JWST has provided a new wealth of information on exoplanet atmospheres, including one of the most critical components, that being the composition of cloud particles and their 3D global distribution.

In this review talk, I will first outline the basic theories and multiple approaches applied cloud formation in exosolar atmospheres, as well as their general effects on the observed properties of exoplanet atmospheres. Moving through the historical context in brown dwarf atmosphere science to contemporary modelling efforts will serve to provide the audience with a broad literature review and context to the field. A simple interactive python based demonstration will be included to aid understanding of the basic methodology.

Moving into 3D, I will discuss how the field approaches this tricky topic using general circulation models (GCMs) coupled to various flavours of cloud models, from simple diagnostic efforts to complex microphysical models. I will showcase recent progress in the field using these techniques and how they have been used to uncover the complex interactions and feedbacks that clouds can induce in these atmospheres. Another interactive session will elucidate the time-dependent nature of cloud formation in 3D and the modelling of microphysics.

Lastly, I will suggest what types of observational data and programs would best constrain the 3D properties of clouds in exoplanet atmospheres, as well as discuss gaps in theory and data that can be can tackled in future endeavours in the field.

Elspeth Lee is currently a postdoctorate Bernoulli Fellow at the Center of Space and Habitability (CSH), University of Bern, Switzerland. Her primary research investigates complex feedback interactions between clouds, chemistry, radiative-transfer and dynamics using 3D atmospheric models. She has developed several 3D capable models such as gCMCRT (Monte Carlo radiative-transfer), mini-chem (kinetic chemistry) and mini-cloud (cloud formation microphysics).

The great distance to exoplanets makes it impossible to resolve their disk with current or near-term technology. It is still possible, however, to deduce spatial inhomogeneities in exoplanets provided that different regions are visible at different times—this can be due to rotation, orbital motion, or occultations by a star, planet, or moon. We can also monitor atmospheric time-variability due to seasons and weather. Finally, winds can be directly probed via Doppler-shifted atmospheric lines. I will review techniques for mapping the atmospheric dynamics of exoplanets at low and high spectral resolution for synchronously rotating planets, eccentric planets, those on long-period orbits, and free-floating planets. I will outline how we constrain the wind direction, wind speed, vertical mixing, atmospheric variability, cloud and chemical inhomogeneities.

Nicolas Cowan is the Canada Research Chair in Planetary Climate and an Associate Professor in the departments of Physics and of Earth & Planetary Sciences at McGill University. He is a member of the Trottier Space Institute and l’Institut de recherche sur les exoplanètes. Cowan uses telescopes and maths to study the climates of exoplanets. He has pioneered remote sensing techniques to map the atmospheres and surfaces of these distant planets, bringing them into view as multi-dimensional worlds unto themselves.

The discovery of more than 6,000 exoplanets imposes outstanding questions related to our origins: How do planets evolve? Is our Solar System common? How and where can life emerge? To answer these fundamental questions, we need to understand the physical processes underlying the formation and evolution of planets, principal among them atmospheric escape. Since 2003, we have used space- and ground-based observatories to detect evaporating exoplanets in transit spectroscopy, as well as the end-products of photoevaporation (i.e., bare-rock planets orbiting M dwarfs), but it seems that the more we observe, the more mysteries emerge. Great sophistication is now required of physical models to help us understand some of these mysteries, and we cannot ignore anymore complications such as three-dimensionality, stellar activity, magnetic field interactions, and the impact of metallicity. In this talk, I will discuss some of the major discoveries in this research area, as well as avenues for further advancing our understanding of atmospheric evolution beyond the Solar System.

Leonardo dos Santos is an Assistant Astronomer at the Space Telescope Science Institute, having previously obtained his PhD from the University of Geneva and Master's from the University of São Paulo. Leonardo is one of the leads of the Transiting Exoplanets research group at STScI and specializes in observational and theoretical studies of atmospheric escape in planetary systems. He is also an instrument scientist for the Cosmic Origins Spectrograph aboard the Hubble Space Telescope, the most sensitive UV instrument currently in operation.

The atmospheric chemistry of gas giants - both within our Solar System and beyond - offers critical insights into their formation and evolution, as well as their atmospheric dynamics. In this talk, I will review recent advances in our understanding of the chemical processes that shape the atmospheres of Jupiter, Saturn, Uranus, and Neptune, and those of extrasolar hot Jupiters. I will explore progress made on major outstanding questions, such as the unexpected depletion of ammonia in Jupiter's troposphere. In parallel, I will examine the current state of chemical kinetics networks used to model these atmospheres and highlight gaps in available kinetics data. I will conclude by discussing the connections between gas giants in our Solar System and their extrasolar counterparts.

