CDO

Hi,

I have daily rainfall data (30 years continously) Is it a time series data (my data)

I guess so.

or I have to prepare a time series data from my daily data (30 years).

daily data IS a time series; it all depends on how you define your statistics (daily/monthly/yearly) - it's all time series.

I want to calculate Consecutive dry days index per time period

since you have the daily data - just use that as the input file for the cdo operator

Cheers,
J.

Hi,
Thank you for your reply.
So, I can use the daily data file directly as a input file for calculation of Consecutive dry days index per time period.
Means the CDO operator is like this cdo eca_cdd rrfile ofile.
Here rrfile means my daily data file as an input file (as you mentioned).

If it is not please let me know...

Cheers
KOTI

Hi,
If I try like tht I am getting problem.
Here I am sending my daily data file.
Please try with this once.

cheers
koti

Hi,

The "eca_cdd" operator works as (from CDO documentation):

+++++++++++++++++++++++++++++++++++++
usage: eca_cdd[,R] ifile ofile

Let ifile be a time series of the daily precipitation amount RR, then the largest number 
    of consecutive days where RR is less than R is counted. R is an optional parameter with 
    default R = 1 mm. 
+++++++++++++++++++++++++++++++++++++

Now, as mentioned in the documentation, the default value of R is 1mm. BUT the maximum value of your data is 0.00321296 (from "cdo -output -fldmax -timmax pr_day_bcc-csm1-1_historical_r1i1p1_1971-2000.nc")

Your data is "precipitation_flux" in "kg m^-2 s^-1", may be you should convert to daily precipitation sum or change the units and it will work.

Cheers,
J.

Hi,
Thanks alot, its working.
And I have one more doubt regarding this.
How I will create only seasonal data from this daily data
i.e My data is daily with 30 years, means each year it has 365 days like that 30 years.
And i want only seasonal data (june,july,august,september) of each year like that 30 years as a single data set (daily).
Will you please guide me.

Thanks once again
KOTI

And i want only seasonal data (june,july,august,september)

try: cdo -selmon,6,7,8,9 infile outfile

also have a look at,

1. Multi-year monthly statistical values: https://code.zmaw.de/embedded/cdo/1.5.4/cdo.html#x1-4110002.8.29

2. Multi-year seasonal statistical values: https://code.zmaw.de/embedded/cdo/1.5.4/cdo.html#x1-4220002.8.31

Will you please guide me.

I don't feel qualified enough to guide someone

There are tons of CDO operators but you have to try!

Cheers,
J.

Hi,
Thanks you for you kind reply,
But, I want seasonal daily data for all 30 years.
Suppose for example for the year 1971 we have 122 days for the season (means june,july,august,september)
and for 1972 again we have 122 and 1973 we have 122 like that.
I want to join each year seasonal daily like 1971+1972.....2000 and we get finally one seasonal data file one for these months.
And the time steps are as follows: for 1971 it is 122 and for 1972 it will start with 123 like that upto 2000...
Please help to me in this regard.
Is there any cdo operator for doing this, I search but I could not get....

Cheers
KOTI

have you really tried:

cdo -selmon,6,7,8,9 pr_day_bcc-csm1-1_historical_r1i1p1_1971-2000.nc outfile.nc

and please check, for example:

cdo sinfov -seltimestep,122 outfile.nc

cdo sinfov -seltimestep,123 outfile.nc

Hi ,
Thank you so much....
It is working nicely....

Cheers
KOTI