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Count precipitation days by month from annual file

Added by Jed Kaplan about 12 years ago

Hello CDO'ers,

I would like to calculate the number of days per month with nonzero precipitation from a file that contains daily precipitation rate values over a whole year. I have seen that with the CDO operator "eca_pd" I can sum up rain days, but if I use this on my file, I can only calculate the annual sum. Is there any way to get what I want with CDO short of extracting each month individually from the original file, processing it, and then having 12 separate files that I would have to reassemble using, e.g., the "mergetime" operator?

The file I am working with is here, in case you would like to experiment yourself.

ftp://ftp.cdc.noaa.gov/Datasets/20thC_ReanV2/Dailies/gaussian/monolevel/prate.2000.nc

Many thanks in advance for your help!

Jed


Replies (2)

RE: Count precipitation days by month from annual file - Added by Jed Kaplan about 12 years ago

Never mind, I wrote a script to do this.

#!/bin/sh

for (( year=1871; year<=1999; year++ ))
do

  echo $year

  curl -O ftp://ftp.cdc.noaa.gov/Datasets/20thC_ReanV2/Dailies/gaussian/monolevel/prate.$year.nc

  echo

  cdo -s -b 32 delname,time_bnds -mulc,86400 prate.$year.nc tmp1.nc

  for (( i=1; i<=12; i++ ))
  do
    m=`printf "%02i\n" $i`
    cdo -s selmon,$i tmp1.nc tmp2.nc 
    cdo -s eca_pd,1 tmp2.nc precmon/$m.nc
  done

  cd precmon

  files=`ls *.nc`

  cdo -s mergetime $files ../wetdays/$year.nc

  rm *.nc

  cd ..

  rm prate.$year.nc tmp1.nc tmp2.nc

done
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