Modeling Atmospheres with ROCKE-3D: Solar and Extrasolar Worlds
Overview
Understanding the climates of Venus, Earth, and Mars through time is critical to understanding the conditions under which life may begin and flourish. Earth has been habitable for nearly 4 billion years, yet our neighboring worlds Venus and Mars are cautionary tales, where no signs of present or previous life have been found thus far. Our planetary research group at the NASA Goddard Institute for Space Studies (GISS) develops and utilizes a 3D General Circulation Model (GCM) known as ROCKE-3D to model the atmospheres and/or oceans of terrestrial worlds. These simulations assist NASA in targeting neighboring and extrasolar worlds with specific missions (e.g., Mars Curiosity rover, James Webb Space Telescope) and can act as benchmarks to constrain our understanding of newly discovered exoplanets in the habitable zone.
Project Details
Recent ROCKE-3D climate simulations include a) an exoplanetary world around Proxima Centauri, b) a temperate ancient Venus, c) a deep future-time Earth with two different supercontinent configurations, and d) an ancient hypothetical ancient lunar atmosphere.
We use the best available data to set up our climate simulations. For Proxima Centauri b (a super Earth exoplanet that orbits an M-type star) we know nothing more than its orbital characteristics, estimates of mass/density, and how much sunlight it receives, so we model a simple water-covered “aquaplanet.” For ancient Venus we use present-day topography and supply it with five different water reservoirs that fit within the error bars of past water estimates. For future Earth, we use sophisticated geodynamics models to construct two alternative supercontinent outcomes 200–250 million years into the future alongside the expected increase in solar luminosity. For the Moon, we use estimates of volcanic water outgassing to model where such water would be deposited long-term—at the poles in regions devoid of sunlight.
Results and Impact
Proxima Centauri b: Using the first fully coupled atmosphere+ocean model of this world, we discovered that the transport of heat by the ocean is a key factor in its likely habitability. Compared to a simulation with a shallow simple ocean, our simulation with a fully coupled dynamic ocean produced a global mean surface temperature 16°C warmer!
Ancient Venus: We were the first to use a forward modeling approach to piece together an entire climate history for Venus that fits within observational constraints. We demonstrated that Venus could have had temperate conditions for much of its history and may have been the first habitable world of this solar system.
Earth’s Future Supercontinents: The Aurica low-latitude supercontinent has a global mean surface temperature 7°C warmer than today. This is expected given its lack of high-latitude continents like on present-day Earth and its relative 2.5% increase in solar luminosity. The Amasia supercontinent (with the main continents pushed north of the equator while Antarctica remains in place) is 3–7°C warmer. The +3°C result is surprising but shows that the mean altitudes of mountain ranges play a key role in ice sheet coverage driving the temperature lower.
Ancient Lunar Atmosphere: Ours was the first time a 3D GCM was applied to study the effects of volcanic outgassing at lower latitudes from the maria plains and transport of water to the permanently shadowed regions of the poles. We will soon be able to put constraints on the amount of water delivered, which may be measured by Artemis program astronauts in the near future.
Why HPC Matters
The NASA Center for Climate Simulation (NCCS) is vital to the success of our projects. The constancy of processor type and increasing speed and storage enable our relatively small development group to put resources into science development and less into reconfiguring code for the “latest and greatest” computing architecture. The four projects detailed used on the order of 7 million core-hours on the NCCS Discover supercomputer. Compiler support by the highly capable NCCS staff is also important to our success. In addition, we rely on the NCCS DataPortal to distribute our results simply and quickly to the community.
What's Next
The ROCKE-3D modeling group will continue to apply their expertise to constraining the habitability of new exoplanetary worlds being discovered by NASA’s Transiting Exoplanet Survey Satellite and Webb missions, more accurately modeling the long-term climate history of Venus guided by results from new missions sent by NASA (DAVINCI and VERITAS) and the European Space Agency (EnVision), and helping to discern the origin of water in the Moon’s permanently shadowed polar regions in conjunction with expected revolutionary discoveries from NASA’s Artemis program.
Presentation
More Information
- How Long Was Venus Habitable?
- Earth Will Become One Big Supercontinent Again, And It Will Probably Kill Us, Scientists Say
- NCCS DataPortal Containing ROCKE-3D Results and Simulation Setup Data
- Guide to Using ROCKE-3D and YouTube Tutorials
Researchers
- Michael Way, NASA Goddard Institute for Space Studies Please enable Javascript to see email address.
