The Grid Analysis and Display System (GrADS) analyses and displays gridded data. GrADS can ingest netCDF-format files by three methods, the simplest of which is with the routine "sdfopen" (GrADS documentation). Files that are compliant with the COARDS (Cooperative Ocean / Atmosphere Research Data Service) standards can be ingested with "sdfopen filename.nc" (no quotes). If this doesn't work for you, it may be because the time variable is written in different time units than what sdfopen has been written to handle. sdfopen used to only take files where time was written in hours. I am not sure if it is more flexible now.
In the example that follows, the input file to be read is entitled "slp.mon.mean.nc".
To open a file, once you are in GrADS, just type: ->The GrADS WWW home page documents the GrADS commands, and there is a short and useful tutorial.sdfopen slp.mon.mean.ncThis command will open the file, and give you the ranges of the dimensions of the file. To see what the variable name is, type ->q file 1and it will return File 1 : monthly mean slp from the NCEP Reanalysis Descriptor: slp.mon.mean.nc Binary: slp.mon.mean.nc Type = Gridded Xsize = 144 Ysize = 73 Zsize = 1 Tsize = 752 Esize = 1 Number of Variables = 1 slp 0 t,y,x Sea Level Pressure The variable name is "slp." To plot the second month of data ->set t 2->d slp