Search found 35 matches
- Tue Apr 29, 2014 8:31 pm
- Forum: ROMS Discussion
- Topic: Instabilities with SWAN_COUPLING and WET_DRY together
- Replies: 8
- Views: 9030
Re: Instabilities with SWAN_COUPLING and WET_DRY together
Here is what I did to reduce the size of the SWAN coupling/output files to keep them smaller than 2 Gigabytes: 1. Increase the coupling interval from 1 to 6 minutes. I can't remember exactly where I changed this run parameter. 2. The block output from SWAN has to be changed, too. That command in eri...
- Wed Nov 20, 2013 8:18 pm
- Forum: ROMS Problems
- Topic: Sea cliffs
- Replies: 8
- Views: 12406
Re: Sea cliffs
I just encountered the same problem again, this time on the volcanic island of Nakanoshima at lat-lon coordinates (29.875° North, 129.875° East). Nakanoshima is between Japan and Taiwan, and the summit of Mt. Ontake rises to 979 meters above sea level. With a grid resolution of 4 km, the grid has a ...
- Thu Apr 25, 2013 3:19 pm
- Forum: ROMS Problems
- Topic: ROMS blows up
- Replies: 6
- Views: 5810
Re: ROMS blows up
You never want to have any of your h values be zero. Period. h is the bathymetry at rho-points (positive downward). For my model domain the Shuttle Radar Topography Mission at 3 arc-seconds reports an elevation of 0 meters at several portions of the shoreline. Am I supposed to increase those values...
- Tue Mar 12, 2013 3:13 pm
- Forum: ROMS Discussion
- Topic: Wind AND tidal forcing in the Inlet test
- Replies: 2
- Views: 2863
Re: Wind AND tidal forcing in the Inlet test
Since storm surge and wind setdown develop over many hours, I took John's suggestion and made the lowering of the water level at the upwind/northern boundary dependent on time: #if defined INLET_TEST IF (NORTHERN_EDGE) THEN cff=-1.0_r8*sin(2.0_r8*pi*time(ng)/(12.0_r8*3600.0_r8)) cff = cff - 0.10_r8 ...
- Fri Mar 08, 2013 8:34 pm
- Forum: ROMS Discussion
- Topic: Wind AND tidal forcing in the Inlet test
- Replies: 2
- Views: 2863
Wind AND tidal forcing in the Inlet test
How would you modify the Inlet test to add onshore wind forcing? The Inlet test uses the northern domain boundary to generate tidal oscillations that propagate south through a narrow strait and into an inlet. Here is the tidal forcing in ana_fsobc.h within the Coupled sub-directory: #if defined INLE...
- Wed Jan 16, 2013 2:52 pm
- Forum: ROMS Discussion
- Topic: What to correct to keep ROMS from blowing up?
- Replies: 23
- Views: 25592
Re: What to correct to keep ROMS from blowing up?
I just debugged a blowup situation involving very shallow water and drying on the coast. From the color scale I cannot tell if your bathymetry rises above sea level, but if it does: Try increasing the critical depth DCRIT. This is a simple revision to make, and it might tell you something about the ...
- Fri Dec 14, 2012 4:10 pm
- Forum: ROMS Discussion
- Topic: River locations when there is wetting/drying
- Replies: 4
- Views: 5737
Re: River locations when there is wetting/drying
I'm working in the Nile delta, which is really flat. I have strong winds but no tide, and consequently there is a lot of wetting and drying going on. I have set my permanent land-sea mask at a height of 30 meters above sea level (absurdly high). I have a river point source at 5 meters above sea leve...
- Fri Oct 21, 2011 9:07 pm
- Forum: ROMS Discussion
- Topic: Dependence of water levels on sigma parameters
- Replies: 6
- Views: 5331
Re: Dependence of water levels on sigma parameters
Cd=RDRG2=0.003 is the ROMS default. Can you tell me what RDRG2=0.010 means physically? A lot of rocks on the bottom? A lot of seaweed? What would be a reasonable maximum value?I am using the ROMS Quadratic bottom friction formulation (UV_QDRAG) and have tried Cd=0.003-0.010 (constant) values.
