Presentation #111.09 in the session “Extrasolar Planets: Atmospheric Models”.
Atmospheric models of exoplanets used to explain observed data typically assume a one-dimensional thermally averaged structure. However, General Circulation Models (GCMs) reveal much more complex temperature profiles that can vary with longitude and latitude across the terminator region of the atmosphere. When observing a planet’s atmosphere in transmission, we are probing a region whose temperature profile may change significantly in the transition from day- to night-side across the terminator. The magnitude of the change depends on various atmospheric parameters, such as the planet’s irradiation, rotation and composition, and is often not considered when creating model transmission spectra to interpret data. In this talk we explore how model spectra can change when multi-dimensional effects are incorporated in the temperature structure. We use results from established GCMs to identify the key ways and conditions in which 3D temperature profiles in the terminator region may differ from their 1D averaged counterparts. We then incorporate these effects into a transmission spectrum model in order to investigate differences between model spectra produced with a 3D structure and those created under the assumption of a 1D temperature profile. We also explore the extent to which current and future telescope data can provide meaningful information about these effects, as well as considering how other inferences that may be made from this data, such as the abundances of various molecular species, might change when the assumption of a 1D temperature profile is removed. We discuss possible future applications of our work as well as the challenges associated with taking a 3D approach to the interpretation of data from exoplanet atmospheres.