CESM Climate Variability Working Group: CCSM3/CAM3 Experiments
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This page highlights experiments conducted with CCSM3/CAM3 (or earlier model versions) by the Climate Variability working group or CCSM development team. Links are also provided to related CCSM3 integrations. Click on the "Details" links for further information. Answers to Frequently Asked Questions (FAQ) are located below.
Simulations
| Model | Run Type | Res | Short Description |
| CAM3 | Extensions | T85, T42 | Various CAM3 experiments were extended from January 2001 through December 2008 (or 2009) using observed SSTs and/or AR4 A1B forcings (if needed). [details] |
| CAM3 | ARCOGA | T42 | 5 member ensemble forced by climatological SSTs (90S-40N) and time-varying SST/Ice (40N-90N) where the ice coverage data exceeds 10% of the absolute difference between monthly and climatological values, with no radiative forcing; otherwise, climatological values are used. [details] |
| CCSM3 | SRES-A1B | T42 | 40 member ensemble forced by IPCC SRES-A1B scenario forcings from 2000-2061. Stratospheric ozone recovery was included. [details] |
| CAM3 | RADATM | T85 | 5 member ensemble forced by climatological SSTs and time-varying (1950-2000) volcanic, greenhouse gas, aerosol and solar forcings used in the CCSM3 "Climate of the 20th century" integrations. [details] |
| CAM3.3 | Idealized / AMIP | T85 | Eleven unique idealized SST simulations, one control simulation, and one AMIP-style simulation were completed in support of the U.S. CLIVAR Drought Working Group. [details] |
| CAM3 | RADATM | T42 | 10 member ensemble forced by climatological SSTs and time-varying (1950-2000) volcanic, greenhouse gas, aerosol and solar forcings used in the CCSM3 "Climate of the 20th century" integrations. [details] |
| CAM3 | TOGA | T85 | 5 member TOGA ensemble forced by tropical (20N-20S) observed time-varying SSTs from January 1871 through December 1949. Climatological seasonal cycle of SSTs used polewards of 30°, with linear interpolation between 20° and 30°. [details] |
| CAM3 | TOGA | T85 | 5 member TOGA ensemble forced by tropical (20N-20S) observed time-varying SSTs from January 1950 through November 2001. Climatological seasonal cycle of SSTs used polewards of 30°, with linear interpolation between 20° and 30°. [details] |
| CAM3 | TOGA | T42 | 5 member TOGA ensemble forced by tropical (20N-20S) observed time-varying SSTs from January 1950 through September 2001. Climatological seasonal cycle of SSTs used polewards of 30°, with linear interpolation between 20° and 30°. [details] |
| CAM3 | GOGA | T42 | 5 member GOGA ensemble forced by global observed time-varying SSTs from January 1950 through January 2001. [details] |
| CAM3 | GOGA (IPCC) | T42 | 5 member GOGA ensemble forced by global observed time-varying SSTs from January 1950 through December 2000 plus volcanic, greenhouse gas, aerosol and solar forcings used in the CCSM3 "Climate of the 20th century" integrations. [details] |
| CAM3 | GOGA | T85 | 5 member GOGA ensemble forced by global observed time-varying SSTs from January 1950 through December 2000. [details] |
| CAM3 | GOGA (IPCC) | T85 | 5 member GOGA ensemble forced by global observed time-varying SSTs from January 1950 through December 2000 plus volcanic, greenhouse gas, aerosol and solar forcings used in the CCSM3 "Climate of the 20th century" integrations. [details] |
| CAM2 | GOGA | T42 | 15 member GOGA ensemble forced by global observed time-varying SSTs from February 1949 through September 2001. [details] |
| CAM3 | Control | T42 | 200 year control run forced by observed SST (climatological seasonal cycle). [details] |
| CAM3 | Control | T85 | 100 year control run forced by observed SST (climatological seasonal cycle). [details] |
| CCSM3 | Control | T42 | 1000 year control run, fully coupled. [details] |
| CCSM3 | Control | T85 | 700 year control run, fully coupled. [details] |
FAQ
Q1 I do not have access to the mass store or CISL/SCD machines, how should I get the data?
- For requests of post-processed data that are on the smaller side, you can email me here, and I will be happy to copy the data to CGD's ftp site. For all other requests it is suggested that you get an CISL account. You can get that by clicking here.
Q2 I noticed that the runs listed as CAM3 runs used a version of cam called cam2_0_2, and that in the history file names "cam2" is present, are these runs really CAM3 runs?
- Yes, cam2.0.2 is officially CAM3. Recent versions of CAM3 have been named cam3.1.* to avoid this type of confusion. Technically, all versions of cam2.0.2 -> cam3.0 are referred to as CAM3.0, while all versions of cam3.1 are referred to as as CAM3.1. CAM3.1 reproduces the same climate as CAM3.0. Please visit the CAM webpage for more details.
Q3 Some of the post-processed data is in 20-year chunks per netCDF file, how can I merge all these 20-year files together into one file?
- It is suggested that you use the netCDF operators to concatenate the files together. The
operators are available on most CGD/SCD systems. In this case you would use ncrcat, which will concatenate a number of files into one file:
- ncrcat b30.009.cam2.h0.Z3.0400-01_cat_0419-12.nc b30.009.cam2.h0.Z3.0420-01_cat_0439-12.nc b30.009.cam2.h0.Z3.0400-0439.nc
Q4a When I do a ncdump on a CAM3 monthly history file, the date inside the file doesn't match the file name, why?
Q4b When I read a CAM3 file into GrADS, GrADS says that the time is a different time from the file name. Which is correct?
- For monthly history data, the name of the file is always correct. The time in the file (denoted by the variable date) is the model
time that the previous monthly average was calculated. Thus, if the file name is newsstamip31.cam2.h0.1950-01.nc, and the date
variable inside the file is set = 19500201, that file contains the January 1950 monthly average (which was calculated on February 1st, 1950).
For non-monthly history files (ex. daily), let's use the file eul128x256_d63vamip_trpsst_04.cam2.h1.2001-03-15-00000.nc as an example. The first timestep would contain the March 14th daily average for averaged variables, it would contain the March 15th 00Z instantaneous value for instantaneous variables. This can be deduced by looking at the variables time, time_bnds, date, and datesec.
Q5 Is there a reference for the SST dataset that is used for the CAM2/CAM3 AGCM runs?
- Hurrell, J.W., J.J. Hack, D. Shea, J.M. Caron, and J. Rosinski, 2008: A new sea surface temperature
and sea ice boundary data set for the Community Atmosphere Model Journal of Climate: Vol. 21,
pp 5145-5153, DOI: 10.1175/2008JCLI2292.1
The SST dataset is a blended version of the HadISST and Reynolds datasets.
Q6 What programming language is recommended for processing/visualizing CCSM/CAM model data?
- It is recommended that you use NCL. NCL is easy to use, can read in many different types of data (netCDF, HDF4, HDF4-EOS, GRIB, shapefiles, binary and ASCII), runs on most system architectures (Solaris, AIX, IRIX, Linux, MacOSX, Dec Alpha, and Cygwin/X running on Windows), has a regularly updated web page with many example scripts, produces high quality graphics, has a support team, and best of all is free. For a more thorough overview please click here.