Effect of Mars Atmospheric Loss on Snow Melt Potential in a 3.5 Gyr Mars Climate Evolution Model

摘要: Post-Noachian Martian paleochannels indicate the existence of liquid water on surface Mars after about 3.5 Gya [Irwin et al., 2015; Palucis 2016]. In order to explore effects variations in CO2 partial pressure and obliquity possibility water, we created a zero-dimensional energy balance model. We combine this model with physically consistent orbital histories track conditions over last 3.5 Gyr history. find that melting is allowed for atmospheric pressures corresponding exponential loss rates dP/dt∝t−3.73 or faster, but rate within 0.5σ calculated from initial measurements made by Atmosphere Volatile EvolutioN (MAVEN) mission, if assume all escaping oxygen measured MAVEN comes CO2[Lillis 2017; Tu 2015]. Melting at matches selected key geologic constraints formation Hesperian river networks, assuming optimal melt during warmest part each year Stopar 2006; Kite 2017a,b].. The has larger effect than changes Mars's mean obliquity. These results show atmosphere are being dominant process switched melt-permitting melt-absent climate [Jakosky 2017], non-CO2 warming will be required <2 Gya confirmed, most H2O.