[MITgcm-support] Re: OBCS sponge and prescribe code checked in
Martin Losch
mlosch at awi-bremerhaven.de
Wed Sep 22 02:28:56 EDT 2004
setting fldperiod=repeatperiod should work, i agree, but what if I
don't have a repeatperiod ...? Ok, I can always use a very long
repeatperiod, much longer than my integration, but that's not very
nice.
If you like, I can try to fix this in exf_getffieldsrec. Do you think
the proposed code is sufficient?
Martin
On Sep 21, 2004, at 10:23 PM, Patrick Heimbach wrote:
> Martin,
>
> can't you just set for the field that's constant
> fldperiod = repeatperiod
> that is, e.g. for lwdown
> lwdownperiod = whatever.your.repeat.period.is
> It should then always cycle through to record 1.
>
> That should work, shouldn't it.
> But maybe not totally intuitive, so maybe
> worth changing at some point.
>
> -Patrick
>
>
>
> Quoting Martin Losch <mlosch at awi-bremerhaven.de>:
>
>> Patrick,
>> still another question about EXF. I thought that I can specify
>> different forcing periods for different data. For example, I have
>> hourly time dependent short wave surface forcing, so I specify
>> swdownperiod = 3600.0, etc. but my long wave surface forcing is
>> constant in time, so I specify lwdownperiod = 0., but then the model
>> crashes while reading lwdownFile, actually before that because in
>> exf_getffieldsrec there is a division by zero=fldperiod=lwdownPeriod.
>>
>> I suggest the following fix (but haven't tested that at all so far):
>> CML)
>> if (fldperiod.eq.0 ) then
>> fac = 0.
>> count0 = 1
>> count1 = 1
>> changed = .false.
>> else
>> CML)
>> C this is the original code
>> if (repeatPeriod.eq.0.) then
>> elseif()then
>> else
>> endif
>> CML(
>> endif
>> CML)
>>
>> Or have I overlooked something?
>>
>> Martin
>>
>> On Sep 21, 2004, at 1:38 AM, Patrick Heimbach wrote:
>>
>>>
>>> Hi Martin, Uli, and others,
>>>
>>> I've just checked in code in pkg/obcs/ that
>>> * ALLOW_OBCS_PRESCRIBE allows prescibing time-dependent obcs values,
>>> * ALLOW_OBCS_SPONGE sponge layers
>>> * ALLOW_OBCS_BALANCE rudimentary balancing of normal barotropic flow
>>>
>>> tag is checkpoint55a_post
>>>
>>> The stuff I checked in at least doesn't break
>>> the existing verif.'s that use obcs ;o)
>>> The code has been / is used in a few open boundary setups,
>>> it compiles ok, but no guarantee that the merging may have
>>> broken some of the new stuff.
>>> Any feedback on bugs, improvements etc are welcome.
>>>
>>> One feature/caveat is that the time-dependent prescibe
>>> runs in conjunction with exf, cal., i.e.
>>> S/R OBCS_CALC calls S/R EXF_GETOBCS
>>> If someone wants to volunteer to call
>>> external_fields_load alternatively, please.
>>>
>>> The files read are
>>> xz files (northern, southern boundary)
>>> yz files (eastern, western boundary)
>>>
>>> I've put a few "template" CPP options and runtime parameter files
>>> under
>>> http://mitgcm.org/cgi-bin/viewcvs.cgi/MITgcm_contrib/heimbach/
>>> obcs_prescribe/
>>>
>>> A verif. experiment will hopefully come soon.
>>>
>>> -Patrick
>>>
>>>
>>>
>>> Quoting Patrick Heimbach <heimbach at MIT.EDU>:
>>>
>>>>
>>>> Hi Martin,
>>>>
>>>> there is code for sponge layers and code for reading
>>>> 2D (xz, yz) boundart slices (was part of ECCO).
