CESM2-CISM2 Transient Global Climate and Greenland Ice Sheet for the Last Interglacial (TransientLIG)
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.
- Simulation protocols: details can be found in Sommers et al. 2021.
- Simulation Names:
- 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
Output is available on the NWSC computing storage at /glade/campaign/cesm/development/palwg/LastInterglacial/CESM2-CISM2-
To obtain output from the CDG follow these steps:
- Register for a login to the CDG.
- Navigate to the project landing page: https://www.earthsystemgrid.org/dataset/ucar.cgd.ccsm4.CESM2-CISM2-LIGtransient.html
- Scroll down to Child Datasets, click chosen component and time frequency.
- Click chosen ‘Child Dataset’ organized by variable.
- Login to CDG to access download options.
- Choose files to download from the list.
Diagnostics for these simulations can be found here.