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Project Progress

We have begun modeling chemosynthetic-based biospheres by coupling together two models: one model codifies a thermodynamic energy balance concept for habitability (Hoehler, 2009); the other model predicts a planet’s atmospheric composition and climate while balancing the redox state of the surface environment (Domagal-Goldman et al., 2014). These models are now coupled together, and we are benchmarking their results against prior work on chemosynthetic-based biospheres on Archean Earth (e.g., Kharecha et al., 2005).

The result of this coupling is the calculation of a self-consistent planetary surface environment, that treats the ecosystem as one system component that is coupled to atmospheric, oceanic, and subsurface system components. We willl be able to predict the standing biomass size, net biological productivity, and resulting gas fluxes to and from a biosphere with a given set of volcanic and hydrothermal inputs to the planetary surface. This will also enable predictions of the secondary effects life has on its environment, including controls on climate and the long-term evolution of the redox state of the planet’s surface and near-surface. Finally, this will aid us in predicting the strength of biosignatures for remote observations and ultimately help us interpret spectra from extrasolar planets.