CESM2 contains several subversions as described on the CESM2 Release Webpage. CESM2.0 and CESM2.1 are consistent with CMIP6 simulations, while CESM2.2 contains a number of updates that will give different results from previous versions. CESM2.2 is a "functional" release, and not all available compsets and configurations have been scientifically validated. When building some combinations of resolution and compsets you may need to include the switch "--run-unsupported" when creating a case. The default chemical mechanism for CAM-chem in CESM2 is the MOZART-TS1 chemistry (Emmons et al., 2020) with MAM4 aerosols and a VBS-SOA scheme (Tilmes et al., 2019).
CESM2.2 contains MUSICA-V0. CESM2.2 also includes an updated scavenging of aerosols in convective clouds. The MOZART-TS2 chemical mechanism (Schwantes et al., 2020) is available. Both MOZART-TS1 and -TS2 now include the NOx-dependent VBS-SOA scheme described in Jo et al. (2020).
See the CESM2.1 Quickstart Guide or the CESM2.2 Quickstart Guide for information on downloading the model code.
The definitions of CESM compsets (component sets, i.e., configurations) can be found here: http://www.cesm.ucar.edu/models/cesm2/cesm/compsets.html. Current CAM-chem compsets start with "FC". More information on the CESM2.2 CAM-chem compsets is available on the MUSICA-V0 wiki. Compsets that include "ts2" use the MOZART-TS2 chemical mechanism published in Schwantes et al. (2020). Compsets with "nudged" use the physics-side nudging, as described in the CAM User's Guide. Spectral Element resolutions are now available: "ne30" is approximately 1-deg resolution, ne30pg3 is approximately 1-degree with CSLAM (Conservative Semi-Lagrangian multi-tracer transport scheme). More information on supported grids is on the CESM2 grids webpage.
See MUSICA wiki for more information about compsets appropriate for the CONUS regionally refined grid.
| CompSet | Chemistry | Meteorology | Other Components | Default Start Date | Default Emissions | Possible Resolutions | Comments |
|---|---|---|---|---|---|---|---|
| FCnudged | TS1 | nudging to MERRA2 on 32 Levels | prescribed SST prescribed LAI(1) | Jan 2010 | CMIP6 | f09_f09_mg17 | MERRA2 available 1990-present; |
| FCts2nudged | TS2 | nudging to MERRA2 on 32 Levels | prescribed SST prescribed LAI(1) | Jan 2010 | CMIP6 | f09_f09_mg17 | MERRA2 available 1990-present |
| FCHIST | TS1 | CAM6, transient | prescribed SST prescribed LAI(1) | Jan 2010 | CMIP6 | f09_f09_mg17 ne30_ne30_mg17 ne30pg3_ne30pg3_mg17 | Appropriate for simulations from 1850 to 2015 |
| FC2010 | TS1 | CAM6, repeats year 2010 | prescribed SST prescribed LAI(1) | Jan 2010 | CMIP6 | f09_f09_mg17 ne30_ne30_mg17 ne30pg3_ne30pg3_mg17 | Calendar: NO_LEAP |
| FCSD | TS1 | Specified Dynamics MERRA2 on 56 Levels | prescribed SST prescribed LAI(1) | Jan 2005 | CMIP6 | f09_f09_mg17 | FCnudged is now recommended instead of FCSD |
| FCfireHIST | TS1 | CAM6 | prescribed SST | Jan 1995 | interactive fire emissions from CLM; CMIP6 anthro | f09_f09_mg17 | *** do not use without consulting ACOM scientists *** Currently default includes offline fire emissions, too. |
(1) Uses satellite phenology (bgc sp) from observed present day LAI
Most recent SST file to point to:
$DIN_LOC_ROOT/atm/cam/sst/sst_HadOIBl_bc_1x1_1850_2021_c120422.nc