Re: Concatenate files in NCL

Hi Waqar,
See method #1 here:
http://www.ncl.ucar.edu/Applications/o-netcdf.shtml

Note the following code:

  ; make time an UNLIMITED dimension ; recommended for most applications
    *filedimdef* <http://www.ncl.ucar.edu/Document/Functions/Built-in/filedimdef.shtml>(ncdf,"time",-1,True)

That should set the time dimension to unlimited, allowing you to
concatenate the file..

If that does not solve the issue please respond to ncl-talk.
Adam

On 01/29/2014 01:37 PM, Waqar Younas wrote:
> Hi everyone,
> Does anyone know about how to concatenate different nc files into one
> single file in NCL? I have observed daily SST from 1981 to 2002 and
> the dimensions are time,lat,lon. I first regrid each file to 2.5 by
> 2.5 and then tried to concatenate them in NCO (ncrcat). But NCO says
> that the individual file does not have record dimension in it. I
> cannot use ncecat because my time is different for each file. The leap
> year has 366 days and other years have 365. Surprisingly, When i
> concatenate original files (without regridding, 0.5 by 0.5), it works.
> But when i re grid and then concatenate it did not.
> The ncdump of original file is
>
> netcdf sst.day.mean.1982.v2 {
> dimensions:
> time = UNLIMITED ; // (365 currently)
> lat = 720 ;
> lon = 1440 ;
> variables:
> double time(time) ;
> time:long_name = "Time" ;
> time:units = "days since 1800-01-01 00:00:00" ;
> time:actual_range = 66474., 66838. ;
> time:delta_t = "0000-00-01 00:00:00" ;
> time:avg_period = "0000-00-01 00:00:00" ;
> time:axis = "T" ;
> float lat(lat) ;
> lat:long_name = "Latitude" ;
> lat:standard_name = "latitude" ;
> lat:units = "degrees_north" ;
> lat:actual_range = -89.875f, 89.875f ;
> lat:axis = "Y" ;
> float lon(lon) ;
> lon:long_name = "Longitude" ;
> lon:standard_name = "longitude" ;
> lon:units = "degrees_east" ;
> lon:actual_range = 0.125f, 359.875f ;
> lon:axis = "X" ;
> short sst(time, lat, lon) ;
> sst:long_name = "Daily Sea Surface Temperature" ;
> sst:units = "degC" ;
> sst:actual_range = -1.8f, 34.48f ;
> sst:valid_range = -300s, 4500s ;
> sst:unpacked_valid_range = -3.f, 45.f ;
> sst:missing_value = 32767s ;
> sst:scale_factor = 0.01f ;
> sst:add_offset = 0.f ;
> sst:precision = 2s ;
> sst:dataset = "NOAA High-resolution Blended Analysis" ;
> sst:var_desc = "Sea Surface Temperature" ;
> sst:level_desc = "Surface" ;
> sst:statistic = "Mean" ;
> sst:parent_stat = "Individual Observations" ;
>
> // global attributes:
> and for regrided files are
>
> netcdf obs_sst_1982_regrided_90S_90N_1 {
> dimensions:
> time = 365 ;
> lat = 73 ;
> lon = 144 ;
> variables:
> float sst(time, lat, lon) ;
> sst:_FillValue = 32767.f ;
> sst:_FillValue_original = 32767s ;
> sst:parent_stat = "Individual Observations" ;
> sst:statistic = "Mean" ;
> sst:level_desc = "Surface" ;
> sst:var_desc = "Sea Surface Temperature" ;
> sst:dataset = "NOAA High-resolution Blended Analysis" ;
> sst:precision = 2s ;
> sst:add_offset = 0.f ;
> sst:scale_factor = 0.01f ;
> sst:unpacked_valid_range = -3.f, 45.f ;
> sst:valid_range = -300s, 4500s ;
> sst:actual_range = -1.8f, 34.48f ;
> sst:units = "degC" ;
> sst:long_name = "Daily Sea Surface Temperature" ;
> sst:Fill_Value = 32767s ;
> double time(time) ;
> time:long_name = "Time" ;
> time:units = "days since 1800-01-01 00:00:00" ;
> time:actual_range = 66474., 66838. ;
> time:delta_t = "0000-00-01 00:00:00" ;
> time:avg_period = "0000-00-01 00:00:00" ;
> time:axis = "T" ;
> double lat(lat) ;
> lat:units = "degrees_north" ;
> lat:long_name = "latitude" ;
> double lon(lon) ;
> lon:units = "degrees_east" ;
> lon:long_name = "longitude" ;
> }
>
> The difference in is time dimension where Time="UNLIMITED" // 365
> currently
> whereas for regrid file it is
> Time = 365
>
> --
> Best Regards
>
> Waqar Younas
> PhD Candidate
> Natural Resources and Environmental Studies (NRES)
> University of Northern British Columbia (UNBC)
> Canada
>
>
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-- 
______________________________________________________________
Adam Phillips                                asphilli@ucar.edu
NCAR/Climate and Global Dynamics Division       (303) 497-1726
P.O. Box 3000				
Boulder, CO 80307-3000    http://www.cgd.ucar.edu/staff/asphilli

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Received on Wed Jan 29 14:05:01 2014