The global warmth of the Miocene Climatic Optimum (MCO, ~15 Ma) offers valuable insights into warm climate dynamics and future climate change, providing a real-world testbed for validating climate models. However, it remains unclear how warm the MCO was given the scarcity and uncertainties of surface temperature proxy records. Three iCESM1.3 long simulations are constructed to estimate the Miocene global mean surface temperature (GMST). The three simulations included: preindustrial (PI), 1.5x CO2, 3x CO2. Each simulation case includes long time series files with a monthly temporal resolution and a NE16 G16 spatial resolution (~2 degree atmosphere and ~1 degree ocean), covering the last 100 model years of the global climate fields.

Further details are provided in the paper below:

  • Zhu, F, Zhu, J., Si, W., Nirenberg, J.E., Herbert, T., Tierney, J.E., Acosta, R.P., Burls, N.J., Evans, D., 2026. Modeldata synthesis of benthic isotopes suggests a warmer Miocene Climatic Optimum. Nature Communications. In Revision. Preprint

We kindly ask that you reference the appropriate paper(s) and acknowledge the PaleoclimateWG and computing resources from NSF and NCAR CISL when presenting results based on these simulations in either oral or written form. 

Project Details

  • Simulation Names:
    • MCO 3xCO2: b.e13.B1850C5.ne16_g16.icesm131_d18O_fixer.Miocene.3xCO2.005
    • MCO 1.5xCO2: b.e13.B1850C5.ne16_g16.icesm131_d18O_fixer.Miocene.1.5xCO2.005
    • PI: b.e13.B1850C5.ne16_g16.icesm131_d18O_fixer.PI.tuning.110
  • Model Versions: iCESM1.3 (with water isotopes and CAM5 physics)
  • Resolution: ne16np4_gx1v6 (nominal 2° atmosphere/land and 1° ocean/sea ice)
  • Years:  9000 years for MCO 3xCO2, 5000 years for MCO 1.5xCO2, and 5000 years for PI
  • Ensemble Size: one
  • Time Frequencies Saved: Monthly
  • Machine: Derecho
  • Compsets: B1850C5

Data Acquisition

The simulation data are publicly available from the NSF NCAR GDEX: 

https://gdex.ucar.edu/datasets/d010026/

They are also accessible on the NWSC campaign storage path: 

/glade/campaign/collections/gdex/data/d010026

or via the Globus Guest Collection:

https://app.globus.org/file-manager?origin_id=c4e40965-a024-43d7-bef4-6010f3731b61&origin_path=%2Fd010026%2F

Diagnostics

Diagnostics for the Miocene simulations may be added later.