Simulations of Planetary Climates with ROCKE-3D

The ROCKE-3D general circulation model (GCM), an outgrowth of the parent GISS Earth GCM ModelE, is designed to study different points in the history of our own planet and other Solar System terrestrial planets, as well as exoplanets. Our research supports NASA's objective to search for life elsewhere by determining which types of planets are most likely to be habitable and what NASA might do to characterize these planets and eventually find evidence of life. On this page we provide results obtained from simulations of several planets and various time periods.

The user can select parameters on the form below to create maps of a variety of climate variables for a planet chosen in Data Source A. If two different time periods or planet configurations for a given planet are chosen as Data Sources A and B, the resulting figure will be the difference between A and B. Brief descriptions of each planet or time period are given below. Please take note of comments regarding the continent outlines for the Huronian and Archaean Earth simulations.

Note that generating figures takes 5 or 6 seconds; please be patient.

Simulated Planets

Proxima Centauri b

A planet discovered orbiting the star nearest to Earth. It is not known whether Proxima Centauri b has an atmosphere or how fast it rotates. We show three hypothetical climates:

  1. A planet that keeps the same face toward the star at all times, with an Earthlike 1 bar atmosphere made of N2 and 376 ppmv of CO2
  2. A planet that keeps the same face toward the star at all times, with a 1 bar CO2 atmosphere
  3. A planet that rotates on its axis 3 times for every 2 orbits around its star, with an Earthlike atmosphere made of N2 and 376 ppmv of CO2

Further discussion of these simulations appears in Del Genio et al. (2018).

Ancient Earth

Four periods going successively farther back in time:

  1. The Cretaceous Period of the Phanerozoic Eon (circa 100 million years ago), a “greenhouse” interval when dinosaurs roamed the Earth, the continents were more closely spaced, and the climate was warmer than today due to an increased level of CO2. We simulate the Cretaceous here with a CO2 level of 1140 ppmv (~1.15 mb), 4 times greater than the modern pre-industrial value.
  2. The Sturtian glacial interval of the Proterozoic Eon (circa 715 million years ago), when the climate was very cold thanks to multiple factors that include a Sun that was 6% dimmer than today, and reduced greenhouse gas warming (here simulated by a CO2 level of just 40 ppmv, or ~0.04 mb). The supercontinent Rodinia was just beginning to break apart, with most land masses still closely packed near the equator.
  3. The Huronian glacial interval of the Proterozoic Eon (circa 2.1 billion years ago), when the climate was so cold that the Earth’s oceans could have frozen over entirely, making Earth look like a snowball. Factors that led to this ice age include a Sun that was 16% dimmer than today, and reduced greenhouse gas warming (here simulated by a CO2 level of 40 ppmv, ~0.04 mb) that may have been caused by the first significant increase in atmospheric oxygen. We are unsure where the continents were at this time, so this simulation uses the same configuration as the Sturtian.
  4. The Mesoarchean Era of the Archean Eon (circa 2.9 billion years ago), when the Sun was 20% dimmer than today, oxygen was not yet present, and it was likely that the atmosphere had much more CO2 (10 mb) and CH4 (2 mb) than it does today. Earth’s land-ocean configuration is at this time is unknown (the continents may not even have been exposed); the simulation assumes modern Earth continents. (Further discussion of this time appears in De Genio et al. (2020).)

Ancient Venus

Today Venus has a thick, hot CO2 atmosphere and is uninhabitable. But early in its history, it may have been more like Earth. This simulation shows a hypothetical ancient Venus 2.9 billion years ago under a 20% dimmer Sun, assuming that Venus rotated as slowly as it does now (once every 243 days), had a modern Earthlike atmosphere (1 bar N2 and 400 ppmv of CO2), and had a shallow 310 m ocean that filled in its current lowland areas. The simulation portrays a two-month period of Venus's year to emphasize the solar heating of the dayside.

Further discussion of these simulations appears in Way et al. (2016).

Modern Earth

The time period covered goes from the pre-industrial (1850) era to current times. Selected experiments for the CMIP6 project are shown, including investigations of some future scenarios and sensitivity tests for various forcings.

References and Use

Please see the GISS Astrobiology — NExSS ROCKE-3D project for more information related to this research.

These results are freely available for public use. We request that if you use them in any publication or online application, you acknowledge the NExSS ROCKE-3D project and cite:

Way, M.J., I. Aleinov, D.S. Amundsen, M.A. Chandler, T. Clune, A.D. Del Genio, Y. Fujii, M. Kelley, N.Y. Kiang, L. Sohl, and K. Tsigaridis, 2017: Resolving Orbital and Climate Keys of Earth and Extraterrestrial Environments with Dynamics 1.0: A general circulation model for simulating the climates of rocky planets. Astrophys. J. Supp. Series, 231, no. 1, 12, doi:10.3847/1538-4365/aa7a06.

Related papers include:

Way, M.J., A.D. Del Genio, N.Y. Kiang, L.E. Sohl, D.H. Grinspoon, I. Aleinov, M. Kelley, and T. Clune, 2016: Was Venus the first habitable world of our solar system? Geophys. Res. Lett., 43, no. 16, 8376-8383, doi:10.1002/2016GL069790.

Del Genio, A.D., M.J. Way, D.S. Amundsen, I. Aleinov, M. Kelley, N.Y. Kiang, and T.L. Clune, 2018: Habitable climate scenarios for Proxima Centauri b with a dynamic ocean. Astrobiology, 19, no. 1, 99-125, doi:10.1089/ast.2017.1760.

Del Genio, A.D., D. Brain, L. Noack, and L. Schaefer, 2020: The inner Solar System's habitability through time, in Planetary Astrobiology, University of Arizona Press, in press

Contact

Please address scientific inquiries about these data to Dr. Michael Way.

➤ Go to GISS Astrobiology / NExSS Project