Vertical Structure Of An Exoplanet’s Atmospheric Jet Stream

Ultra-hot Jupiters, an extreme class of planets not found in our solar system, provide a unique window into atmospheric processes.

The extreme temperature contrasts between their day- and night-sides pose a fundamental climate puzzle: how is energy distributed? To address this, we must observe the 3D structure of these atmospheres, particularly their vertical circulation patterns, which can serve as a testbed for advanced Global Circulation Models (GCM) [e.g. 1].

Here, we show a dramatic shift in atmospheric circulation in an ultra-hot Jupiter: a unilateral flow from the hot star-facing side to the cooler space-facing side of the planet sits below an equatorial super-rotational jet stream.

By resolving the vertical structure of atmospheric dynamics, we move beyond integrated global snapshots of the atmosphere, enabling more accurate identification of flow patterns and allowing for a more nuanced comparison to models. Global circulation models based on first principles struggle to replicate the observed circulation pattern [3], underscoring a critical gap between theoretical understanding of atmospheric flows and observational evidence.

This work serves as a testbed to develop more comprehensive models applicable beyond our Solar System as we prepare for the next generation of giant telescopes.

Julia V. Seidel, Bibiana Prinoth, Lorenzo Pino, Leonardo A. dos Santos, Hritam Chakraborty, Vivien Parmentier, Elyar Sedaghati, Joost P. Wardenier, Casper Farret Jentink, Maria Rosa Zapatero Osorio, Romain Allart, David Ehrenreich, Monika Lendl, Giulia Roccetti, Yuri Damasceno, Vincent Bourrier, Jorge Lillo-Box, H. Jens Hoeijmakers, Enric Pallé, Nuno Santos, Alejandro Suárez Mascareño, Sergio G. Sousa, Hugo M. Tabernero, Francesco A. Pepe

Comments: Accepted for publication in Nature on 16th January 2025, published with DOI https://doi.org/10.1038/s41586-025-08664-1, 5 main figures, 12 main pages plus methods. This work has a companion paper on the same dataset: Prinoth et al. 2025, A&A, DOI: https://doi.org/10.1051/0004-6361/202452405
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2502.12261 [astro-ph.EP] (or arXiv:2502.12261v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2502.12261
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Related DOI:
https://doi.org/10.1038/s41586-025-08664-1
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Submission history
From: J.V. Seidel
[v1] Mon, 17 Feb 2025 19:03:21 UTC (16,115 KB)
https://arxiv.org/abs/2502.12261
Astrobiology,