Ocean Modeling Discussion

rongzr

I usually save the restart file frequently for a hind-cast run, e.g. every month, so that I could restart the model easily. This works well when AVERAGES_DETIDE was not defined. When it was defined, ROMS output some new variables to the tidal FORCING file. As I see, it only output the latest ...

rongzr

Hi,All,I'm running a ROMS case in the Yellow Sea, China, with tides switched on. I got abnormal high temperature along the coast in summer, and abnormal low temperature near the front. The attached figure is the surface temperature in August. It seems to me that the tidal front is too strong. How to ...

rongzr

It's horizontal sawtooth which is more apparent at surface but could be seen all the depth. Yes. I'm doing one-way nesting. Both of them are initialized with climatology at zero time. I will try initialized the nest model later than the large model so that the both the initial and boundary are ...

rongzr

The u,v,w velocity show some sawtooth like things well far from the boundary.

rongzr

I'm running a case in a relatively small domain (10kmX10km, 182X182X5).The boundary condition is from the model output of a larger domain, including (u,v,zeta,ubar,vbar,temp,salt).The model blows up after running 2 days. I tried the following things, but the model just blow up at the same model time ...

rongzr

Sorry. I have no time to solve this problem right now. I think it shoulb be something related to ROMS input bug.

rongzr

I output the variable in the get_cycle.F Tvarname=river Tval= 1.00000000000000 2.00000000000000 Tmin= 1.00000000000000 Tmax= 2.00000000000000 Seems it are reading the wrong variable. The Tmin and Tmax should be 1 and 360 respectively.

rongzr

the same error even I set the river_time from 0 to 359! Seems i have to change some other configurations when using the latest version. Any ideas??

rongzr

I set the river time from 1day:1day:360day.This is fine for last version.For the new version, should i set it from 0 to 359 or how to solve the problem?

rongzr

Hi All, I got the following IO error after i updating to the latest revision(321), the output is like this: Horizontal mixing scaled by grid size, GRDMAX = 1.78056264E+01 km NLM: GET_STATE - Read state initial conditions, t = 0 00:00:00 (File: ECSYS_Test_Ini_Jul.nc, Rec=0001, Index=1) - free-surface ...

rongzr

Thanks,Jacopo. It's clear to me now!
I mistook TNU2 to VISC2. I have edited it.

rongzr

Hi,Jacopo, Thanks. I got your point. In my case, I will never set the horizontal viscosity to zero. So I just set visc2_r outside the sponge layer to visc2(ng) or visc2_r( visc2(ng)/grdmax(ng)*grdscl(i,j) , when VISC_GRID is defined). In my understanding, if not define the sponge layer, the ...

rongzr

Thanks Jacopo. I’m still a little confused. In the same subroutine (ana_hmixoef.h), if define VISC_GRID, they set the horizontal viscosity according to the grid size: cff=visc2(ng)/grdmax(ng) DO j=JstrR,JendR DO i=IstrR,IendR visc2_r(i,j)=cff*grdscl(i,j) END DO END DO I suppose the variable visc2_r s ...

rongzr

You may want to check the 2D equation of ROMS. In the 2D case, adding atmos. pressure is simply add it to the pressure gradient term.

rongzr

In the ROMS code, they just give a simple example #ifdef SPONGE ! !----------------------------------------------------------------------- ! Increase horizontal mixing in the sponge areas. !----------------------------------------------------------------------- ! !! User modifiable section. Please ...

rongzr

Thanks. Xiaochun!
I didn't adjust the ubar,ubar. That might be the reason why the model underestimated the tidal level when define UV_TIDES because i cut the depth to 1000m. I will check that. That's really helpful.

rongzr

Hi, John, Thanks for your reply. That might be one reason. I will test it. The reason why i didn't define UV_TIDES is that it underestimated the tidal amplitude,while with SSH_TIDES and FSOBC_REDUCED together i could get the tidal level right! I don't quit understand why SSH_TIDES and UV_TIDES ...

rongzr

Same thins occurs for the linear case.
Any idea? Thanks!

rongzr

The bottom velocity near the open boundary looks reasonable compared to the uniform case. Values lie between -0.05m/s ~ 0.05m/s and goes to extremely large when blowing up.

