[gradsusr] daily anomaly

Mon Sep 10 10:45:24 EDT 2012

Sujata,

Assume the file names for non-leap year & leap year climatology as:
filename.leap.year.climo
filename.non-leap.year.climo

set up soft-links for non-leap years in a do loop as (in cshell) as:

foreach year  (1979 1981 1982 1983 1985 1986 1987 1989 1990 1991)
ln -s filename.non-leap.year.climo  climatology.$year
end

similarly set up soft-links for leap years in a do loop as (in cshell) as:

foreach year  (1980 1984 1988 1992)
ln -s filename.leap.year.climo  climatology.$year
end

add as many non-leap/leap years as necessary within the parentheses for
the data
period in your analysis. Note: the newly created common (for both leap &
non-leap year)
climatology file name for each YEAR of analysis is:
climatology.YEAR

now for the grads control file use for dset as:

dset climatology.%y4
options template
....
....
...

I hope this helps. If it is still not year, please talk to someone
who knows unix and grads. I am myself not an expert in these
things either :-)

Muthu

On Mon, Sep 10, 2012 at 2:38 AM, Sujata Mandke <amin at tropmet.res.in> wrote:

> Respecetd Muthuvel sir,
>
>  Thanks a lot for help.
>
>  I need further assistance in this problem, as I understood
>  your suggestions partly. Follows the details of the part of
>  your suggestions that I understood and the part that
>  is not clear.
>
> > Create two different climatology data sets, one for
> > and 365 days another for leap year with 366 days.
>
>     This is clear.
>
> > Set up repeated soft links for each year of data set respectively
> >to non-leap years and >leap years in analysis period (very easy
> > to do, couple of lines of unix scripts). Create a >single grads
> > ctl file or all these climo years.
>
>     I do not  know how to create soft links (in unix scripts)
>      and how to create a single grads ctl file for two separate datasets
>     (one for non-leap years climo and other for leap years climo).
>
> >Open up your total field control field and this climo control file,
> > then you are in business. We did like this at CPC more than
> > two decades ago and we continue to do like this now as we work
> > with daily cdas fields. I hope this helps. Please email me
> > separately if you need further assistance. Good day!
>
>      Opening two 'ctl' files and calculating difference between
>  control fields and climo field looks easier to do in grads script.
>
>
> Regards and bets wishes
> Dr. Sujata Mandke
> Scientist,IITM,Pune-8
>
> ----- Original Message -----
> From: Muthuvel Chelliah <muthuvel.chelliah at noaa.gov>
> To: GrADS Users Forum <gradsusr at gradsusr.org>
> Sent: Fri, 07 Sep 2012 20:22:55 +0530 (IST)
> Subject: Re: [gradsusr] daily anomaly
>
> Sujata,
> Create two different climatology data sets, one for 365 days and another
> for leap year with 366 days.
> Set up repeated soft links for each year of data set respectively to
> non-leap years and leap years
> in analysis period (very easy to do, couple of lines of unix scripts).
> Create a single grads ctl file
> for all these climo years. Open up your total field control field and this
> climo control file, then you are in business. We did like this at CPC more
> than two decades ago and we continue to do like this now as we work with
> daily cdas fields. I hope this helps. Please email me separately if you
> need further assistance. Good day!
> Muthu
>
> On Fri, Sep 7, 2012 at 2:52 AM, Sujata Mandke <amin at tropmet.res.in> wrote:
>
> >   Respected Narapusetty Sir,
> >
> >      Thanks for prompt reply and willingness to provide
> >    further assistance in my problem. I will go thorugh your
> >    article and then try to solve the problem.
> >
> >          However, you had solved the problem by
> > calculating climatology. I am having longterm daily
> >  climatology dataset, so there is no need to calculate climatology.
> > Regards
> > Sujata Mandke
> > IITM,PUNE-8,INDIA.
> >
> > ----- Original Message -----
> > From: Balachandrudu Narapusetty <bnarapus at gmu.edu>
> > To: GrADS Users Forum <gradsusr at gradsusr.org>
> > Cc: gradsusr at gradsusr.org
> > Sent: Thu, 06 Sep 2012 20:10:31 +0530 (IST)
> > Subject: Re: [gradsusr] daily anomaly
> >
> > Hi Dr. Sujata,
> >
> > I am happy to see somebody has same problem that I had some time ago. I
> > solved it by estimating the climatology (and thereafter anomalies) using
> > few harmonics.
> >
> > I am sure this article is useful in dealing with your problem:
> >
> > Narapusetty, Balachandrudu, Timothy DelSole, Michael K. Tippett, 2009:
> > Optimal Estimation of the Climatological Mean. J. Climate, 22, 4845–4859.
> > doi: http://dx.doi.org/10.1175/2009JCLI2944.1
> >
> > I am happy to provide further assistance if you have questions.
> >
> > Best regards,
> > Bala
> >
> >
> > ----- Original Message -----
> > From: Sujata Mandke <amin at tropmet.res.in>
> > Date: Thursday, September 6, 2012 7:24 am
> > Subject: [gradsusr] daily anomaly
> >
> > > Dear Grads Users
> > >    I wish to calculate daily OLR anomaly from
> > >  the following datasets.
> > >    I have daily OLR data (netcdf) for the period
> > >   1Jun1974-31May2012. Also long term daily OLR
> > >   climatology (netcdf) data for 365 days.
> > >
> > >   As such writting script for calculating daily
> > >  anomaly is very simple. But how to tackle following
> > >    two problems while calculating anomaly
> > >
> > > (i) Actual data is on Gregorian(real) calendar
> > >    and thus has data for 366 days in leap years.
> > > (ii) What to do with missing values?
> > >
> > > Does anybody has grads script to calculate daily
> > > anomaly by taking care of above two problems.
> > > Regards
> > > Dr. Sujata Mandke,Scientist,
> > > IITM,PUNE-8,INDIA.
> > > _______________________________________________
> > > gradsusr mailing list
> > > gradsusr at gradsusr.org
> > > http://gradsusr.org/mailman/listinfo/gradsusr
> > >
> >
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> >
> >
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>
>
>
> --
>
> ------------------------------------------------------------------
> Dr.Muthuvel Chelliah, eMail:Muthuvel.Chelliah at noaa.gov
> Rm.3008, Climate Prediction Center, Ph:(301) 683-3393
> NCEP/NWS/NOAA/U.S.Dept.of Commerce,
> 5830, University Research Court, NCWCP
> College Park, MD 20740.
>
>
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-- 

------------------------------------------------------------------
Dr.Muthuvel Chelliah, eMail:Muthuvel.Chelliah at noaa.gov
Rm.3008, Climate Prediction Center, Ph:(301) 683-3393
NCEP/NWS/NOAA/U.S.Dept.of Commerce,
5830, University Research Court, NCWCP
College Park, MD 20740.
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