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creating input files for Climate Indices (e.g. TGn90)

Added by Laura Brown almost 7 years ago

Hello,
I'd like to use the Climate Indices but am unsure as to how to create the input files required by some of the operators.
For example, I'd like to use the ECAHWFI - Warm spell days index w.r.t. 90th percentile of reference period operator for the summer season of 30 climate date files. One of the two input files is described as follows: "TGn90 is calculated as the 90th percentile of daily mean temperatures of a five day window centred on each calendar day of a given climate reference period."

I'm wondering if this set of commands generates the required TGn90:
cdo selmon,6,7,8 -timselmin,5 infile minoutfile
cdo selmon,6,7,8 -timselmax,5 infile maxoutfile
cdo selmon,6,7,8 -timselpctl,90 inflie minoutfile maxoutfile TGn90

I'm also wondering if this is the correct set of commands to calculate the heat wave duration:
cdo eca_hwdi -selmon,6,7,8 tasmax_1960-1991.nc -selmon,6,7,8 -runmean,5 tasmax_1960-1991.nc HeatW_CanESM2_70s.nc
my out put returns:
  1. date value name
    1990-08-31 0 heat_wave_duration_index_wrt_mean_of_reference_period
    1990-08-31 0 heat_waves_per_time_period
    regardless of the climatic period (e.g. 2011-2040, 2041-2070, 2071-2100) so I'm thinking I've made an error.

Thank you for your help.


Replies (1)

RE: creating input files for Climate Indices (e.g. TGn90) - Added by Karin Meier-Fleischer almost 7 years ago

Hi Laura,

you have to use the selmonth operator if you want to select more than one month.

cdo selmonth,6,7,8 -timselmin,5 infile minoutfile
cdo selmonth,6,7,8 -timselmax,5 infile maxoutfile
cdo -timselpctl,90 infile minoutfile maxoutfile TGn90

or in one command line call

cdo -timpctl,90 infile -selmonth,6,7,8 -timselmin,5 infile -selmonth,6,7,8 -timselmax,5 infile TGn90

The date of the heat wave duration data is the date of the last contributing timestep in tasmax_1960-1991.nc.

Bye,
Karin

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