How to obtain pressure or pressure gradient in ROMS

[jc_Sun]

Dear users,
Maybe I'm asking a stupid question, but I still can't figure out a good way to determine it after reading some posts. This is because I am asking to solve the kinetic energy budget equation, but the pressure or pressure gradient in the equation is not known to me. So what I am asking is whether the pressure or pressure gradient is included in the output of ROMS? If I define DIAGNOSTICS_TS and DIAGNOSTICS_UV in the head file and it does have the variable pressure gradient, but that's a time average value, how do I achieve that if I want to get the instantaneous value? Do I have to find the pressure P by P=ρgh+ρv^2/2 or density-Jacobian method? I'm looking forward to your answers！

[rduran]

pressure gradient:

• the averaged value tends to the instantaneous value as the averaging period tends to zero, six-hourly averages may not be much different than the instantaneous value you need.

• you can hack the code to not average

pressure:

• you can compute the pressure by integrating density (computed from T,S) with SSH as a boundary condition, there are routines for this out there

[jc_Sun]

pressure gradient:

• the averaged value tends to the instantaneous value as the averaging period tends to zero, six-hourly averages may not be much different than the instantaneous value you need.

• you can hack the code to not average

pressure:

• you can compute the pressure by integrating density (computed from T,S) with SSH as a boundary condition, there are routines for this out there

Dear rduran
Thank you very much for your answer!