Effects of obliquity and water vapor/trace gas greenhouses in the early martian climate

摘要: [1] We explore possible mechanisms for the generation of warm, wet climates on early Mars as a result greenhouse warming by both water vapor and periodic volcanic trace emissions. The presence (a strong gas) other gases (such SO2) in predominantly CO2 atmosphere may act, under certain conditions, to elevate surface temperatures above freezing point liquid water, at least episodically. Variations obliquity are explored investigate whether these variations insolation can broaden regions or seasons where warm exist. We use Weather Research Forecasting general circulation model perform several simulations conditions martian containing find global be cooler than elevated levels suggested one recent study Johnson et al. (2008). While achieving 273 K globally remains challenging, additional states permit widespread seasonally which help explain fluvial features (e.g., valley networks) hydrous minerals post-Noachian age, period when alternate methods do not convincingly sustainability water. Furthermore, we that achieved with darker globally, is consistent exposure unweathered basaltic bedrock large ocean sea.