[MITgcm-support] Problem: Extreme Tidal Currents in the Simulation at Narrow Channels.

[Killampalli Rajesh]

Dear Martin

Thank you for your response. I repent for having missed it. My model domain
is the Coringa Estuary on India's east coast. where several creeks/channels
meet to the estuary is my model area. I'm making a high-resolution tide
model with a horizontal resolution of 100m for this domain. Include name
list and model code files. Please see links 1 and 2. In link 2 I followed
the method to preprocess the baroclinic tidal current where Data from
TPXO7.2 was utilized to produce boundary conditions (OBEam, OBEph)
amplitude and phase.

http://wwwcvs.mitgcm.org/viewvc/MITgcm/MITgcm_contrib/tides/?diff_format=s&sortby=log&pathrev=HEAD
https://github.com/RajeshKillampalli/MITgcm_tidesetup_02/tree/main

On Tue, May 14, 2024 at 7:02 PM Killampalli Rajesh <rajesh70530 at gmail.com>
wrote:

> Dear MITgcm community
>
> I have added additional points to the earlier post "Extreme tidal currents
> in the simulation at narrow channels".Model mesh resolution is 100 metres.
> I'm attempting to resolve this issue by adjusting the bottomdragliner
> coefficient, which was previously set to 0.002. When it increases to 0.006,
> the model blows up and writes NaNs. For 0.005, the model may run, but the
> velocities are not reduced as expected, and less variance is recognised.
> Currently, the maximum channel flow was 1.25m/s; after modifying to 0.005,
> it was 1.21m/s redused. and I experimented with ViscAh from 10 to 100, but
> no substantial difference was seen. Can someone advise how to solve this?
>
>
> Best Regards
> Killampalli Rajesh
>
> On Wed, May 8, 2024 at 6:56 PM Killampalli Rajesh <rajesh70530 at gmail.com>
> wrote:
>
>> Dear MITgcm community
>>
>> Thank you for your assistance; I'm modelling tidal circulation in the
>> lagoon, which is connected to the coastal seas.The research region includes
>> lagoon and coastal waterways. The boundary conditions include baroclinic
>> tidal currents at open boundaries in data.obcs, OBEam, and OBEph only on
>> the eastern border, and OBCS_Tides specified in the model. The model
>> results is verified using tidal heights with the tide gauge data, however
>> the tidal currents are exaggerated. In example, the model findings suggest
>> extremely strong tidal currents at the mouth/channel, which contradicts
>> reality.
>>
>> Best Regards
>> Killampalli Rajesh
>>
>>
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