[RegCNET] RegCM Ensemble run

[James Ciarlo`]

Is there a reason why you chose to perturb only humidity and not
temperature and or surface pressure for instance?


On 3 May 2013 17:31, James Ciarlo` <james.ciarlo at physics.org> wrote:

> That is actually very helpful. Thanks :)
>
>
> On 3 May 2013 16:16, Travis O'Brien <travis.obrien at gmail.com> wrote:
>
>> Hi James,
>>
>> The ensemble_run flag is one of the parameters that activates the
>> ensembling system. This is a relatively new feature that is described in
>> the latest version of the RegCM UserGuide<http://gforge.ictp.it/gf/download/docmanfileversion/54/973/UserGuide.pdf>,
>> Section 6.1.7.
>>
>> When the ensembling system is activated, one or more of the boundary
>> condition fields are perturbed by a small fraction each time they are read
>> in.  For example, the following settings would use the ensembling strategy
>> of O'Brien et al. (2011) <http://dx.doi.org/10.1007/s00382-010-0900-5>,
>> which is the main reference that describes the details of the ensembling
>> method:
>>
>> &globdatparam
>>
>> ensemble_run = .true.
>>
>> /
>>
>> &perturbparam
>>
>> lperturb_q = .true.
>>
>> perturb_frac_q = 0.001d0
>>
>> /
>>
>>
>> With these settings turned on, each time you run regcm, the output will
>> be slightly different.  So to create an ensemble of simulations, you might
>> run RegCM five times, and each time change the parameter dirout to output.1,
>> output.2, output.3, output.4, output.5, etc.
>>
>> I hope this helps, and please let me know if I can clarify anything.
>>
>> Kind Regards,
>> -Travis-
>>
>> --
>> Travis O'Brien
>> Lawrence Berkeley National Lab
>> http://esd.lbl.gov/about/staff/travisobrien/<http://esd.lbl.gov/about/staff/travisobrien/index.html>
>> (510) 495-8047
>>
>>
>>
>>
>>
>>
>> On Fri, May 3, 2013 at 2:51 AM, James Ciarlo` <james.ciarlo at physics.org>wrote:
>>
>>> Dear RegCNET,
>>>
>>> I am interested in running an ensemble expleriment with RegCM4. My
>>> intention was to choose different settings for the different simulations.
>>>
>>> I have noticed the setting: ensemble_run = .false.,  in the
>>> globdatparam. This obviously needs to be set to true, but since I have
>>> never done an ensemble run before with RegCM4 I was wondering if there was
>>> anything I needed to know.
>>>
>>> Regards,
>>> James
>>>
>>> _______________________________________________
>>> RegCNET mailing list
>>> RegCNET at lists.ictp.it
>>> https://lists.ictp.it/mailman/listinfo.cgi/regcnet
>>>
>>
>>
>
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