[Go-essp-tech] RIP clarification

[Karl Taylor]

Yes,  that is what is called for in the DRS document.  Thanks for 
reminding us.

Karl

On 2/2/11 12:51 AM, Stéphane Senesi wrote:
> 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-mailcharlotte.pascoe at stfc.ac.uk <mailto:c.l.pascoe at rl.ac.uk>
>>>
>>> ----------------------------------------------------------
>>>
>>>
>>> -- 
>>> Scanned by iCritical.
>>>
>>>
>>
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>>    
>
>
> -- 
> 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)
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