Angular momentum and heat transport on tidally locked hot Jupiter planets

Abstract

The atmospheric circulation in the upper atmosphere of hot Jupiter planets is strongly influenced by the incoming stellar radiation. In this work we explore the results from a 3D atmospheric model and revisit the main processes driving the circulation in hot Jupiter planets. We use the angular momentum transport as a diagnostic and carry out a Fourier analysis to identify the atmospheric waves involved. We find that the coupling between the angular momentum transported horizontally by the semi-diurnal tide and the mean circulation is the mechanism responsible for producing the strong jet at low latitudes.Our simulations indicate the possible formation of atmospheric indirect cells at low latitudes. The formation of these cells is induced by the presence of the semidiurnal tide that is driven by the stellar irradiation. The tropical circulation has an important impact transporting heat and momentum from the upper towards the lower atmosphere. One of the consequences of this heat and momentum transport is a global increase of the temperature.We show that the initial conditions do not affect the output of the reference simulation. However, when the period of rotation of the planet was increased (P rot > 5 Earth days), vertical transport by stationary waves became stronger, transient waves became non-negligible, and Coriolis influence less dominant, which allowed a steady state with a strong retrograde jet to be stable. We found that at least two statically steady state solutions exist for the same planet parameters.

The rotational and divergent components of atmospheric circulation on tidally locked planets

“…The fact that the majority of day-night heat transport is due to the divergent circulation, for both the terrestrial planet and the hot Jupiter, is an important result, as some previous work studying day-night heat transport on tidally locked planets has focused entirely on the role of the jet and stationary waves (43,51,52). The red line in Fig.…”

Grid of pseudo-2D chemistry models for tidally locked exoplanets – I. The role of vertical and horizontal mixing

“…The assumed temperature profile in the deep part of the atmosphere is crucial to the chemistry, not only locally, but throughout the vertical extent of the atmosphere if quenched. However, unlike the 3D temperature structure at lower pressures, which can be relatively well constrained with a GCM, the deep thermal structure is often ill-constrained by GCMs, because it evolves very slowly (Carone et al 2020;Mendonça 2020;Wang & Wordsworth 2020;Showman et al 2020). This can result in temperature-profiles that are only partially converged, featuring a small thermal inversion in the deep ( ≈ 10 bar) layers (e.g.…”

“…Especially the deep atmospheric layers ( > 10 bar), which have a comparatively long radiative timescale, have been noted to evolve very slowly (e.g. Amundsen et al 2016), leading to impractically long computation time requirements (Wang & Wordsworth 2020;Mendonça 2020). Moreover, it has been shown that, in some cases, the deep atmospheric evolution can have a dynamical feedback on the observable atmospheric layers above (Carone et al 2020).…”

Simulating gas giant exoplanet atmospheres with Exo-FMS: Comparing semi-grey, picket fence and correlated-k radiative-transfer schemes

“…The agreement in jet structure is notable in view of the very different dynamical cores used in the two simulations and demonstrates that the use of the cube sphere grid has not distorted the relevant angular momentum transport processes, since the jet speed is sensitive to angular momentum transport (Mendonça 2020).…”