- Wed Aug 03, 2011 4:53 pm
- Forum: ROMS Sediment
- Topic: ROMS-SWAN Coupled System Users
- Replies: 21
- Views: 27170
Re: ROMS-SWAN Coupled System Users
I am using ROMS-SWAN to study storm surge and wind setdown on Lake Erie. Wave radiation stress does not appear to make much difference. Is there a formulation for wave-dependent surface drag?
- Mon Jul 25, 2011 7:13 pm
- Forum: ROMS Discussion
- Topic: Instabilities with SWAN_COUPLING and WET_DRY together
- Replies: 8
- Views: 9030
Re: Instabilities with SWAN_COUPLING and WET_DRY together
I tried running the Lake Erie model with DCRIT = 0.5 meters and time step DT = 0.5 seconds. The maximum Courant value Cw reported in the ROMS log file is 0.939, which removes the possibility of a CFL violation. The model terminated at 01:53:56 hours with a blowup error in cell (399,192). That cell h...
- Wed Jul 13, 2011 6:05 pm
- Forum: ROMS Discussion
- Topic: Instabilities with SWAN_COUPLING and WET_DRY together
- Replies: 8
- Views: 9030
Re: Instabilities with SWAN_COUPLING and WET_DRY together
Converting SWAN to use the Nautical convention for wind was not easy. I am forcing SWAN from a file of wind components (all constant for now). The wind is blowing from the West-Southwest along the axis of the lake (20 degrees north of due east), from Toledo to Buffalo. This wind direction at 20 m/s ...
- Fri Jul 08, 2011 9:16 pm
- Forum: ROMS Discussion
- Topic: Instabilities with SWAN_COUPLING and WET_DRY together
- Replies: 8
- Views: 9030
Re: Instabilities with SWAN_COUPLING and WET_DRY together
It looks like my combined model has a direction problem. I had set up SWAN for Cartesian coordinates, but ROMS requires the Nautical convention for wave direction, as John pointed out in this recent thread: https://www.myroms.org/forum/viewtopic.php?f=14&t=2301 For SWAN use: SET INRHOG 1 NAUTICA...
- Wed Jul 06, 2011 10:02 pm
- Forum: ROMS Discussion
- Topic: Instabilities with SWAN_COUPLING and WET_DRY together
- Replies: 8
- Views: 9030
Instabilities with SWAN_COUPLING and WET_DRY together
I am applying wind stress at 20 m/s to Lake Erie at an angle of 20° north of due east (from the WSW, aligned with the axis of the lake). I get a blowup error at time 01:34:45 (hours), and upon further investigation I see unrealistic instabilities arising along the north shore, where the waves impact...
- Tue May 17, 2011 10:11 pm
- Forum: ROMS Problems
- Topic: problem when coupling roms and swan
- Replies: 1
- Views: 3064
Re: problem when coupling roms and swan
I was getting the same error messages shown in red above. The problem went away (and Inlet Test ran correctly) when I switched from /usr/local/mpich2-1.3.1-pgf90/bin/mpirun to /usr/pgi/linux86/8.0/mpi/mpich/bin/mpirun I suspect the problem came from a mismatch between the compilers used for building...
- Fri Apr 23, 2010 2:40 pm
- Forum: ROMS Discussion
- Topic: ROMS wetting/drying inundation/storm-surge simulations
- Replies: 2
- Views: 3628
Re: ROMS wetting/drying inundation/storm-surge simulations
MHHW is Mean Higher High Water: http://tidesandcurrents.noaa.gov/mhhw.html I use ROMS to study storm surge (wetting) and wind setdown (drying) in Egypt's Nile delta. I #define WET_DRY like John says, and use the default critical depth of 0.10 meters. I set my land/sea masking to 30 meters above sea ...
- Fri Feb 05, 2010 4:44 pm
- Forum: ROMS Bugs
- Topic: Incorrect nesting of OpenMP directives
- Replies: 4
- Views: 5055
Re: Incorrect nesting of OpenMP directives
More information: My model domain has one analytical point source of river inflow. ana_psource.h has three !$OMP BARRRIER directives in it (svn $Id: ana_psource.h 429 2009-12-20 17:30:26Z). One of those directives makes it into Build/analytical.f90, near line 174, just before the Qbar values are se...
