This session brings together new indevelopments in the characterisation of exoplanet climate regimes based on observations with, for example, JWST and CHEOPS and also new advances in theoretical modelling triggered by new observations. E.g. JWST for the first time observed features of solid particles which have been interpreted as signatures of mineral clouds in transition spectra of gas giant exoplanets. Smaller space telescopes like TESS and CHEOPS provide equally important insight into the physics of exoplanet atmospheres. TESS, CHEOPS and JWST phase curves and secondary eclipse spectra point to the need of a magnetically coupled atmospheric gas because the observable dayside of ultra-hot Jupiters is dominated by charged particles. While all these processes have been predicted for exoplanets before they could be observed, planetary clouds and magnetic fields have been studied for solar system planets in situ with many space missions.

This session aims to present recent progress in exoplanet atmosphere characterisation based on a combination of observation and modelling. The session focuses on cloud and gas-phase chemistry modelling, the modelling of magnetic coupling and charged particles in atmospheres and how these have and can be observed. Contributions working on the cross-over of solar system and exoplanet sciences are particularly welcomed.

This session is triggered by the upcoming PLATO launch at the end of 2026 and ongoing CHEOPS-PLATO synergies, including atmospheric characterization of hot to ultra-hot Jupiters facilitated by optical observations (secondary eclipse measurements/phasecurves) that are highly complementary to JWST observations in the infrared. The session will also discuss atmosphere interpretation activities on incorporating complex 3D modelling in their data interpretation. This session is further part of the PLATO WP activities for exoplanet gas giants.