Processing NASA DAYMET files with CDO

Hi all,

I'm wondering if others can confirm that CDO works as expected when processing DAYMET files [[http://daymet.ornl.gov/]], and your experience with deriving climate indices with these files using CDO.

What I want to accomplish isn't overly complex. I'm taking daily gridded tmin, tmax, and precipitation files, and I would like to get monthly averages for each with the intention of calculating similar "bioclimatic" variables as those used in WorldClim raster sets [[http://www.worldclim.org/bioclim]], using something like "dismo" [[http://cran.r-project.org/web/packages/dismo/index.html]] in R. Perhaps that last part is something I can avoid with CDO?

I've already run a test using cdo monmean and the results appeared to what I'm after (a file with 12 bands instead of 365).

I found the speed impressive (for a guy used to ArcGIS raster processing speeds).

cdo monmean: Processed 18572295 values from 2 variables over 365 timesteps. ( 1.43s )

In any case, I found CDO so easy to use and fast. So much so that I don't quite believe it! Hopefully it's not too good to be true.

Thanks in advance!

Replies (1)

RE: Processing NASA DAYMET files with CDO - Added by Dennis Duro about 10 years ago

Hmmm...actually, while the output appears to be expected (still verifying), it seems as if CDO strips out variable names as indicated here [[https://code.zmaw.de/projects/cdo/wiki#Lost-netCDF-variablesdimensions-after-processing-with-CDO]]

Is there a way to avoid this? Subsequent processing of the resulting NetCDF file processed with CDO is problematic since the variable names are missing. The link above suggests:

All coordinate variables and dimensions which are not assigned to a data variable will be lost after processing with CDO!

Is there a way to ensure that all coordinate variables and dimensions are assigned to a data variable? Not sure how this would be done.

For reference, an example of the kind of file I'm processing can be downloaded from here:

[[http://daymet.ornl.gov/thredds/fileServer/allcf/2009/12112_2009/tmax.nc]]

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