i have multiple .nc files (huge sizes). i'd like to save only the surface layer information of all variables. I'm wondering can anyone tell me how to do this in ncl language. i tried as below, following http://research.jisao.washington.edu/data_sets/nco/#return:
ncea -d bottom_top,1,1 -F wrfout_d01_2015-11-01_00:00:00.nc surf_wrfout_d01_2015-11-01_00:00:00.nc -bash: ncea: command not found
Examples of commands: 1) The usefulness of these routines is best demonstrated with an example. We get NCEP / NCAR reanalysis data from NOAA CDC in files where values of the variable, for example, geopotential height, are given for all 17 of the model levels. For simplicity it would be nice to have a file of just 500 mb geopotential height. Creating such a file can be done with: ncea -d level,6,6 -F hgt.mon.mean.nc hgt500.mon.mean.nc where:
"ncea" stands for netcdf ensemble averager "-d level,6,6 -F" says take the average along the "level" dimension, and average from level 6 to level 6. The vertical levels in the NCEP NCAR reanalysis are: 1000, 925, 850, 700, 600, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30, 20, 10 and the 500mb level is the 6th level under FORTRAN-indexing (5th level under C-indexing). The "-F" specfication says to use FORTRAN-indexing.