- Wed Feb 03, 2010 9:42 pm
- Forum: ROMS Bugs
- Topic: Incorrect nesting of OpenMP directives
- Replies: 4
- Views: 5055
Re: Incorrect nesting of OpenMP directives
I believe that I am using shared memory alone and not distributed memory. Here is the entire USE_ section of build.bash: #export USE_MPI=on #export USE_MPIF90=on export FORT=xlf export USE_OpenMP=on #export USE_DEBUG=on export USE_LARGE=on #export USE_NETCDF4=on I am not using any customized makefil...
- Wed Feb 03, 2010 6:27 pm
- Forum: ROMS Bugs
- Topic: Incorrect nesting of OpenMP directives
- Replies: 4
- Views: 5055
Incorrect nesting of OpenMP directives
I get the following run-time errors on NCAR's bluefire supercomputer: 1587-114 Incorrect nesting of OpenMP directives. 1587-114 Incorrect nesting of OpenMP directives. SVN Revision: 442M. ROMS/TOMS version 3.4. The last entry in the ROMS log file is: Initial basin volumes: TotVolume = 5.0360477799E+...
- Tue Feb 02, 2010 8:21 pm
- Forum: ROMS Problems
- Topic: Velocities in land grid cells
- Replies: 15
- Views: 7698
Re: Velocities in land grid cells
Here is a picture of the staggered grid from the ROMS wiki:
https://www.myroms.org/wiki/index.php/Grid_Generation
(I guess my initial 16 m/s current is _not_ "reasonable", but at least it doesn't blowup!
)
https://www.myroms.org/wiki/index.php/Grid_Generation
(I guess my initial 16 m/s current is _not_ "reasonable", but at least it doesn't blowup!
![Laughing :lol:](./images/smilies/icon_lol.gif)
- Tue Feb 02, 2010 8:13 pm
- Forum: ROMS Problems
- Topic: Velocities in land grid cells
- Replies: 15
- Views: 7698
Re: Velocities in land grid cells
Here is the ubar current in my upstream grid cell (no masking): http://acd.ucar.edu/~drews/inflow.jpg Those points are at 1-second intervals. This appears to be the same numerical problem, judging from your plot. If you can get your 4 masks to accurately represent the ROMS concept of "upstream ...
- Mon Feb 01, 2010 4:36 pm
- Forum: ROMS Problems
- Topic: Velocities in land grid cells
- Replies: 15
- Views: 7698
Re: Velocities in land grid cells
I had a problem similar to this one a few weeks ago with SVN revision 436. I got extreme velocities in the cell directly upstream of my river point source. Some differences: 1. I am using the 2-D barotropic mode (1 vertical level). 2. My grid resolution is 86m, 10x finer than yours. 3. I have wetdry...
- Wed Nov 25, 2009 3:15 pm
- Forum: ROMS Discussion
- Topic: model blow-up due to abnormal temperatures
- Replies: 5
- Views: 5770
Re: model blow-up due to abnormal temperatures
This problem sounds like one I had last year: Water temperature from -492 to 602 degrees Celsius? https://www.myroms.org/forum/viewtopic.php?f=17&t=995 As Kate noted, the model involves 3D flow in shallow water. My fix was to #define MY25_MIXING in myModel.h, which turns on Mellor-Yamada vertica...
- Thu Nov 05, 2009 3:49 pm
- Forum: ROMS Problems
- Topic: Coupled ROMS-SWAN experiment
- Replies: 10
- Views: 7295
Re: Coupled ROMS-SWAN experiment
I have seen spuriously large currents along a domain boundary when the Coriolis force pushes the current against the wall. My solution was to set the domain boundaries to no-slip: GAMMA2 == -1.0d0 This change makes the walls less greasy. I am modeling wave radiation stress with NEARSHORE_MELLOR as y...
- Wed Aug 26, 2009 4:57 pm
- Forum: ROMS Installation
- Topic: what's the error?
- Replies: 4
- Views: 5783
Re: what's the error?
This error message: 0: ALLOCATE: 16721214976 bytes requested; not enough memory probably means that the ROMS executable has run out of memory, based on the grid size that you are using. 16 Gigabytes is a lot of space; I found a similar problem on my Linux workstation, when ROMS could not allocate ab...
