[ferret_users] Problem in preparing monthly climatology using multiple netcdf files

["sreejith k.s" <jithu9907@xxxxxxxxx>]

Dear all,
I am facing some problem in preparing monthly climatoloy using around
120 files covering 10 years.

1) Please see the files as shown below.
SODA_2.2.4_187101.cdf
SODA_2.2.4_187102.cdf
SODA_2.2.4_187103.cdf
..................................................
..................................................
..................................................
SODA_2.2.4_188012.cdf

2) For example, the "ncdump -h" command for one of these files will
give the following result.

netcdf SODA_2.2.4_187312 {
dimensions:
        lon = 720 ;
        lat = 330 ;
        depth = 40 ;
variables:
        float temp(depth, lat, lon) ;
                temp:long_name = "TEMPERATURE" ;
                temp:units = "deg. C" ;
                temp:_FillValue = -9.99e+33f ;
        float salt(depth, lat, lon) ;
                salt:long_name = "SALINITY" ;
                salt:units = "g/kg" ;
                salt:_FillValue = -9.99e+33f ;
        float u(depth, lat, lon) ;
                u:long_name = "ZONAL VELOCITY" ;
                u:units = "m/sec" ;
                u:_FillValue = -9.99e+33f ;
        float v(depth, lat, lon) ;
                v:long_name = "MERIDIONAL VELOCITY" ;
                v:units = "m/sec" ;
                v:_FillValue = -9.99e+33f ;
        float w(depth, lat, lon) ;
                w:long_name = "VERTICAL VELOCITY" ;
                w:units = "m/sec" ;
                w:_FillValue = -9.99e+33f ;
        float taulat, lon) ;
                taux:long_name = "TAUX" ;
                taux:units = "N/m^2" ;
                taux:_FillValue = -9.99e+33f ;
        float tauy(lat, lon) ;
                tauy:long_name = "TAUY" ;
                tauy:units = "N/m^2" ;
                tauy:_FillValue = -9.99e+33f ;
        float ssh(lat, lon) ;
                ssh:long_name = "SEA SURFACE HEIGHT" ;
                ssh:units = "m" ;
                ssh:_FillValue = -9.99e+33f ;
        double lon(lon) ;
                lon:units = "degrees_east" ;
        double lat(lat) ;
                lat:units = "degrees_north" ;
        double depth(depth) ;
                depth:units = "meters" ;
                depthositive = "down" ;

// global attributes:
                :title = "SODA 2.2.4, 1871-2008 Assimilation Run" ;
                :released = "July 20, 2010" ;
                ata_timestamp = "12-1873" ;

The point to be noted here is that there is no time axis in these
files (as it shows only lat,lon and depth). Because of this, merging
these files using "cdo" command - "cdo -r
mergetime" is found to be not working.

Hence I am interested to know two things.
1) How to merge/append all these 120 files into a single file and that
should also give the time axis as time = 120
2) After getting the appended file how to prepare monthly climatology
using the appended file.
3) Is there any other way of preparing the monthly climatology of
above 120 monthly files without going to the step of "creating an
appended data file"?

If anybody know a work around, please help me.

Thanks in advance

Sreejith.

-- 
K. S. SREEJITH
CSIR-JRF, Ph.d Scholar
Centre for Ocean, River, Atmosphere and Land Sciences
Indian Institute of Technology, Kharagpur
West Bengal