A Suite of Perturbed Parameter Ensembles under a Wide Range of Temperatures

We performed a suite of CAM6 perturbed parameter ensembles (PPEs) to explore climate and hydroclimate dynamics under a wide range of sea surface temperature (SST) conditions. The SST varies from 4K colder to 16K warmer than preindustrial levels, encompassing a broad spectrum of mean temperatures spanning the past 65 million years. The PPEs offers valuable insights into climate and hydroclimate responses, as well as weather and climate extremes under diverse conditions.

The PPEs consist of nine suites of simulations with different SST scenarios: preindustrial (PREI), 4K cooler (M04K), and 4K, 8K, 12K, and 16K warmer (P04K to P16K). For SSTs exceeding 8K warming, sea ice was removed to improve numerical stability. Each PPE set consists of 250 ensemble members, with 45 parameters related to microphysics, convection, turbulence, and aerosols perturbed using Latin Hypercube Sampling. An additional simulation with default parameter settings brings the total to 251 simulations, each running for five years using CAM6.3.

cloud feedback in paleoPPE

Global mean and zonal mean cloud feedback for different background states with uniform 4-K warming in SST.

Further details and background information can be found in the papers below:

  • Zhu et al., in revision. Investigating the State Dependence of Cloud Feedback Using a Suite of Perturbed Parameter Ensembles, Journal of Climate

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:
    • PREI: f.c6.F1850.f19_f19.paleo_ppe.sst_prei.ens251
    • M04K: f.c6.F1850.f19_f19.paleo_ppe.sst_m04k.ens251
    • P04K: f.c6.F1850.f19_f19.paleo_ppe.sst_p04k.ens251
    • P08K: f.c6.F1850.f19_f19.paleo_ppe.sst_p08k.ens251
    • P08K without sea ice: f.c6.F1850.f19_f19.paleo_ppe.sst_p08k_noIce2.ens251
    • P12K without sea ice: f.c6.F1850.f19_f19.paleo_ppe.sst_p12k_noIce2.ens251
    • P16K without sea ice: f.c6.F1850.f19_f19.paleo_ppe.sst_p16k_noIce2.ens251
    • P04K with patterned warming: f.c6.F1850.f19_f19.paleo_ppe.sst_p04k_pat.ens251
    • Abrupt4×CO2: f.c6.F1850.f19_f19.paleo_ppe.sst_prei_04x.ens251
  • Model Version: CAM6_3_026 with additional PaleoCalibr fixes
  • Resolution: 1.9x2.5 (nominal 2° atmosphere/land)
  • Ensemble Size: 251
  • Time Frequencies Saved: Monthly and daily
  • Machine: NWSC Cheyenne and Derecho
  • Compsets: F1850

Data Acquisition

  • On the NWSC computing storage at:

    /glade/campaign/collections/rda/data/d651038/

  • On NSF NCAR RDA: d651038

Contact

Please direct questions/comments about this page to:

Jiang Zhu

Project Scientist

email