I'm testing the linear bottom friction case.

rongzr

Hi, Kate, thanks for your reply.
I use the logarithmic bottom friction(UV_LOGDRAG) with Zob=1mm.
The question is that model runs smoothly with uniform TS field but blows up with initial stratification. Do you think it might due to some other reason, e.g. baroclinic instability or what else?

rongzr

I set up a tidal model with summer climatological TS field. The model run 20days and blow up. I checked the model output and found that the sea level very near the open boundary goes to extremely large in several time steps. I use the following tidal flag: #define SSH_TIDES #define RAMP_TIDES ...

rongzr

According to my experience, you need to edited this two files (1)mode_forces.F--------Define Pair and PairG so that ROMS can read it !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!edited by Zengrui Rong 06/02/2008 #ifndef SOLVE3D # if defined ATM_PRESS real(r8 ...

rongzr

Warner, thanks for your help. I test both of them
1) Has the USE_DEBUG on give no more error information.
2) It does work for the 10 vertical layers case!!
Any idea about that?

rongzr

It doesn't work even i undefine all the flags related to PSources. The same error occurs. I think the grid size maybe the issue! I test it with my old grid(240x180x20). It works fine! It seems MPDATA needs large memories/CPUS. Now the maximum CPU i can use is 12. How to solve this problem? Any ...

rongzr

I add a free surface Chapman boundary condition for the river source. I works fine for other advection schemes.

rongzr

TS_MPDATA works fine for UPWELLING! The following is my header file, are there any conflict?? /* Basic physics options */ #define UV_COR #define UV_ADV #define UV_VIS2 #define TS_DIF2 #define SOLVE3D #define SALINITY #define MIX_GEO_UV /* mixing on geopotential (constant Z) surfaces */ #define MIX ...

rongzr

The grid size is 362X242X20; I use 10 CPUS and the real boundary conditions(tide). Does MPDATA need large memories?? The following are the relative parameters: Lm == 240 ! Number of I-direction INTERIOR RHO-points Mm == 360 ! Number of J-direction INTERIOR RHO-points N == 20 ! Number of vertical ...

rongzr

When I define TS_MPDATA, the model can be compiled successfully. But the following error occurs when running it: STEP Day HH:MM:SS KINETIC_ENRG POTEN_ENRG TOTAL_ENRG NET_VOLUME 0 0 00:00:00 0.000000E+00 3.897334E+03 3.897334E+03 5.162515E+14 DEF_HIS - creating history file: high_keps_0001.nc WRT_HIS ...

rongzr

You are right! The TPXO velocity at the boundary is too small compared to the model output (don't know whether due to my fault or the TPXO data yet, checking). It seems that the Flather boundary tends to transform potential energy to kinematic energy, right? I use SSH_Tides & FSOBC_REDUCED, it works ...

rongzr

I don’t know whether it’s due to the progressive loss of amplitude, since the model value at the boundary is also about 20 percent smaller than the given value (TPXO). Also the model value reduced to the smaller value very quickly (half M2 cycle) before it reaching the coast. So I think it may not du ...

rongzr

yes, I have specified them.
I use SSH_TIDES and UV_TIDES, and given the tide amplitude, tide phase, tide current ellipse, inclination at the open boundary.

rongzr

Kate,thank you for your reply.
I rerun it with VISC2(horizontal viscostiy) setting to zero. There seems no difference with the former run.
Why the model reduce the amplitude immediatly at the bounday?

rongzr

We are trying to use ROMS to predict tides in the East China Sea. The model-predicted phase compares well with the observation. But the amplitude is smaller then the observation by about 10-20 cm over the whole domain, especially along the coast. We further checked the model-predicted value (output ...

rongzr

I’m going to simulate the Changjiang river plume. I got a problem about the tracer concentration. When i define the ‘TS_U3HADVECTION’, the salinity goes to negative. Somebody told me that i should define ‘TS_MPDATA’ instead, there are no negative values then, but the model blows up after about 30 mod ...

rongzr

I note that the OA package is published aroud 2003, and ROMS has changed form old version to new version. I wonder are the variables defined in OA still available for the new ROMS? Should I make some changes to the output variable names?

Ocean Modeling Discussion

Search found 35 matches

How to restart when define AVERAGES_DETIDE?

Abnoraml high/low temperature along the coast?

Re: model blowing up at exact the same model time!!!why??

Re: model blowing up at exact the same model time!!!why??

model blowing up at exact the same model time!!!why??

Re: problems after updating to latest revision(321)

Re: problems after updating to latest revision(321)

Re: problems after updating to latest revision(321)

Re: problems after updating to latest revision(321)

problems after updating to latest revision(321)

Re: how to set the spong layer

Re: how to set the spong layer

Re: how to set the spong layer

Re: apply the atmosphere pressure in Storm simulation

how to set the spong layer

Re: tidal model blow up with initial stratification

Re: tidal model blow up with initial stratification

Re: tidal model blow up with initial stratification

Re: tidal model blow up with initial stratification

Re: tidal model blow up with initial stratification

tidal model blow up with initial stratification

Re: apply the atmosphere pressure in Storm simulation

MPI error when define TS_MPDATA???

why does model underestimate the tidal amplitude???

Blow up/define TS_MPDATA

OA package for ROMS3.0