Full vorticity equations

[rduran]

Hi,

I would like to track down any papers using/describing the full vorticity equations (2D and/or 3D) say from cross-differentiating ROMS diagnostics or any other method.

Does anyone know the details for such references?

thanks.

Rodrigo.

[Ryan_Holmes]

Hi Rodrigo,

I used the ROMS diagnostics for a Lagrangian budget of 3D vertical vorticity in section 3 of this reference: http://dx.doi.org/10.1175/JPO-D-13-0157.1

Also, a similar thing for the horizontal component of 3D vorticity is contained in section 4 of: http://dx.doi.org/10.1175/JPO-D-14-0209.1

Cheers,

Ryan

[patrickm]

Couvelard X., P. Marchesiello, L. Gourdeau, and J. Lefevre, 2008: barotropic zonal jets induced by islands in the southwest Pacific. Journal of Physical Oceanography, 38, 2185-2204.

[rduran]

Excellent, thank you very much Ryan, Patrick.

[stone]

Hi, all
Thanks for supplying references for vorticity budget diagnostics. I think lots of user would be very interested in it. But I am still not sure how can we calculate the terms practically as shown in Cartesian coordinate, considering In the ROMS model, the equations of motions are solved in a transformed coordinate system which has a generalized topography-following s coordinate in the vertical direction and orthogonal curvilinear (xi, eta) coordinates in the horizontal directions [Haidvogel et al., 2000]. I mean how to transform back, for vorticity equation, using ROMS diagnostic output?
I guess it is required to calculate vorticity budget terms on ROMS native grid on-line to close the budget, any off-line diagnosis based on interpolated (to Cartesian coordinate) model-state-variables would cause budget-closure failure. Is there any detailed references that guide me how to figure out this problem, better if with coding strategy? Or maybe I am totally wrong?

Thanks.

Stone LU

[jpringle]

I do not know if this helps, but attached is a calculation of relative and potential vorticity that exactly parallels the code in Vorticity.F, but implemented in python. It calculates both 3D and shallow water vorticity. Please look at the function defineVorticity() for the calculation. I have included in the comments the corresponding lines of FORTRAN code from the model.

Note, in understanding the code, pay attention to the comments on how the ROMS indexing in FORTRAN differs from the python indexing into the same arrays.

ALSO: this code was written for my purposes; you will need to read what I have done and adapt it to your model. defineVorticity() should be general. The calling code needs to be arranged for your model configuration. Your mileage may vary.

Jamie Pringle
University of New Hampshire