EEPS Seminar: Chris Reinhard, Georgia Tech
Abstract Title: Nutrients, ecosystems, and the chemical evolution of Earth’s atmosphere
Abstract – Pending
The chemistry of Earth’s atmosphere has changed dramatically over time, and this evolution has been inextricably linked with innovations in biological metabolism and ecosystem complexity. A prominent example is the evolution of Earth’s oxygen cycle – the accumulation of significant quantities of oxygen in the ocean-atmosphere system has completely reshaped electron flow through Earth’s surface environments, and provides a conspicuous remotely detectable signal of a pervasive biosphere. The oxygen cycle is in turn governed by feedbacks linking it with the carbon and sulfur cycles, the cycling of major and trace nutrients, and the exchange of volatiles with Earth’s interior. This talk will explore the apparently protracted oxygenation of Earth’s ocean-atmosphere system in the context of an evolving photosynthetic biosphere, with an eye toward the roles of nutrient cycling and ecosystem structure in regulating atmospheric chemistry. The implications of these results will then be discussed in the broader context of climate stability and the emergence and maintenance of atmospheric biosignatures on Earth-like planets.