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cdo monavg renames some dimensions and changes the timezone associate with time variable

Added by dead lift over 7 years ago

Hi

I have file with daily data 'DataExampleNetCDF2014.nc' and I want to produce a monthly average file for same. I used the monavg operator to produce the monthly averages file 'MonAvg2014.nc':
cdo monavg DataExampleNetCDF2014.nc MonAvg2014.nc

The issue that I note is that:
1) The dimensions in the file have been renamed from

dimensions:
time = UNLIMITED; // (365 currently)
lat = 3;
lon = 1;

to

dimensions:
x = 3;
x_2 = 1;
y = 3;
time = UNLIMITED; // (12 currently)
bnds = 2;

2) The time variable properties like units property have been changed from

double time(time=365);
:units = "days since 2014-01-01 00:00:00.0 +0545";
:time_origin = "2014-01-01 00:00:00";
:long_name = "time";
:_ChunkSizes = 512; // int

to

double time(time=12);
:standard_name = "time";
:long_name = "time";
:bounds = "time_bnds";
:units = "days since 2014-1-1 00:00:00";
:calendar = "standard";
:axis = "T";
:_ChunkSizes = 512; // int

Why is that so. How can I keep the properties mentioned above same.
I am attaching the files herewith.

Regards

Download all files
MonAvg2014.nc (29.6 KB) MonAvg2014.nc
DataExampleNetCDF2014.nc (56.3 KB) DataExampleNetCDF2014.nc

Replies (8)

RE: cdo monavg renames some dimensions and changes the timezone associate with time variable - Added by Ralf Mueller over 7 years ago

Hi!
with the current version 1.7.2 , it looks ok. i think, this was fixed in 1.7.1

hth
ralf

t.nc (46.5 KB) t.nc my results of monavg

RE: cdo monavg renames some dimensions and changes the timezone associate with time variable - Added by dead lift over 7 years ago

Ah ok. Thanks.

But I can't use 1.7.2 as at the moment debian Jessie supports 1.6.4 and getting the latest 1.7.2 breaks some packages. So I am stuck.

RE: cdo monavg renames some dimensions and changes the timezone associate with time variable - Added by dead lift over 7 years ago

If I may ask you, which Linux flavour are u using on which cdo 1.7.2 can be installed without any issues.

RE: cdo monavg renames some dimensions and changes the timezone associate with time variable - Added by Ralf Mueller over 7 years ago

I personally use Arch linux, but you can use any other distro, because there are distro-independant ways to install cdo

IMO, conda and docker provide the easiest installation.

hth
ralf

RE: cdo monavg renames some dimensions and changes the timezone associate with time variable - Added by dead lift over 7 years ago

Hi!

Thanks for recommending version 1.7.2. It did not change the dimensions in the file but it notice some changes in time variable. ":time_origin" is missing and the time zone (+0545) is missing from the ":units" property.

The other issue that I have noticed with the new version(1.7.2) is that the size of the monthly average file is much much bigger than the original source file. The size of source file is around 57 KB but the output file generated is around 4121 KB. Why is that so?

Regards

RE: cdo monavg renames some dimensions and changes the timezone associate with time variable - Added by Ralf Mueller over 7 years ago

without the data, its hard to say. For these small netcdf files, you can use ncdump for text conversion and then use are diff or meld for comparison.

    (1-8/8)