Yearly statistics on a period over two calendar years
Added by Pauline Millet over 2 years ago
Hello all,
I'm computing yearly statistics on my data with sometimes a month selection. Up to now the selected period was stretched over the same calendar year (ex: from March to June). I'm now facing the issue where I have to deal with period that are not on the same calendar year, let's say from November to February.
Can I still apply a command like the following one to get my statistics?
cdo -yearsum -select,month=11/2 infile outfile
Or should I proceed twice my yearly stat: first on November and December, then on January and February, and combine them to get the wanted result?
What is the best way to achieve this?
Thanks for your help,
Pauline
Replies (4)
RE: Yearly statistics on a period over two calendar years - Added by Karin Meier-Fleischer over 2 years ago
Hi Pauline,
your selection is the 'season' NDJF and you can use the Seasonal statistical values operators (https://code.mpimet.mpg.de/projects/cdo/embedded/cdo.pdf#subsection.2.8.27) after selecting, as you did or with season=NDJF, compute the sum of the season.
cdo -seassum -select,season=NDJF infile outfile
RE: Yearly statistics on a period over two calendar years - Added by Pauline Millet over 2 years ago
Thanks for your answer Karin! I didn't know about seasstats operators.
How would you process with a period being from 7th of december to 23rd of April?
Something in 2 steps like:
cdo -mergetime -selday,7/31 -selmonth,12 infile -selmonth,1/3 infile -selday,1/23 -selmonth,4 infile tempfile cdo -seassum tempfile outfile
? Or is there a simpler way to do it?
Cheers,
Pauline
RE: Yearly statistics on a period over two calendar years - Added by Pauline Millet over 2 years ago
Karin Meier-Fleischer wrote in RE: Yearly statistics on a period over two calendar years:
Hi Pauline,
your selection is the 'season' NDJF and you can use the Seasonal statistical values operators (https://code.mpimet.mpg.de/projects/cdo/embedded/cdo.pdf#subsection.2.8.27) after selecting, as you did or with season=NDJF, compute the sum of the season.
[...]
Hi Karin,
After trying your solution, it seems like it's not working like I expected.
By applying :
cdo -seassum -select,season=NDJF infile outfile
CDO returns a value per year for November, and another one for December-January-February. I would expect to have one single value returned over November to February.
Any idea on how I could achieve this result?
Cheers,
Pauline
RE: Yearly statistics on a period over two calendar years - Added by Karin Meier-Fleischer over 2 years ago
Hi Pauline,
ah, CDO uses the default season start month which is December. You can change it to November by setting the environment variable CDO_SEASON_START to NOV or just use the following command
cdo -timselsum,4,2 -select,season=NDJF infile.nc outfile.nc
-Karin