How to calculate vertical velocity of barotropic tide

General scientific issues regarding ROMS

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stone

How to calculate vertical velocity of barotropic tide

#1 Unread post by stone »

Hi,all
I am trying to use ROMS to simulate internal tide.
I need to calculate the rate of conversion from barotropic to baroclinic energy, which uses vertical velocity of barotropic tide.
I think it should be differrent from the formula in usual sigma coordinate as POM does.How to calculate this velocity, any one give me some advice please?
Thanks .

staalstrom
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Joined: Mon Feb 04, 2008 3:43 pm
Location: NIVA, OSLO, NORWAY

Re: How to calculate vertical velocity of barotropic tide

#2 Unread post by staalstrom »

Hi

I think this is very interesting. I look at internal waves in a sill fjord. ROMS seems to create internal waves without any parametrization. The problem is to describe the sill without introducing to much pressure gradient errors because of the steep topography.

What does the usual conversion formula for sigma coordinates (used in POM) look like?
I guess isopycnal vertical coordinates should be the most suitable coordinates? So generalized vertical coordinates should work just as good as sigma-coordinates.

Staalstrom

stone

Re: How to calculate vertical velocity of barotropic tide

#3 Unread post by stone »

What does the usual conversion formula for sigma coordinates (used in POM) look like?
Image
where U is barotropic veloclity, D is water depth, sigma is the sigma coordinate,eta is free surface.
see attatched file for details.
I now use barotropic tide velocity(depth average) to calculate omega and w component due to this horizontal velocity along the s-isosurface using RNT toolbox. It seems good.
Please let me know if I misused the RNT rnt_wvelocity.m function.
Attachments
JanSen Numerical study of baroclinic tides in Luzon Strait .pdf
(3.23 MiB) Downloaded 414 times

stone

question about non-hydrostatic

#4 Unread post by stone »

Hi,all
I have a simple question . Can our ROMS catch the internal wave?
Non-hydrostatic is important in this phenominion,isn't it.
I find some information about non-hydrostatic in wiki-ROMS
https://www.myroms.org/wiki/index.php/N ... _Technique
Image
Does this mean Rutgers ROMS can simulate internal wave? Has ROMS coded the non-hydrostatic part yet?

Thanks.

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kate
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Location: CFOS/UAF, USA

Re: How to calculate vertical velocity of barotropic tide

#5 Unread post by kate »

My incomplete understanding is that you should get internal tides if you resolve the horizontal scales of just a kilometer or two. I'd ask an internal tides expert - maybe I'll see one at lunch time.

No, the Rutgers ROMS does not have the non-hydrostatic part. I'm not sure you strictly need it.

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