Modeling Effects of Stellar UV-Driven Photochemistry on the Transit Spectra of Moist Rocky Atmospheres Around M Dwarfs

摘要

3-D climate modeling has shown that tidally-locked terrestrial planets, at the inner habitable zone edge (IHZ) of M dwarf stars with T_(eff) > 3000 K, are able to retain a "moist" atmosphere (i.e. a water vapor rich stratosphere). However, flaring M dwarfs have strong UV activity, which may photodissociate this H_2O. Here, we employ a 1-D photochemical model with varied stellar UV, to assess whether H_2O loss driven by high stellar UV would affect H_2O detectability in JWST transmission spectroscopy. Temperature and water vapor profiles are taken from published 3-D climate model simulations of an IHZ Earth-sized planet around a 3300 K M dwarf with an N_2-H_2O atmosphere; they serve as self-consistent inputs for the 1-D model. We explore additional chemical complexity within the 1-D model by introducing other atmospheric species. In this paper, we review our methodology, focusing on the 1-D photochemical model.