12 February 2025: Martha Mak

Speaker: Martha Mak (Exeter)

Date: Wednesday 12 February 2025

Time: 15:00

Location: 3.21

Simulating Hazy Exoplanets from Earth-like to Hot-Jupiter: Role of Haze in Habitability and Observabilities?

Hazes, solid-state photochemical product, are expected to be present from the early Earth to exoplanets. However, our limited knowledge of haze and the lack of studies are presenting a significant barrier in our understanding of its impact on the atmospheric dynamics, as well as interpreting observations. In this talk, I will present results from 3D simulations of photochemical haze in the atmosphere of the Early Earth and WASP-39b using the 3D general circulation model - the Met Office Unified Model. For the Early Earth, we found global warming and cooling when the haze layer is thin and thick, respectively. We suggest that a thin haze layer might be able to provide a temperate environment conducive to life both on Earth and beyond. For WASP-39b, we find that haze can drastically alter the thermal structure and atmospheric circulation, but the haze distribution is largely determined by the superrotating jet and the eddies under all circumstances. Our results also suggest that the radiative impact of haze can result a larger transit depth over the morning terminator than the evening terminator, providing a new indicator in determining the presence of haze in the atmosphere through such observational limb asymmetry.