- Fri Mar 13, 2009 3:21 pm
- Forum: ROMS Discussion
- Topic: Coupling ROMS and WRF
- Replies: 3
- Views: 6802
Re: Coupling ROMS and WRF
I just finished setting up a one-way forcing from WRF to ROMS (my Master's thesis project). I moved a 12-km grid of hurricane Katrina 2005 to the Philippines and sent it over Manila to see what storm surge would result. It works. The ROMS developers have set up a very nice scheme for time interpolat...
- Mon Feb 02, 2009 4:02 pm
- Forum: ROMS Discussion
- Topic: apply the atmosphere pressure in Storm simulation
- Replies: 10
- Views: 10141
Re: apply the atmosphere pressure in Storm simulation
I'm using the 2-D ROMS configuration to model typhoon-driven storm surge. My model is forced with winds and atmospheric pressure. The code edits provided by rongzr produce a 1.5-meter rise in sea level for 850 mb, which is what I expect (after some sloshing). Thanks! Here are the headers for my NetC...
- Mon Oct 27, 2008 2:16 am
- Forum: ROMS Problems
- Topic: Sea cliffs
- Replies: 8
- Views: 12406
Sea cliffs
What is the proper way for handling sea cliffs? In the Philippines, at about 121.283 degrees East and 13.6 degrees North, there is a sea cliff that rises from the deep ocean. At 900-meter horizontal resolution (SRTM30 data) the north-south cross section of bathymetry/topography is plotted below. The...
- Mon Oct 13, 2008 4:11 pm
- Forum: ROMS Problems
- Topic: storm surge problem
- Replies: 1
- Views: 2556
Re: storm surge problem
wjlee - The September 2008 issue of Physics Today had an article by Donald Resio and Joannes Westerink, "Modeling the physics of storm surges", that may be useful. On page 34 they state formula (1): height of surge eta is proportional to: (tau/gh)W This formula indicates that wind-driven s...
- Mon Aug 04, 2008 7:09 pm
- Forum: ROMS Problems
- Topic: Water temperature from -492 to 602 degrees Celsius?
- Replies: 2
- Views: 2779
Re: Water temperature from -492 to 602 degrees Celsius?
Kate - Thanks for the suggestions. (Sorry, I was looking at your Joined date, not the Bristol Bay Posted date.) I'm using a horizontal resolution of 100 meters, with a strong wind stress of 2.73 N/m2 blowing toward shore. Steep gradients in the bathymetry (1:20) blow up sooner than shallow gradients...
- Thu Jul 31, 2008 10:58 pm
- Forum: ROMS Problems
- Topic: Water temperature from -492 to 602 degrees Celsius?
- Replies: 2
- Views: 2779
Water temperature from -492 to 602 degrees Celsius?
I'm modeling wind stress toward a sloping shoreline. I get a blowup error at the same time and place that the water temperature spikes to hundreds of degrees Celsius, negative and positive. This problem sounds somewhat like the "Trouble in shallow water" discussion of Bristol Bay back in 2...
- Thu May 29, 2008 10:16 pm
- Forum: ROMS Discussion
- Topic: Test problem for wetting-drying
- Replies: 1
- Views: 2717
- Wed May 21, 2008 11:25 pm
- Forum: ROMS Problems
- Topic: Test cases
- Replies: 5
- Views: 4302
- Mon May 19, 2008 11:17 pm
- Forum: ROMS Problems
- Topic: Test cases
- Replies: 5
- Views: 4302
- Mon May 19, 2008 3:21 pm
- Forum: ROMS Discussion
- Topic: Left side of the upwelling example
- Replies: 3
- Views: 4486
That Python code
Jamie - Thanks for the information about mixing and convection. Your comments will be useful to me, since my research involves shallow water. That Python code is a quick-and-dirty script that I put together to produce a plot. I posted it in case someone needs to review my processing to answer my que...
- Thu May 15, 2008 11:12 pm
- Forum: ROMS Discussion
- Topic: Left side of the upwelling example
- Replies: 3
- Views: 4486
Left side of the upwelling example
I have plotted the flow vectors in a cross section of the upwelling example. Everything looks fine except for the left (south) side of the channel. Recall that the wind here is into the page and the Coriolis force is to the left (southern hemisphere). Here is the entire section: https://www.myroms.o...