Search found 24 matches

by patrickm
Sat Jun 02, 2018 5:33 am
Forum: ROMS Discussion
Topic: Nonbreaking wave-induced mixing in ROMS?
Replies: 7
Views: 1646

Re: Nonbreaking wave-induced mixing in ROMS?

Hi Kate, note that nonbreaking-wave-induced mixing and Langmuir turbulence are generally considered two different processes of wave-induced mixing (related to Stokes drift)... Patrick
by patrickm
Fri Jun 01, 2018 5:54 am
Forum: ROMS Discussion
Topic: Nonbreaking wave-induced mixing in ROMS?
Replies: 7
Views: 1646

Re: Nonbreaking wave-induced mixing in ROMS?

For wave‐induced vertical mixing in KPP, see Wang et al., JGR 2010, based on Qiao et al, JPO 2004. It is now part of CROCO (ROMS_AGRIF)
by patrickm
Thu Oct 08, 2015 8:08 am
Forum: ROMS Results
Topic: The problem about creating an idealized warm ocean eddy
Replies: 5
Views: 2707

Re: The problem about creating an idealized warm ocean eddy

a square vortex is possible, but you need some resonant vortex Rossby waves. See this plot by Schubert et al. (1999). I also heard that G. Roullet (LPO, France) has presented some results at the Ocean Sciences meeting where he could make a square vortex using some flux-corrected advection schemes ...
by patrickm
Thu Oct 01, 2015 5:34 am
Forum: ROMS Problems
Topic: CPU time and MPI issues with nested grids
Replies: 16
Views: 5437

Re: CPU time and MPI issues with nested grids

just a precision. ROMS_AGRIF also uses a full stencil at the interface (nesting with 1:1 gives the same results as no nesting at all). The model runs stably with 1:5 ratio, which gives excellent results in 2-way nesting (1:3 is preferable for 1-way nesting, because the solutions are naturally less s...
by patrickm
Wed Sep 23, 2015 5:48 am
Forum: ROMS Discussion
Topic: Error encountered in compiling jobcomp using Romstools
Replies: 8
Views: 2339

Re: Error encountered in compiling jobcomp using Romstools

Hi, please use the ROMS-AGRIF forum for your problem ... Patrick
by patrickm
Sun May 17, 2015 10:15 am
Forum: ROMS Discussion
Topic: Simulation of Standing Waves Using ROMS
Replies: 5
Views: 1838

Re: Simulation of Standing Waves Using ROMS

yes Kate, we have done the TANK test case in the homogeneous and two-layered fluid (internal soliton) using a non-hydrostatic version of ROMS_AGRIF. We can accurately reproduce both the hydrostatic and non-hydrostatic analytical solutions in the homogeneous case and lab experiments in the two-layer ...
by patrickm
Tue Mar 31, 2015 5:59 am
Forum: ROMS Discussion
Topic: Full vorticity equations
Replies: 5
Views: 2584

Re: Full vorticity equations

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.
by patrickm
Tue Oct 14, 2014 5:27 am
Forum: ROMS Bugs
Topic: WET_DRY and Dcrit
Replies: 13
Views: 6851

Re: WET_DRY and Dcrit

The implicit correction of Lemarié et al. (2012) fixes the problem for us (in ROMS_AGRIF). We implemented it for both interior diffusion (bi-laplacian) and sponges (laplacian) and WET_DRY runs without any problem in all configurations (e.g., with wetting-drying cells in sponge areas).
by patrickm
Tue Oct 01, 2013 7:13 am
Forum: ROMS Bugs
Topic: Possible Bugs in Radiation OBC in t3dbc_im.F
Replies: 2
Views: 1945

Re: Possible Bugs in Radiation OBC in t3dbc_im.F

Hi Hernan, could that explain the "inconsistency" between surface bulk formulations and OBCs in the simulations that you presented in Rio last year?
by patrickm
Mon Jun 24, 2013 7:35 am
Forum: ROMS Discussion
Topic: Marchesiello's RSUP3 in ROMS?
Replies: 9
Views: 1987

Re: Marchesiello's RSUP3 in ROMS?

Since the response is slow to come, I will give my understanding of the status of RSUP3. The RSUP3 scheme presented in Marchesiello et al. (2009) was first implemented in the ROMS_AGRIF version and we had some success with it on various applications. Then, a form of it was implemented in the Rutgers...
by patrickm
Mon Jun 04, 2012 6:35 am
Forum: ROMS Discussion
Topic: A simple question about default obc in old version roms
Replies: 9
Views: 3867

Re: A simple question about default obc in old version roms

I think that this discussion demonstrates the fact that users should not have to choose their combination of OBCs (unless they really want to). in the ROMS_AGRIF version, there is a default set of choices which avoids a lot of trouble for users and a much faster start up. concerning 2D radiative con...
by patrickm
Wed Jan 25, 2012 7:29 am
Forum: ROMS Bugs
Topic: is LMD constancy preserving
Replies: 9
Views: 3381

Re: is LMD constancy preserving

Hi Sasha, Thanks for the details on the radiative heating choices. I understand the issue of Bflux changing sign with depth and how it may affect the physical consistency of nonlocal mixing. This is a good point that leaves us with interesting physical issues. Note that we are well aware of the "bug...
by patrickm
Tue Jan 24, 2012 5:13 pm
Forum: ROMS Bugs
Topic: is LMD constancy preserving
Replies: 9
Views: 3381

