Climate Variability & Change
Working Group CVCWG

CAM5 Prescribed SST AMIP Ensembles

The CVCWG has conducted a number of experiments using prescribed SST and ice forcing within CAM5.2 using the CESM1.1 LENS tag. These experiments are comprised of a total of four 10-member ensembles forced with different observational SST's and ice, and one simulation with prescribed SST's and ice from the CESM1.1 Large Ensemble coupled control. Details on these simulations and instructions for how to download the data can be found below.

We kindly ask that you acknowledge the CVCWG when presenting results based on these ensembles in either oral or written form.

Project Details

  • Simulation Names:
    • Tropical AMIP 10-member ensemble (ERSSTv3b):
        f.e11.FAMIPC5CN.f09_f09.historical.ersstv3b.toga.ensXX
        f.e11.FAMIPC5CN.f09_f09.rcp85.ersstv3b.toga.ensXX, XX = 01-10
    • Tropical AMIP 10-member ensemble (ERSSTv4):
        f.e11.FAMIPC5CN.f09_f09.historical.toga.ensXX
        f.e11.FAMIPC5CN.f09_f09.rcp85.toga.ensXX, XX = 01-10
    • Tropical AMIP 10-member ensemble (ERSSTv5):
        f.e11.FAMIPC5CN.f09_f09.historical.ersstv5.toga.ensXX
        f.e11.FAMIPC5CN.f09_f09.rcp85.ersstv5.toga.ensXX, XX = 01-10
    • Global AMIP 10-member ensemble (ERSSTv4):
        f.e11.FAMIPC5CN.f09_f09.historical.goga.ensXX
        f.e11.FAMIPC5CN.f09_f09.rcp85.goga.ensXX, XX = 1-10
    • Global AMIP with prescribed sst/sea-ice from CESM1-LENS pre-industrial control:
        f.e11.F1850C5CNTVSST.f09_f09.002
  • Model Version: CESM1.1 Codebase | Documentation
  • Resolution: 0.9x1.25_gx1v6 (CESM nominal 1o grid)
  • Years: 1880-2016 (Tropical AMIP ERSSTv3b), 1880-2014 (Tropical AMIP ERSSTv4), 1880-2015 (Global AMIP ERSSTv4), 1880-2017 (Tropical AMIP ERSSTv5), 401-600 (Global AMIP with LENS control sst/ice)
  • Ensemble Size: 10 members (Tropical and Global AMIP ensembles), 1 member (Global AMIP with LENS control sst/ice)
  • Time Frequencies Saved: Monthly, Daily
  • Machine: NCAR:Cheyenne or NCAR:Yellowstone
  • Compsets: FAMIPC5CN (TOGA and GOGA ensembles), F1850C5CNTVSST (AMIP with LENS control sst/ice)

  • Additional Notes: All ensembles use the exact same codebase as the CESM1 Large Ensemble.

    For the Tropical AMIP ensembles SST's from 28S:28N are set to time-varying SST's from ERSSTv3b, ERSSTv4 or ERSSTv5. A transition/linear interpolation zone exists from 28:35 degree latitudes. From 35 degrees polewards full-period climatological SSTs (ERSSTv3b, ERSSTv4, or ERSSTv5)/ice (HadISST1) are set. All simulations are initialized from the first LENS historical member on January 1st, 1880, with each ensemble member receiving a small change in the initial air temperature via namelist setting PERTLIM. All IPCC time-varying forcings were specified in these ensembles, with the exception being that a modified SPARC dataset was used for the ozone forcing.

    For the Global AMIP ensemble ERSSTv4 was used for the SST forcing dataset, and HadISST1 was used for the ice forcing dataset. All CMIP5 time-varying external, natural and anthropogenic forcings were specified in these ensembles, with the exception being that a modified SPARC dataset was used for the ozone forcing.

    For the Global AMIP forced with prescribed sst/sea-ice from the CESM1-LENS pre-industrial control, years 401-600 were used from the pre-industrial control for the sst and sea-ice forcings. No other time-varying forcings were applied.

Data Acquisition

Most simulations are available on both the NCAR Climate Data Gateway (web-access) and the NCAR system casper (NCAR-internal). The F1850C5CNTVSST (AMIP with LENS control sst/ice) simulation is only available via casper access.

  • NCAR-internal (access via NCAR machine casper)
    • Tropical AMIP 10-member ensemble (ERSSTv3b), and Tropical AMIP 10-member ensemble (ERSSTv5), Tropical AMIP 10-member ensemble (ERSSTv4): /glade/collections/cdg/data/CAM_prescribed_SST/f.e11.FAMIPC5CN.f09_f09.hist-rcp85.toga/
    • Global AMIP with prescribed sst/ice from CESM1-LENS pre-industrial control: /glade/campaign/cesm/collections/cesmLE/CESM-CAM5-BGC-LE/
    • Global AMIP GOGA 10-member ensemble (ERSSTv4): /glade/collections/cdg/data/CAM_prescribed_SST/f.e11.FAMIPC5CN.f09_f09.hist-rcp85.goga/

  • web-access
    The following are step by step directions on how to download this data from the Climate Data Gateway.
    1. Proceed to the CAM5 Prescribed SST AMIP Ensembles.
    2. Scroll to the bottom of that page under Child Datasets, and click on Tropical CAM5 Prescribed SST AMIP Ensembles (for tropical AMIP simulations) or Global CAM5 Prescribed SST AMIP Ensembles (for global AMIP simulations).
    3. Scroll to the bottom of that page under Child Datasets, and click on the component and time frequency you are interested in.
    4. The files are organized by variable, listed at the end of each link. Click on the variable you are interested in.
    5. Click on the Download Options button. At this point, if you have not logged into the Climate Data Gateway you can do so now. If you have not registered before, registration is free and quick.
    6. Upon logging in you will see a file listing. Once you have identified a file that you would like to download, click on the check box to the left of the file name. Note that you can select multiple files on this page at once. (However, one cannot select/download multiple files across variables at once.) When you are finished selecting files, scroll to the top (or bottom) of the page and click on the Download Options for Selection box.
    7. Click the Request File Transfer from Archive, and choose whether to use a Curl or Wget script to download your selected data.