Ocean Modeling Discussion

Hi all, I’m simulating a barocliniczlly unstable flow in an E-W periodic channel. I’d like to restore the zonal mean (in I-direction) density to a prescribed climatology. I have modified “step3d_t.F” to do zonal average in the following way, but I worry if the implementation is correct. I’d really ap ...

Hi Kate,
Thanks for your reply.
Yes, you are right. The j-index range is 41-75.

I tried your suggestion to release drifters every Fdt interval (= 0.0417 day).

tile of 6 x 8 works (as before)
tile of 6 x 12 works
But, tile of 12 x 8 still failed. The model ran for 2.5 day and hanged.

Hi all, I am new to the lagrangian float option in ROMS. My goal is to release line sources of drifters at different depth (top 8 vertical levels) and repeat the drifter release every hour for 0.5 day. The way I do this is kind of dumb (suggestion?): in floats.in, I specify POS = G, C, T, N, Ft0 ...

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Hi Ed, thanks for the suggestions. I am testing the convergence with idealized M2 tidal forcing. Will report back!

To rduran: The max water depth is around 2000m, and I tried 20, 30, and 40 layers. The max. stiffness ratio is 0.4 (a bit high). I understand the period needed to resolve different harmonics. I just thought that the same dominant wave modes for adjustment would be resolved in the cases with ...

thanks for the reply!
The spatial resolution is variable. The highly resolved canyon region is 200m x 200m. But the grid coarsens to 4km near the boundaries.

Maybe the spin-up period of 30days is not long enough. I will try spatial grid refinement as well.

Hi all, I am simulating a regional sea off Taiwan where tidal flows over a submarine canyon generates internal tides (~ 50m isotherm displacement). The canyon is about 10km wide and is around 300-400 meter deeper than its rim. The tidal forcing is from OSU TPXO, and the model-derived sea-level ...

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Thank John and Hernan for implementing the corrections. I have tested it out, and zeta + h at dry cells is < Dcrit now. Plus, total mass conserves very well.

Hi all, There may be a potential problem in the ROMS fill value (spval = 1.0E+37) for dry cells when wetting/drying is activated. In Nonlinear/wetdry.F, when the local water depth (zeta + h) < Dcrit, the cell is considered dry, and rmask_wet and rmask_full of that cell is set to zero. Then, say for ...

I forgot to mention that the patch of suspended sediment never reaches the open boundary within the first two days. John Warner has helped identify a potential bug in sed_settling.F He suggested: line 177 (or close to that number): qc(i,k)=t(i,j,k,nnew,indx)*Hz_inv(i,k) relace that line with ...

re-post the figure

Hi all, I set up a very simple case to test whether passive tracer is conserved in shallow waters. I used sediment as a tracer (only one size class) but set the setting velocity to zero. So it behaves like passive tracer. When I used the ROMS-default advection scheme, the total mass conserves very ...

Hernan, Thanks for the clarification. Since vertical flux is what no fully represented in the sediment diagnostics, I tried to avoid it for now. So, I depth-integrated each term and expected the following to balance : Integral (mud_01_rate) ~= Integral (mud_01_hadv) - d/dt (bed_thickness * 2650 * (1 ...

Hi all, I'm examining the budget of transport equation for sediments in a shallow idealized estuary. I have only one sediment class, and the domain of interest is constantly wet and dry due to tides. Strangely, with DIAGNOSTICS_TS turned on, the transport equation is not closed??? The salt and ...

A bug ?? in wrt_rst.F line 106 Original: #ifdef PERFECT_RESTART ! ! Write out time-stepping indices. ! # ifdef SOLVE3D ntmp(1)=1+MOD((iic(ng)-1)-ntstart(ng),2) CALL netcdf_put_ivar (ng, iNLM, RSTname(ng), 'nstp', & & ntmp, (/tRSTindx(ng)/), (/1/), & & ncid = ncRSTid(ng)) IF (exit_flag.ne.NoError ...

Hi Milena, Thanks. I did modify the files you mention :D My second question is how to separate d/dx (u x S) into u dS/dx + S du/dx in the code. If you add the advection terms, the Sdu/dx+Sdv/dy+Sdw/dz = 0. But I want to compare u dS/dx and v dS/dy in tracer transport equation. So I'm trying to ...

Hi all, In ROMS standard TS_DIAGNOSTICS output, the advection terms (x and y) are combined into one term (salt_hadv and temp_adv). I'm trying to separate them in step3d_t.F but am not sure: 1. whether my modifications (see below) are correct or not? Another related question is that the advection ...

Hi all, I'm using ANA_WWAVE to analytically specify wind-induced waves. In analytical.F or ana_wwave.h, an input of wave direction (Dwave) is needed. Assuming that the waves are propagating toward positive XI direction, should I use Dwave = 270 * deg2rad (following LAKE_SIGNELL test case)? Does it ...

I tried to restart and save model history field more frequently. Turn out it's the ANA_SEDIMENT that caused problems. But I have not figured out what I did wrong.
Thanks so much for the suggestion. I will try the USE_DEBUG option and post the result (hopefully soon).

Hi all, I recently experienced a strange problem after migrating to ROMS 3.0. My application worked fine for serial run but blew up for parallel run (tilting 1 x 4). After blowing up, one of the computing node died. Such strange behavior happened repeatedly. Suggestion is greatly appreciated ...

Hi nganju,
I encountered a similar post-compilation segmentation fault using OpenMp. Have you resolved that problem yet? If so, do you mind sharing the trick? Thanks

Shih-Nan

Liejun,
if the problem is stack size, setting "ulimit -s unlimited" on the command line may not work. Try putting it in your .bashrc to see if it solves the problem. ---- Shih-Nan

i had the similar issue but solved it by add "ulimit -s unlimited" in my
.bashrc. i guess some batch system on clusters may ignore stack limits on a remote process.

Hi John, Thanks for your reply. I'm actually using the test case you set up (ESTUARY_TEST). I applied the same OBC as yours but used constant depth. #define EAST_FSGRADIENT #define EAST_M2CLAMPED #define EAST_M3GRADIENT #define EAST_TCLAMPED #define WEST_FSCLAMPED #define WEST_M2REDUCED #define WEST ...

Hi all, I'm setting up tidal forcing (only M2) for an estuarine channel (20 m deep) and encountered some problems. I'll appreciate if somebody can kindly give me some hints: The first configuration is a channel with one open boundary. I used #define NORTHERN_WALL #define SOUTHERN_WALL #define ...

hi all, I'm a new user and trying to understand the UPWELLING test case first. In the UPWELLING case, Lm is 41 and Mm is 80. But in the output file the bathymetry (h) is 43x82. So, there is one extra point at the boundary (?). I know the depth proflie is set up in analytical.F as below ...