| The role of ocean biogeochemistry in Earth's carbon, oxygen, and nutrient cycles:
Earth's oceans dynamically integrate global metabolic function, regulate atmospheric chemistry, and stabilize the climate system. Together with colleagues at the University of California, Riverside and Yale University we seek to forge a better mechanistic understanding of the major factors controlling ocean biogeochemistry on Earth across a range of timescales, and how they have evolved throughout Earth's history. This work involves the development and application of new computational modeling tools, interrogation of Earth's geochemical record, and calibration of geochemical proxies and theoretical models using modern analog systems. More info can be found here and here.
Right: 3-D ocean biogeochemistry model of the methane cycle, showing column-integrated (top) and zonally averaged (bottom) rates of methanogenesis and aerobic methanotrophy. |
| Using the Earth system to sequester carbon from the atmosphere:
Above: Seasonality in precipitation rates across agricultural regions of the coterminous United States, potential sites of enhanced silicate rock weathering.
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Avoiding many of the most severe consequences of anthropogenic climate change in the coming century will very likely require the development of "negative emissions technologies" - practices that lead to net removal of carbon dioxide from Earth's atmosphere. Ideally, these technologies would be scalable, economical, and minimally invasive. Together with colleagues at Texas A&M and Yale University, we have recently begun to explore approaches toward the directed enhancement of natural Earth system processes that act to remove carbon from Earth's atmosphere. In particular, we are interested in exploring the potential of enhanced silicate rock weathering - in both terrestrial and marine systems - as a means toward both sequestering carbon across a range of timescales and potentially yielding a number of parallel ecosystem benefits.
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| Atmospheric biosignatures on habitable worlds:
Thousands of planets beyond our solar system have been discovered to date, dozens of which are rocky in composition and are orbiting within the habitable zone of their host star. The next frontier in life detection beyond our solar system will be detailed characterization of the atmospheres of potentially habitable worlds. Leveraging these observations effectively will require a comprehensive understanding of the factors controlling the emergence and maintenance of atmospheric biosignatures - signatures of surface life in atmospheric chemistry that can be detected across interstellar distances. Together with colleagues at the University of California, Riverside, Purdue University, Yale University, and NASA Goddard Space Flight Center we work to develop modeling tools and interpretive frameworks that we hope will contribute to a more robust search for life beyond our solar system. Central to this pursuit is the contention that understanding Earth system evolution can provide substantive insight into observational and interpretive frameworks in exoplanet system science.