Klaus Hodapp, Shane Jacobson, Mihoko Konishi, Takashi Kurokawa, Jun Nishikawa, Masashi Omiya, Takuma Serizawa, Akitoshi Ueda, Sebastien Vievard, Sergei NN Yurchenko

Carbon monoxide emission lines reveal an inverted atmosphere in the ultra hot Jupiter WASP-33 b consistent with an eastward hot spot



Lennart van Sluijs, Jayne L Birkby, Joshua Lothringer, Elspeth KH Lee, Ian JM Crossfield, Vivien Parmentier, Matteo Brogi, Craig Kulesa, Don McCarthy, David Charbonneau

Chasing rainbows and ocean glints: Inner working angle constraints for the Habitable Worlds Observatory



Sophia R Vaughan, Timothy D Gebhard, Kimberly Bott, Sarah L Casewell, Nicolas B Cowan, David S Doelman, Matthew Kenworthy, Johan Mazoyer, Maxwell A Millar-Blanchaer, Victor JH Trees, Daphne M Stam, Olivier Absil, Lisa Altinier, Pierre Baudoz, Ruslan Belikov, Alexis Bidot, Jayne L Birkby, Markus J Bonse, Bernhard Brandl, Alexis Carlotti, Elodie Choquet, Dirk van Dam, Niyati Desai, Kevin Fogarty, J Fowler, Kyle van Gorkom, Yann Gutierrez, Olivier Guyon, Sebastiaan Y Haffert, Olivier Herscovici-Schiller, Adrien Hours, Roser Juanola-Parramon, Evangelia Kleisioti, Lorenzo Koenig, Maaike van Kooten, Mariya Krasteva, Iva Laginja, Rico Landman, Lucie Leboulleux, David Mouillet, Mamadou N'Diaye, Emiel H Por, Laurent Pueyo, Frans Snik