The Transient Last Interglacial dataset contains output from the TransientLIG simulation from 127,000 to 119,000 years before present (127 – 119 ka). This simulation is with the CESM2.1 at the FV1_gx1v6 resolution coupled to CISM2 at 4 km resolution for Greenland. The ice sheet model and the orbital parameters over time (eccentricity, obliquity, and precession) are accelerated - advancing 5 years for each CESM2 year. In CAM6, the surface elevation over Greenland is updated every 10 atmosphere years. Offline coupling of BIOME4 distributions every 500 ice-sheet years allows for incorporation of quasi-dynamic vegetation changes [U.S. Geological Survey data release, https://doi.org/10.5066/P9RPB5KD]. All other forcings (GHGs, aerosols, land-ocean configuration) are kept constant during the TransientLIG simulation. A schematic of coupling between the models in the TransientLIG simulation is shown in this figure. 

The dataset also includes a sensitivity simulation (NoBiome) from 127 – 121 ka illustrating the effects of vegetation. This simulation retains the preindustrial no-Anthro vegetation distribution adopted in the CMIP6-PMIP4 127 ka and 6ka equilibrium simulations with CESM2.1 at the FV1_gx1v6 resolution.

The TransientLIG and NoBiome simulations are initialized from the CMIP6-PMIP4 lig127k simulation with CESM2 [http://doi.org/10.22033/ESGF/CMIP6.7673]. The simulations adopted the initial state of the GrIS from the CESM2-CISM2 JG/BG spinup under pre-industrial climate forcing [https://doi.org/10.26024/4gt3-9r10] [CDG]

Further details are provided in this paper:

  • Sommers, A. N., Otto-Bliesner, B. L., Lipscomb, W. H., Lofverstrom, M.,Shafer, S. L., Bartlein, P. J., Brady, E. C., Kluzek, E. , Leguy, G. , Thayer-Calder, K. , and Tomas, R. A. (2021). Retreat and regrowth of the Greenland Ice Sheet during the Last Interglacial as simulated by the CESM2-CISM2 coupled climate–ice sheet model. Paleoceanography and Paleoclimatology, 36, e2021PA004272. [article]

We kindly ask that you reference the paper above and acknowledge the PaleoclimateWG and supercomputing resources provide by NSF / CISL when presenting results based on these simulations in either oral or written form. 

Project Details:

  • Simulation protocols: details can be found in Sommers et al. 2021.
  • Simulation Names:
    • bg.e21.B1850.f09_g17.LIGtransient_albcorrect_127ka
    • bg.e21.B1850.f09_g17.LIGtransient_126.5ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_126.0ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_125.5ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_125.0ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_125.5ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_125.0ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_124.5ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_124.0ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_123.5ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_123.0ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_122.5ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_122.0ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_121.5ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_121.0ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_120.5ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_120.0ka.002
    • bg.e21.B1850.f09_g17.LIGtransient_119.5ka.002
    • bg.e21.B1850.f09_g71.LIGtransient_albcorrect_nobiome
    • bg.e21.B1850.f09_g71.LIGtransient_albcorrect_nobiome_part2
  • Model Version: CESM2.1
  • Resolution: FV1_gx1v6
  • Years: see Sommer et al. 2021 for details.
  • Ensemble Size: one each
  • Time Frequencies Saved: monthly, daily
  • Machine: NCAR Cheyenne

Data Acquisition:

Output is available on the NSF NCAR Research Data Archive available here. 

Diagnostics:

Diagnostics for these simulations can be found here.