Presentation #102.160 in the session Poster Session.
The atmospheres of sub-Neptunes are expected to exhibit considerable chemical diversity, beyond what is anticipated for gas-giant exoplanets. In my talk, we explore self-consistent atmosphere-interior models of sub-Neptunes to explore this chemical diversity and apply this knowledge to the available atmospheric data of GJ 436b. In particular, we constrain the properties of the interior and atmosphere of the planet based on the available Spitzer measurements. While it is possible to fit the emission spectrum of GJ 436 b using a high-metallicity model, we demonstrate that such an atmosphere is inconsistent with physically plausible interior structures. It remains the case that no existing study can adequately fit the 4.5 microns Spitzer secondary eclipse measurement, which is probably caused by chemical disequilibrium.