>>>> I wanted to merge it with the main code last week,
>>>> but didn't have time since I also had to catch up
>>>> with the adjoint (-> c55).
>>>> Will try it in the first half of this week
>>>> (remind me ;o).
>>>>
>>>> -Patrick
>>>>
>>>> Quoting Martin Losch <mlosch at awi-bremerhaven.de>:
>>>>
>>>>> Hi,
>>>>> now the obcs-package has got me. In the global_ocean.90x40x15
>>>>> experiment, I would like to introduce open boundaries in the south
>>>>> and/or north to emulate polar regions. Now the simplest and
>>>>> dirtiest
>>>>> way to do it would be through restoring in external_forcing. But I
>>>>> want
>>>>> to do it the hard and clean way and use the obcs package (o: A few
>>>>> questions arise:
>>>>> 1) as a general rule/how-to I start by modifying obcs_calc, so that
>>>>> after calling obcs_calc, the boundary values at time myTime+deltaT
>>>>> are
>>>>> known. Why myTime+deltaT, why not the current time=myTime?
>>>>> 2) ALLOW_OBCS_SPONGE: Is there code for sponge layers, or am I
>>>>> completely responsible for it myself (subroutine
>>>>> obcs_sponge_u/v/t/s)?
>>>>> As far as I know, a sponge layer is not much more than a restoring
>>>>> zone, correct? If I use a sponge layer (#define ALLOW_OBCS_SPONGE),
>>>>> will I still have an open boundary? Or in other words: just having
>>>>> restoring in external_forcing.F is not the same as
>>>>> ALLOW_OBCS_SPONGE
>>>>> and do the restoring somewhere in obcs_sponge_u/v/t/s, etc? It
>>>>> seems
>>>>> so.
>>>>> 3) not quite OBCS, but related. I want to read my open boundary
>>>>> values
>>>>> from a file (in calc_obcs), so I have to create code for that, fair
>>>>> enough; but because I only want to read one xz-slice, for example,
>>>>> (there is even an MDSIOREADFIELDXZ, impressive), I have a problem
>>>>> with
>>>>> exchanging the xz-slice, or did I just not find the excange_xz_r?
>>>>> file?
>>>>> Does anyone have experience with this?
>>>>>
>>>>> Martin
>>>>>
>>>>> _______________________________________________
>>>>> MITgcm-support mailing list
>>>>> MITgcm-support at mitgcm.org
>>>>> http://dev.mitgcm.org/mailman/listinfo/mitgcm-support
>>>>>
>>>>
>>>>
>>>> --------------------------------------------------------
>>>> Patrick Heimbach Massachusetts Institute of Technology
>>>> FON: +1/617/253-5259 EAPS, Room 54-1518
>>>> FAX: +1/617/253-4464 77 Massachusetts Avenue
>>>> mailto:heimbach at mit.edu Cambridge MA 02139
>>>> http://www.mit.edu/~heimbach/ USA
>>>>
>>>> _______________________________________________
>>>> MITgcm-support mailing list
>>>> MITgcm-support at mitgcm.org
>>>> http://dev.mitgcm.org/mailman/listinfo/mitgcm-support
>>>>
>>>
>>>
>>> --------------------------------------------------------
>>> Patrick Heimbach Massachusetts Institute of Technology
>>> FON: +1/617/253-5259 EAPS, Room 54-1518
>>> FAX: +1/617/253-4464 77 Massachusetts Avenue
>>> mailto:heimbach at mit.edu Cambridge MA 02139
>>> http://www.mit.edu/~heimbach/ USA
>>>
>>
>>
>
>
> --------------------------------------------------------
> Patrick Heimbach Massachusetts Institute of Technology
> FON: +1/617/253-5259 EAPS, Room 54-1518
> FAX: +1/617/253-4464 77 Massachusetts Avenue
> mailto:heimbach at mit.edu Cambridge MA 02139
> http://www.mit.edu/~heimbach/ USA
>
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