[Go-essp-tech] RIP clarification

[Stéphane Senesi]

Dear all

Isn'it required, in addition, that r<N> values are consistent between an 
Historical run and each RCP run started form its 2006 state ?

S

Karl Taylor wrote, On 01/02/2011 19:57:
> Hi Charlotte,
>
> Congratulations! you managed to crack the intended use of "rip" in 
> spite of what I thought was  a scheme so complicated, that no mere 
> mortal could be expected to decipher it.
>
> That being said, I think we should probably expect others (with lesser 
> proclivity to meticulousness) to fail in attempting to follow the 
> recommendations.  In particular, we may not be able to count on the 
> "p" and "i" values being consistent across all simulations by a single 
> model.   If that were the case, would it completely disrupt your plans?
>
> One approach would be as follows:
> The first time that someone records the information for an experiment 
> (i.e., the first member of the "rip" ensemble), they would be asked to 
> document the model and all the experimental conditions.  Then when 
> subsequent members were entered, they should only have to reference 
> the first member and say how the model physics (in some cases when p 
> differs) or the experiment conditions (initial conditions when "i" 
> differs and in some cases "forcing" when "p" differs).  In the case of 
> a different value of "r", typically the "spawning" point from the run 
> will differ from one member of the ensemble to another.  [Note, 
> however, that for the TAMIP project, this identifies a different start 
> time for the forecast within the season.]
>
> Sorry it's so difficult.
>
> Best regards,
> Karl
>
> On 2/1/11 6:09 AM, charlotte.pascoe at stfc.ac.uk wrote:
>>
>> Hi Karl and Bryan,
>>
>> It is important to know how the r<N>i<M>p<L> indices are to be 
>> implemented in CMIP5 so that we can be sure that information about 
>> them is captured correctly by the questionnaire. Here is my 
>> understanding, please correct me if I’m wrong!
>>
>> The scope of the p<L> and i<M> indices are model wide – these indices 
>> must mean the same thing across all simulations for a particular model.
>>
>> The scope of the r<N> indices are experiment wide – the r index is 
>> not required to mean the same thing across all simulations for a 
>> particular model, so the r indices can be reused by different 
>> experiments.
>>
>> Here is an example to show what this would mean in practice.
>>
>> If the meaning of the r<N> indices were confined to an experiment
>>
>> then if you had used r1, r2, and r3 to label the members of an amip 
>> ensemble:
>>
>> tas_day_HADCM3_amip_r1i1p1_197901-200901.nc
>>
>> tas_day_HADCM3_amip_r2i1p1_197901-200901.nc
>>
>> tas_day_HADCM3_amip_r3i1p1_197901-200901.nc
>>
>> you could use r1,r2 and r3 again to label the members of a different 
>> experiment, say decadal2000:
>>
>> tas_day_HADCM3_decadal2000_r1i2p1_200001-201001.nc
>>
>> tas_day_HADCM3_decadal2000_r2i2p1_200001-201001.nc
>>
>> tas_day_HADCM3_decadal2000_r3i2p1_200001-201001.nc
>>
>> rather than having to begin labelling from a new r index, say r4:
>>
>> tas_day_HADCM3_decadal2000_r4i2p1_200001-201001.nc
>>
>> Where
>>
>> p<L> - identify perturbations in physics (from the same base model)
>>
>> i<M> - identify perturbations in initialisation method
>>
>> r<N> - identify ensemble members which differ in other characteristics.
>>
>> Please shout if my interpretation is wrong!
>>
>> Kind regards,
>>
>> *Charlotte*
>>
>> ----------------------------------------------------------
>>
>> Dr Charlotte Pascoe
>>
>> NCAS British Atmospheric Data Centre
>>
>> STFC Rutherford Appleton Laboratory
>>
>> Phone +44 1235 445869; Fax ...5848
>>
>> e-mail charlotte.pascoe at stfc.ac.uk <mailto:c.l.pascoe at rl.ac.uk>
>>
>> ----------------------------------------------------------
>>
>>
>> -- 
>> Scanned by iCritical.
>>
>>
>
> _______________________________________________
> GO-ESSP-TECH mailing list
> GO-ESSP-TECH at ucar.edu
> http://mailman.ucar.edu/mailman/listinfo/go-essp-tech
>    


-- 
Stéphane Sénési
Ingénieur - équipe Assemblage du Système Terre
Centre National de Recherches Météorologiques
Groupe de Météorologie à Grande Echelle et Climat

CNRM/GMGEC/ASTER
42 Av Coriolis
F-31057 Toulouse Cedex 1

+33.5.61.07.99.31 (Fax :....9610)

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/go-essp-tech/attachments/20110202/f3e0d97b/attachment-0001.html