[RegCNET] setup RegCM3 for 360 day ICBC

[Maurice.McHugh at noaa.gov]

Hi everyone,

Just a quick point about line 261 in CCSM.f: when calculating the NREC (record number) variable - that should correspond to the record number for the date you want to create ICBCs for.    Please print out the time variable of your inputs - some software packages use weird conventions for representing monthly means in terms of "hours since 1900-00-00" or some other baseline.  I had record numbers like 70300.75 for monthly mean SST data.

I had some trouble with the time coordinates attached to the input data and spent a lot of time before I realized that the issue was not in the CCSM.f code, but in my input data.

Another thing to be aware of:  please create monthly mean SSTs for input to RegCM through SST_CCSM.f.  

Also, depending on whether you can get the CCSM ocean surface temperatures or have to use the radiative surface temperatures you will have to regrid the SSTs from a gaussian or POP grid respectively.  

NCAR's NCL package has useful functions for doing so, and also for regridding projected RegCM output to a lat/lon grid.

Hope this helps,

Maurice

----- Original Message -----
From: Moetasim Ashfaq <moetasim at stanford.edu>
Date: Sunday, March 28, 2010 11:47 pm
Subject: Re: [RegCNET] setup RegCM3 for 360 day ICBC
To: jagan TNAU <jagan at tnau.ac.in>
Cc: regcnet <regcnet at lists.ictp.it>


> Hi Jagan,
> 
> You should check regcnet archives for my email to Maurice on Feb 23,  
> 
> which includes working CCSM code as well as most of the information  
> needed to run the ICBC with CCSM data. In addition to the instructions 
>  
> in that email you should make following changes:
> 
> Line 261 in CCSM.f
> 1948 should be changed to the start year of time "units" in CCSM data. 
>  
> This can be checked by using ncdump on any of the ccsm netcdf files.
> Line 438 in SST_CCSM.f
> atime should be equal to the number of time steps in your SST data file.
> 
> Moet
> 
> 
> 
> On Mar 28, 2010, at 7:51 PM, jagan TNAU wrote:
> 
> > Dear Xunqiang Bi,
> >
> > I have CCSM data for Asian domain. Other than the changes you  
> > mentioned  whether data sets of CCSM need to be modified because I  
> 
> > believe CCSM uses Gaussian grid.
> >
> > Similarly in the case of HadCM3 the data sets are prepared to run  
> > under UK Met Office PRECIS regional model. Is there any modification 
>  
> > required in the data as it uses rotated lat-lon.
> >
> > Or other words in which DATTYP I have to set in domain.param.
> >
> > On Mon, Mar 29, 2010 at 1:18 AM, bixq <bixq at ictp.it> wrote:
> >
> > Step I, ICBC.f  (under RegCM/PreProc/ICBC)
> >
> >  in ICBC.f, find the SUBROUTINE INITDATE, set all 12 month to 30 days
> >
> > NDAY = 30
> >
> > Step II,  INITDATE.F (under RegCM/Main)
> >
> >  do the same as above.
> >
> > Step III, solar1.F (under RegCM/Main)
> >  find dayspy, change it to 360 exactly (from original 365.24), like
> >
> >  Change
> >      dayspy = 365.24
> >  To
> >      dayspy = 360.
> >
> > Step IV, tgrund.F, (under RegCM/Main), probably this code doesn't  
> > matter.
> >
> >  Change
> >      xnua = xnu/365.
> >
> >  to
> >      xnua = xnu/360.
> >
> > Step V, if you are GrADS user, if you like, you need change all the  
> 
> > subroutines related to writing out GrADS CTL files.
> >
> >
> > I guess that you are using HadCM3 output, right.
> >
> > For the user use CCSM data (CCSM use 365 days, no leap year), he/she
> > also have to do the similar modifications.
> >
> > Regards,
> > Xunqiang Bi
> >
> >
> > On Sat, 27 Mar 2010, u.utku.turuncoglu at be.itu.edu.tr wrote:
> >
> > Hi,
> >
> > I try to setup a RegCM3 run that uses HadCM output as an initial and
> > boundary condition. As you know, the year is defined as 360 day in  
> 
> > HadCM
> > model and i think that RegCM main code must be modified for this  
> > case. I
> > do following modifications,
> >
> > 1 - update dayspy value to 360. in solar1.F.
> >
> > 2 - comment or delete lines between 24 and 34. I also added  NDAY=30 
>  
> > after
> > these lines.
> >
> > I just want to ask that are these modifications correct? Do i need any
> > additional steps?
> >
> > Best regards,
> >
> > --ufuk
> >
> >
> > -- 
> > This message has been scanned for viruses and
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> >
> > _______________________________________________
> > RegCNET mailing list
> > RegCNET at lists.ictp.it
> > 
> >
> >
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >  Dr. Xunqiang Bi         email:bixq at ictp.it
> >  Earth System Physics Group
> >  The Abdus Salam ICTP
> >  Strada Costiera, 11
> >  P.O. BOX 586, 34100 Trieste, ITALY
> >  Tel: +39-040-2240302  Fax: +39-040-2240449
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > _______________________________________________
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> > 
> >
> >
> >
> > -- 
> > With regards
> >
> > Dr.R.Jagannathan	
> > Dean (Agriculture),
> > Tamil Nadu Agricultural University,
> > Vanavarayar Institute of Agriculture,
> > NIA Educational Institutions,
> > Pollachi - 642 003 India	
> >
> > PHONE:  Mob: +91 94438 89891
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> > 
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