Re: is LMD constancy preserving

Hi Sasha, In your formulation you use : NonLocalFlux = C * G(sigma) * SurfaceForcingFlux taking: SurfaceForcingFlux = stflx(i,j,itemp) - srflx(i,j) But in Large et al. (1994) SurfaceForcingFlux also contains the radiative heat absorbed in the boundary layer (at level sigma) as it was believed to con...
by patrickm
Sat Dec 17, 2011 12:05 pm
Forum: ROMS Tools and Techniques
Topic: TPXO to ROMS EXPRESS (tide extraction software)
Replies: 40
Views: 21511

Re: TPXO to ROMS EXPRESS (tide extraction software)

Hi John, make_tides now reads TPXO7 but we will look at your routines. The management and corrections of tidal phase and amplitude needed in the case of real time forcing is not straightforward. If you simplified some of the treatment processes, that would be interesting to us as well. We may want t...
by patrickm
Fri Dec 16, 2011 9:46 am
Forum: ROMS Tools and Techniques
Topic: TPXO to ROMS EXPRESS (tide extraction software)
Replies: 40
Views: 21511

Re: TPXO to ROMS EXPRESS (tide extraction software)

For information, the romstools package (provided with the agrif version of roms) also has a tidal toolbox (in matlab) that processes TPXO for ROMS. It is called make_tides ...
by patrickm
Wed Nov 09, 2011 9:14 am
Forum: ROMS Problems
Topic: sponge layer for biharmonic viscosity
Replies: 4
Views: 2565

Re: sponge layer for biharmonic viscosity

Did you try and reduce the hyperviscosity coefficient? the rotation of biharmonic tensor induces large vertical fluxes that violate stability constraints (see Marchesiello et al. 2009). Clipping of hyperviscosity is needed in this case ...
by patrickm
Wed Oct 12, 2011 3:53 pm
Forum: ROMS Discussion
Topic: advection and spurious mixing
Replies: 16
Views: 5424

Re: advection and spurious mixing

the circulation is not that affected by local extrema (unless out of control) but is greatly affected by diapycnal mixing.

a discussion on the need for monotonicity is good of course ...
by patrickm
Wed Oct 12, 2011 3:09 pm
Forum: ROMS Discussion
Topic: advection and spurious mixing
Replies: 16
Views: 5424

Re: advection and spurious mixing

monotonocity is far from being the only issue with tracer advection. An example of lock exchange experiment in different models is given by Flavien Gouillon (PhD thesis) at http://coaps.fsu.edu/~gouillon/Spurious.html again, monotone schemes have implicit diffusion, which becomes a problem with stee...
by patrickm
Wed Oct 12, 2011 2:08 pm
Forum: ROMS Discussion
Topic: advection and spurious mixing
Replies: 16
Views: 5424

Re: advection and spurious mixing

The scheme in Marchesiello et al (2009), let's call it RSUP3, is not meant to outperform UP3 (the standard ROMS upstream-biased advection scheme) in terms of numerical properties (accuracy, dispersion ...). It is only an attempt to correct excess diapycnal mixing that arises with steep slopes (even ...
by patrickm
Tue Oct 11, 2011 4:28 pm
Forum: ROMS Discussion
Topic: advection and spurious mixing
Replies: 16
Views: 5424

Re: advection and spurious mixing

I did not have much success with the Akima advection scheme. I think that the only progress from the scheme proposed in Marchesiello et al. (2009) is coming from Lemarié et al. (a paper that will soon be published). It is a significant update from my work that will allow isopycnal mixing (with no ad...
by patrickm
Fri Aug 22, 2008 1:18 am
Forum: ROMS Discussion
Topic: Operating ROMS nowcast/forecast models
Replies: 3
Views: 1400

Re: Operating ROMS nowcast/forecast models

We have also recently proposed a nowcast/forecast system over New Caledonia: http://prevision.ird.nc/ (look at PREVISIONS/OCEAN). It is based on a protable package developped as part of the Romstools (IRD team). Our New Caledonia system is presented in the July 2008 MERCATOR Newsletter n°30: http://...
by patrickm
Fri Jul 06, 2007 4:36 am
Forum: Job Opportunities
Topic: Hydrodynamic and cosystem modeler, IRD New Caledonia
Replies: 0
Views: 1266

Hydrodynamic and cosystem modeler, IRD New Caledonia

A 1-year postdoctoral position in regional modeling is available in the oceanographic lab of the IRD center of New Caledonia. The funding project is an integrated study of the relation between ecological conditions and tuna fisheries with a focus on regional ENSO and climate impacts. The person sele...
by patrickm
Fri May 11, 2007 2:50 am
Forum: ROMS Discussion
Topic: diapycnal mixing in 3rd order "horizontal" advecti
Replies: 0
Views: 949

diapycnal mixing in 3rd order "horizontal" advecti

Hi, I would like to report a problem with ROMS 3rd order "horizontal" advection scheme for tracer advection. This scheme is a very nice compromise between quality (no dispersion, quasi-monotonic) and CPU cost (see Shchepetkin, 1998). However, when applied to sigma coordinate models the issue of the ...