Maria Zamyatina is a postdoctoral research fellow at the University of Exeter. Trained as an Earth scientist, she transitioned to astronomy in 2020 after obtaining her PhD. She studies climates of planetary atmospheres using a 3D chemistry-climate model, and focuses on the interactions between the gas-phase chemistry and atmospheric dynamics.

In the past three years, JWST has brought the atmospheres of super-Earths and sub-Neptunes into view, raising new questions about their interior compositions and origins. However, the atmospheric compositions we measure are not necessarily representative of the bulk planet. Interpreting JWST measurements in the context of planetary interiors and formation therefore requires consideration of the atmosphere-interior connection. Different temperature regimes can provide complementary information, from the evaporating surfaces of lava worlds to the larger atmospheric scale heights of mini-Neptunes. In this talk, I will discuss recent JWST observations, and some of the key atmosphere-interior interactions needed to connect them to the planetary interior.

Anjali Piette is an Assistant Professor at the University of Birmingham, where her work focusses on characterising the diversity of exoplanetary environments through their atmospheres. Originally from the UK, Anjali completed her PhD at the University of Cambridge. She then took up a Carnegie Postdoctoral Fellowship at the Carnegie Earth and Planets Laboratory in Washington, DC, before moving to Birmingham.

The atmospheric dynamics of the Solar System's gas giants-Jupiter, Saturn, Uranus, and Neptune-serve as a natural laboratory for understanding rapidly rotating giant atmospheres. Despite their diverse characteristics, they exhibit intriguing similarities such as large-scale alternating zonal jet streams, prominent vortices, and wave activity, suggesting potential common dynamical mechanisms driven by rotation, convection, and differential heating. Leveraging advanced observational data and state-of-the-art numerical modeling, we are increasingly able to disentangle these processes. One of the most interesting puzzles is the contrasting behavior of equatorial jets- prograde on gas giants versus retrograde on ice giants-which often leads to differentiated treatment between these planetary types. We will examine this and offer an alternative perspective. Understanding the atmospheric dynamics of these solar system giants provides an important context for interpreting the growing wealth of data from exoplanets with similar bulk properties, anticipated to expand with missions like PLATO and Ariel. This review synthesizes the principles governing these atmospheres, highlights open questions, and discusses their broader relevance for planetary science.

Keren is a postdoctoral fellow at Leiden Observatory and SRON, where she focuses on the deep dynamics of gas giants, including zonal jets, circulation, gravity, and stable layers, in collaboration with Dr. Yamila Miguel. Her research involves studying (exo)planetary atmospheres through theoretical models, GCMs, and observational data. She earned her Ph.D. and MSc under Prof. Yohai Kaspi at the Weizmann Institute of Science and holds a Bachelor's degree in Earth Sciences from the Hebrew University of Jerusalem.

In recent years, high resolution spectroscopy (HRS; R ⪆ 20,000) from ground-based telescopes in the optical and near-infrared has proven to be a powerful probe of exoplanet atmospheres. Through transmission spectroscopic observations during transits, and phase-curve observations of both transiting and non-transiting exoplanets throughout their orbits, we have been able to investigate the chemical compositions, atmospheric dynamics, and temperature structures of a diverse range of exoplanetary systems. In this review talk, I will first introduce the methods used to study exoplanet atmospheres via HRS, and provide an overview of the current suite of spectrographs and telescopes being employed for this work. I will demonstrate how HRS allows us to disentangle exoplanet signals from both stellar and telluric contamination, and show how these methods can be used to probe atmospheric chemistry through single-line detections as well as cross-correlation techniques that leverage hundreds to thousands of spectral lines simultaneously. Following this, I will provide a broad overview of atmospheric species detected to date, and outline how these detections can be used to gain insights into exoplanet formation and evolution. I will then discuss recent advances in the field, such as synergies with lower-resolution, space-based observations, as well as work making use of time-resolved detections to shed light on the inherently 3D nature of exoplanet atmospheres. Finally, I will look ahead to open questions that may be answered by the next generation of high-resolution spectrographs, including those on extremely large telescopes. I will conclude by highlighting current work and ongoing surveys harnessing HRS to expand our understanding of atmospheric chemistry across a diverse range of exoplanets.

Emily Deibert (she/her) is a Gemini Science Fellow at the Gemini South Observatory in La Serena, Chile, where her research focuses on characterizing the atmospheres of ultra-hot Jupiters with the new Gemini High-resolution Optical SpecTrograph (GHOST). Prior to beginning at Gemini, Emily completed a PhD in Astronomy & Astrophysics at the University of Toronto, where she worked on high-resolution spectroscopy of exoplanet atmospheres in the optical and near-infrared. In early 2026, she will begin a Banting Postdoctoral Fellowship at the University of Waterloo.