Periodic Reporting for period 2 - EXOKLEIN (The Climates and Habitability of Small Exoplanets Around Red Stars)
Reporting period: 2019-08-01 to 2021-01-31
Research Theme 2 aims to generalise Earth-centric understanding of geochemical cycles and is led by Dr. Kaustubh Hakim (Ph.D University of Amsterdam), who has training in astrophysics and experimental geology. Dr. Hakim spent the first year of the project studying the effects of varying lithology (rock composition) on the weathering process of the carbon cycle and the manuscript (30+ pages) has been accepted for publication in the Planetary Science Journal.
Research Theme 3 aims to understand the long-term stability of biosignature gases and is led by Dr. Pierre Auclair-Desrotour (Ph.D Paris Observatory), who has training in astrophysics. Dr. Auclair-Desrotour spent the first year of the project establishing a theoretical framework to study atmospheric collapse, which is the phenomenon that greenhouse gases may suffer runaway condensation on the permanent nightside of a tidally locked exoplanet. The framework allows for the wide exploration of atmospheric conditions (i.e. parameter scanning) and identifies interesting case studies for GCMs to focus on. Our findings are reported in Auclair-Desrotour & Heng (2020, Astronomy & Astrophysics, 638, A77).
An unanticipated development of the project is the discovery of a novel mathematical solution to the radiative transfer equation and novel mathematical formulae for the albedo and phase curves of exoplanets, which has major implications for the analysis and interpretation of data measured by present and future state-of-the-art space- and ground-based telescopes. These formulae are the first new ones to be discovered since the seminal work of Hapke (1981) and Lambert (18th century).