passive temperature and salinity

[asujrpv]

Hello everybody,

I have been able to run ROMS for a small area, with stratification in Temperature and Salt.

I would like to do the same but without stratification at all, just for comparison. My question is what flags should I use in my cdw.h file?

in the *.in file, what should I write for active/innactive tracers?

NAT = 0 ! Number of active tracers (usually, 2)
NPT = 1 ! Number of inactive passive tracers
NCS = 0 ! Number of cohesive (mud) sediment tracers
NNS = 0 ! Number of non-cohesive (sand) sediment tracers



Here is what I think should be, but please let correct me. As I said, I would like to run my case without scalars (for comparison).

/*
** svn $Id: basin.h 547 2011-04-13 21:32:58Z arango $
*******************************************************************************
** Copyright (c) 2002-2011 The ROMS/TOMS Group **
** Licensed under a MIT/X style license **
** See License_ROMS.txt **
*******************************************************************************
**
** Options for Big Bad Basin.
**
** Application flag: CDW
** Input script: ocean_cdw.in
*/
/*
** Options for cdw example
*/
/* Model physics */
#define SOLVE3D
/* #define SALINITY */
#define T_PASSIVE
#define UV_ADV
#define DJ_GRADPS
#define UV_COR
#define UV_QDRAG
#define NONLIN_EOS
#define SPLINES
#define GLS_MIXING /* use if Generic Length-Scale mixing */
#define N2S2_HORAVG
#define KANTHA_CLAYSON
#define MIX_S_UV /* use if mixing along constant S-surfaces */
#define MIX_S_TS /* use if mixing along constant S-surfaces */
#define RAMP_TIDES
/*
#define MASKING
*/


#define SSH_TIDES
#define UV_TIDES

#define NORTH_FSCHAPMAN
#define NORTH_M2FLATHER
#define SOUTH_FSCHAPMAN
#define SOUTH_M2FLATHER
#define EAST_FSCHAPMAN
#define EAST_M2FLATHER
#define WEST_FSCHAPMAN
#define WEST_M2FLATHER

#define ANA_INITIAL
#define ANA_FSOBC
#define ANA_M2OBC
#define ANA_SMFLUX
#define ANA_STFLUX
#define ANA_SSFLUX
#define ANA_SRFLUX
#define ANA_BSFLUX
#define ANA_BTFLUX


/* Lateral boundary conditions*/
/* #define EAST_FSRADIATION /* use if free-surface radiation condition */
#define EAST_M3RADIATION /* use if 3D momentum radiation condition */
#define EAST_KRADIATION /* use if TKE fields radiation condition */
#define EAST_TRADIATION /* use if tracers radiation condition */
/* #define WEST_FSRADIATION /* use if free-surface radiation condition */
#define WEST_M3RADIATION /* use if 3D momentum radiation condition */
#define WEST_KRADIATION /* use if TKE fields radiation condition */
#define WEST_TRADIATION /* use if tracers radiation condition */
/* #define NORTH_FSRADIATION /* use if free-surface radiation condition */
#define NORTH_M3RADIATION /* use if 3D momentum radiation condition */
#define NORTH_KRADIATION /* use if TKE fields radiation condition */
#define NORTH_TRADIATION /* use if tracers radiation condition */
/* #define SOUTH_FSRADIATION /* use if free-surface radiation condition */
#define SOUTH_M3RADIATION /* use if 3D momentum radiation condition */
#define SOUTH_KRADIATION /* use if TKE fields radiation condition */
#define SOUTH_TRADIATION /* use if tracers radiation condition */
~
~

[kate]

My guess, not being in the office, is that the setup you propose will not work. ROMS will be expecting two active tracers with the use of the nonlinear equation of state. I think you need to have at least one active tracer and you should use a linear equation of state, with coefficients provided in the ocean.in file. Likewise, GLS_MIXING is going to be looking at your tracer, density, etc. fields so you might want to switch to a more predictable vertical viscosity. You will also need tracer boundary conditions of some sort or the other - just be aware that not setting any will provide a wall boundary condition.

Beyond that, try some things and see what happens.

[arango]

If you want a run without stratification just set temperature and salinity to be spatially uniform. For example, temp(i,j,k)=25 and salt(i,j,k)=35. You need to use the linear equation of state with perhaps SCOEF=0 (temperature is a proxy for density). You also need to have zero surface and bottom vertical fluxes for temperature and salinity. This is equivalent to have a shallow-water set-up but with vertical levels.

Perhaps, what you just need is just to solve the vertically integrated ROMS equations (SOLVE3D is undefined).

[asujrpv]

Many thanks, this worked the way you mentioned.

thanks!
Rafael