What's New

The main purpose of this tag is to provide the community with a scientifically validated low-resolution version of the CESM1.0 model. This model also includes enhancements and bug fixes, as noted below and in the "Answer-Changing Features" section.

See also the Model Output Diagnostic Plots page for the low-resolution diagnostics and the Model Output Data page for the low-resolution model data.

  • atmosphere/CAM-5.0
    • Tuning mods for Eulerian T31 resolution used in paleoclimate simulations.
    • Fix for the FV div4 filter. This filter is only turned on by default for 1/2 deg and higher resolution grids, so this change only affects answers for those resolutions.
    • Set the lower boundary values of GHGs using the WACCM lower boundary file for all prognostic GHG chemistry schemes. This changes answers beyond roundoff for WACCM runs and for trop_mozart. It doesn't affect trop_mam3 or the superfast_chem schemes.
    • Fix to column pairing algorithm in phys_grid. The bug would cause load balance problems, but not affect answers.
    • Fix the prescribed GHG dataset for cam5 use case. Enables historical run to go through the end of 2005. This changes answers beyond roundoff for cam5 historical runs.
    • Include workaround for extremely slow compilations with the intel compiler.
    • Corrected the default settings for cam5 simulations at resolutions other than 1.9x2.5. This changes answers beyond roundoff for all cam5 simulations except those done at 1.9x2.5.

  • land/CLM
    • Add a new initial condition file for T31 support.
    • Turn ice_runoff to off for T31.
    • Add ndepmapalgo to namelist:
      • ndepmapalgo = Mapping method from Nitrogen deposition input file to the model resolution. The mapping method can be bilinear,nn,nnoni,nnonj,spval,copy; the default is bilinear.
    • Add U10 field to driver and history files (for dust, old U10 field renamed to U10_DUST).
    • Add new single point options for mksurfdata (to override vegetation and soil types).
    • Change some configure options, add -sitespf_pt option to setup urban test sites correctly.

  • ice/CICE
    • Parameters for the low-resolution (gx3v7) ice model have been modified, and solutions produced with these settings have been scientifically validated.

  • ocn/POP2
    • Parameters for the low-resolution (gx3v7) ocean model are scientifically valid.
    • Minor improvements have been made to POP2 netCDF tavg history fields.

  • driver
    • In previous versions, the epbal factor (when activated) was applied to precip, but not runoff. In the cesm1_0_2 release, this problem has been corrected: the epbal factor is now applied to runoff, too.

  • share code
    • A workaround for the shr_scam_mod.F90 build issue has been implemented.

  • scripts
    • Added support for T31_g37.
    • Moved ${COMP}_NCPL to env_conf.xml.
    • Added START_TOD to env_run.xml.
    • Updated library module to allow CESM1 to build on kraken.
    • Set CCSM_CO2_PPMV for all 2000 compsets to 367.0, which changes answers.
    • Parallelized the archiving scripts for faster turnaround of archiving tasks.

  • data, dead, and stub models
    • The stub and dead models are unchanged.
    • The dlnd and docn models are unchanged.
    • The datm and dice models were updated for compatability with share code.