Ocean Modeling Discussion

Hello,
I have a quick question. Could anybody tell me what is the bottom boundary condition on temperature?
I use ana_btflux.h. How does ROMS is it? Is it btflux=Kv*dT/dz or btflux=Kn*dT/dn, where n is normal to the bottom boundary?

Thanks a lot,
Evgeny

Thanks John,

It helps a lot.

Hi All,

I am having some trouble with using term diagnostics in the equation for temperature. In particular vertical and horizontal advection terms looks pretty suspicious.
I did the estimates for the terms just "by hand"- using temperature and velocity fields. And the estimates for all the terms ...

Hey Jessica,
Glad to see you here!

As I understand you did this:
#define UV_LDRAG

Try this to get no slip:
RDRG == 5.0d-02

Works for my application.

All the best,
Evgeny

Hi All,

I am simulating stratified flow in the channel. I want to maintain a steady linear stratification (temperature).
To do so I use ana_btflux and ana_stflux.

In flat bottom case it worked well I just set them to some appropriate (the same for both) value, depending on the desirable intensity ...

Hi Kate,
Thanks for your reply.
I am using ana_vmix. And so far I keep constant value of AKt everywhere in the domain. T do that to keep theory simple. And it was good enough for the flat bottom domain.

Now I added sloping bottom to the problem. Due to the downwelling favorable wind advection of ...

Hi All,

I am looking at the case of downwelling favorable wind driven flow in the domain with the sloping bottom.

This leads to an advection of lighter fluid beneath heavier fluid.

Could anybody tell me if there are any special tools in ROMS to intensify mixing in regions of unstable ...

The problem was in using

#define SPLINES
#define UV_SADVECTION

I terned them off and now everything is working

The resolution is pretty hight already. It has 5-6 points in Ekman layer, so I don't think there should be a problem with resolution. I'll try the bigger values of Vertical mixing

Hi Alexander,

Thanks a lot for your reply!

Yep, Ekman layer is there, but as you said it is 4.5m. And indeed there is a significant correction on the field in the Ekman layer, which actually tends to go to the right value of du/dz (that would satisfy a stress condition).

But We see a very sharp ...

Hi all,

I have a question about surface boundary condition.

I run application with uniform wind in x-direction sustr=5e-8 and with a constant value of Akv=1e-3.

When I checked the output the stress condition (sustr=Akv*du/dz) didn't work! Value in the output (Akv*du/dz) is ~15% less.

What is ...

Hi all,

I have a question about the dia.nc file. What kind of terms does it contain?
Are those terms have simply form of the terms in N-S equations or something more complicated?

u_accel
u_hadv
u_vadv
u_cor
u_prsgrd
u_hvisc
u_vvisc

temp_rate
temp_hadv
temp_vadv
temp_hdiff

Could you tell me if ...

Thanks a lot John!

Hi all,

In my problem I use ANA_VMIX, where I define AKv and AKt to be equal to constant AKv_bak=1e-3 and AKt_bak=1e-3 respectively.

if defined EKMAN_WALL
DO k=1,N(ng)-1
DO j=JstrR,JendR
DO i=IstrR,IendR
Akv(i,j,k)=Akv_bak(ng)
END DO
END DO
END DO


if defined EKMAN_WALL
DO k=1,N(ng)-1
DO ...

Hi All,

Could somebody explain how the advection and diffusion of temperature calculated? TS_U3HADVECTION TS_C4VADVECTION?

I am trying to simulate a case in which vertical advection of temperature is balanced by horizontal diffusion of temperature. (with background linear stratification ...

Hello all,

Could you tell me is it possible to run ROMS for 2D applications? So consider the problem only in z(vertical) and y(horizontal) coordinates. I am trying to do that to avoid instabilities.

Thanks a lot,
Evgeny

Thanks a lot for the suggestions!

Now it does work when switched to
#define MIX_S_UV

Hi All,
I consider a simple case of wind driven flow in the channel (Wall and periodic BCs) with sloping bottom (cross the channel). So there should be no variation in the flow along the channel. But the output of the run demonstrate significant variations in the flow along the channel.

I believe ...

just a quick check - i assume you did a pcolor on the bottom bathy and the slope is in the right direction? how did you add the slope? is it a tiling issue in the way you may have set ana grid ??
(these are just a few quick guesses).

Thanks for your reply.
Yep I did pcolor and the slope is in a ...

Hello,

I am using ROMS for running very simple model.
Uniform wind stress on the top is from West to East direction. No stratification.

BCs:
Wall for North and South
Periodic for E-W

For flat bottom case I got good output (Ekman top and bottom flow, interior flow in the direction of the wind ...

Hello,
I have a question about the WALL boundary condition.

I consider 3D rectangular basin with uniform wind forcing on the top in E-W direction. I put periodic boundary conditions in E-W direction and WALL boundary conditions on the North and South.

So I put no slip condition GAMMA2 = -1.0d0 in ...

Hi,
I have a question about periodic boundary conditions.
In cppdefs.h I defined EW_PERIODIC. And I got that omega goes to 0 at the boundaries. And far from the boundaies it is non0. Could you explain what kind of boundary condition is EW_PERIODIC?

Thanks a lot,
Evgeny

Hi all,
I have a simple question. Can somebody tell me what kind of boundary condition is WALL (in cppdfs)? In particular what kind of bc it sets for a velocity parallel to the wall?

Thanks a lot,
Evgeny