percentile-based eca indices
Added by Natalia Tatarinova about 11 years ago
Hello cdo,
I'd like to calculate a percentile-based indice, for example TN90p:
cdo eca_tn90p tnfile tnn90file ofile
How do i calculate tnn90file ?
If we calculate it with daypctl?
Can you give me an example, please?
Thank you.
Best regardes,
Natalia
Replies (7)
RE: percentile-based eca indices - Added by Ralf Mueller about 11 years ago
I guess, daypctl is correct, but I'm not an expert in these indices.
RE: percentile-based eca indices - Added by Natalia Tatarinova about 11 years ago
In fact, i think that we must use here not daypctl, but timpctl!
timpctl needs 3 inputs:
- ifile1: where we want to compute the Xth percentile
- ifile2: the result of timmin
- ifile3: the result of timmax
But why need to know min and max values (the results of timmin and timmax) to calculate a percentile?..
If anybody has an idea?
Thanks.
Natalia
RE: percentile-based eca indices - Added by Uwe Schulzweida about 11 years ago
The percentile algorithm for timpctl uses histograms with minimum and maximum bounds given in ifile2 and ifile3, respectively.
I'm also not an expert in these indices but I think the 90th percentile TNn90 of daily minimum temperatures of the reference period have to be computed with runpctl,90,5.
RE: percentile-based eca indices - Added by Natalia Tatarinova about 11 years ago
Hi,
Thank you for your response.
I calculated TNn90 with runpctl.
But after, when i calculate eca_tn90p:
cdo eca_tn90p tnfile tnn90file ofile
(where:
tnfile: time series of daily min (period: 1850-2005)
tnn90file: the result of runpctl for the reference period: 1960-1990 )
I got the following error:
Input streams have different number of time steps!
But how it is possible they have the same number of steps?
So, it is still not clear.
If there are the cdo experts in this kind of indices, could you forward my question, please?
Best regards,
Natalia
RE: percentile-based eca indices - Added by Natalia Tatarinova about 11 years ago
Normally, tnn90file must contain TNn90 which is calculated as the 90th percentile of daily minimum
temperatures of a five day window centred on each calendar day of a given climate reference period.
It means that in output TNn90 must have the following dimentions (366, d2, d3).
But rupctl doesn't do it like this...
Natalia
RE: percentile-based eca indices - Added by Arne Kriegsmann about 11 years ago
Hi Natalia,
have you tried
cdo ydrunpctl,10,5 BASE -ydrunmin,5 BASE -ydrunmax,5 BASE PCTL10
?
Arne
RE: percentile-based eca indices - Added by Natalia Tatarinova almost 11 years ago
Hi Arne,
Thank you for response!
Yes, i tried:
cdo ydrunpctl,10,5 BASE -ydrunmin,5 BASE -ydrunmax,5 BASE PCTL10
But after, when i do:
cdo eca_tg10p TG PCTL10 TG10P
I get again:
Input streams have different number of time steps!
Natalia