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Hello
Good morning

How is a simulation of ocean currents?
I need your help

Gio

Hello,

Could you please state your question a bit more precisely. Do you want to prescribe a tide at the limits of your model ? Otherwise generally speaking ocean currents, if you filter tidal currents, are difficult to reproduce because they are due to causes which act on very large domains, not to say on the whole planet, like very little average free surface slopes due to differential evaporation and continents acting as obstacles, Coriolis force, etc. Programs that simulate ocean currents at large scales use a lot of data assimilation.

With best regards,

Jean-Michel Hervouet

Thank you very much for your response
Sir Jean-Michel Hervouet.

I have the simulation TPOX
I need currents to simulate outfall

As I can continue?
Thank you very much for your reply

Hello,

I do not really understand what you mean. If you have boundary conditions given by a TPXO database, it will hopefully give you the tidal currents as well...

Regards,

JMH

Sir Jean-Michel Hervouet
Thank you very much for your reply

For the outfall is enough tidal currents? or I need an ocean current.

Where I live they say currents from south to north but
the results of the simulation is the current going south - north - north - south...

Cordially

Gio

Hello,

OK, so I understand more. You mean residual currents that would not be due to tides but to a general circulation which cannot be reproduced in a local model. Actually I do not know, the databases should give a "constant in time but variable in space" value that would trigger this general circulation but I am not sure that they do this (think that, without friction and at European latitudes, a slope of 1 cm per km gives a geostrophic current of about 1 m/s). This is a question that I ask myself also (answers from users welcome). I'll discuss this with colleagues (when they are back...). Anyway it should be possible to add a small linear in space elevation at the boundaries of a domain to get such a residual current, though it would require some tuning. The values given by databeses may be tuned also, multiplied by a correction factor, if I understand well, but I do not really catch how a residual current can pop up from this, since it is quite another phenomenon.

With best regards,

Jean-Michel Hervouet

Hello
In my model set up am getting tidal forcing only once and for the remaining time step the current velocity is becoming almost zero
Pls help me with this

I like to know whether the bathymetry values should be positive or negative in the geometry file

Hello,

The bathymetry is positive or negative depending on your reference, the point is that it is growing when you go up, so directed upwards.
If you still have problems I'll ask a specialist to give you an answer on the tidal boundaries.

With best regards,

Jean-Michel Hervouet

Sir,
I still have problem in the tidal current simulation. I am clear with the bathymetry now but if you see the simulation in my case there is only one force is visible inflowing after that there is no next tide. Pls help me in this regard. My doubt is if semidiurnal or diurnal there must be forcing per every particular time interval but which is not occuring in my case. only the residual currents are seen. It will be helpful if I have good example problem or step by step input procedure for the tide current simulation.

Thank you