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[NOAA bullet] Where can I find land/sea mask fields for the CM2.X model grids?  

If you are interested in GFDL's CM2.X atmosphere and/or land model output, then you should be familiar with the IPCC Table O1b time-independent 2-d land surface data (longitude, latitude) files. A listing of our version of that table is found [ Here ].

Variable sftlf (land_area_fraction) is available both at the IPCC/PCMDI WG1 archive and on GFDL's Data Portal. On the GFDL Data Portal this information is found in netCDF files found in the land/static subdirectories for all 20 experiments. The sftlf (land_area_fraction) information is identical for all CM2.X experiments.

For example, on the GFDL Data Portal you may point your web browser to the directory http://nomads.gfdl.noaa.gov/dods-data/gfdl_cm2_1/CM2.1U-D4_1860-2000-AllForc_H2/pp/land/static/ ...and download the file sftlf_A1.static.nc (a 59KB netCDF file that has been processed in accordance with PCMDI's CMOR program.)

If you are performing analyses using CM2.X ocean and/or sea ice model output stored on the model's native tripolar grid, you should become familiar with our CM2.X model ocean and sea ice grid information web page.

In addition to providing some basic information about the tripolar grid used in the CM2.X ocean and sea ice model components, the CM2.X model ocean and sea ice grid information web page contains links to other sources of grid relevant information, including our own grid_spec_cm2_ocean_tripolar.nc netCDF file. We believe that many users will find the grid_spec_cm2_ocean_tripolar.nc file useful when analyzing CM2.X ocean and sea ice model output.

Concerning land/sea masks, in the grid_spec_cm2_ocean_tripolar.nc netCDF file the variable named wet is a simple 2D (surface latitude longitude) land/sea mask on the ocean's tracer grid. As mentioned in the documentation, the CM2.X ocean and sea ice model components use a staggered B-grid arrangement.

If a land/sea mask for the ocean or sea ice model's velocity grid is desired, one can use the kmu field (it contains the depths on the velocity grid points) to generate 2-D surface velocity grid land/sea mask. A kmu depth of 0.0 indicates land and a kmu value >0.0 indicates ocean. Doing the same for the tracer depths stored as variable kmt, one should recover the wet field.

Questions related to the GFDL CM2.x models may be directed to…


[email GFDL.Climate.Model.Info at noaa dot gov] 
last modified: June 24 2019.