question about calculation of shflux ...

[turuncu]

Hi,

I have a question about calculation of shflux (or stflx) to provide surface net heat flux into the ROMS ocean model (no bulk option activated). Does it include the solar radiation component? or it is just a non-solar heat flux. Then, what is the actual formula to calculate shflux? Is it necessary to multiplied with -1?

Thanks,

--ufuk

[kate]

The convention is that a positive stflx(:,:,itemp) is a heating of the ocean surface.

Checking globaldefs.h, one can see the cases which require a separate srflx field:

Code: Select all

#if defined LMD_SKPP     || defined SOLAR_SOURCE   || \
    defined BULK_FLUXES  || defined BIOLOGY
# define SHORTWAVE
#endif

[arango]

The total net surface heat flux shflux input forcing variable (stflux(:,:,itemp) in ROMS equations) is ALWAYS the sum of four terms: shortwave radiation flux, longwave radiation flux, latent heat flux, and sensible heat flux. Its sign can be both positive (downward flux, heating) or negative (upward flux, cooling) The net heat flux is a vertical boundary condition to the temperature diffusion equation.

Now, in some applications we would like also to penetrate the shortwave radiation flux to a particular depth using a simple decay model that depends on the Jerlov water type or any other sophisticated approach that includes biological/sediment activity. This is usually used in vertical mixing parameterizations to compute surface and sub-surface radiative buoyancy flux. Notice that we are careful to not apply twice the shortwave radiation flux at the surface in the vertical diffusion of temperature. This is part of the physics of the oceanic surface boundary layer that we would like to model. If you have doubts about this, I will recommend to check the literature. This is described extensively in books and papers.