about the usage of background brunt vasaila frequency

[leonjld]

hi, I have a case in which I want to change the stratification. will it make any difference if I change the BVF_BAK in the input file? will that value has any effect in the momentum equation? it seems from the code that BVF_BAK is only used in brunt-vasaila frequency dependent vertical mixing? just want to make sure.

[arango]

No, this parameter is only used to scale the energy norm in adjoint-based algorithms for singular vectors and optimal perturbations. If you want to change the stratification in any ocean modeling application, you need to change the vertical gradients of density. That is, you need to change your initial conditions for temperature and salinity. There is not other way. You cannot control change easily of stratification via a vertical mixing parametrization because it involves nonlinear processes between ambient circulation and external forcing.

[Kun]

No, this parameter is only used to scale the energy norm in adjoint-based algorithms for singular vectors and optimal perturbations. If you want to change the stratification in any ocean modeling application, you need to change the vertical gradients of density. That is, you need to change your initial conditions for temperature and salinity. There is not other way. You cannot control change easily of stratification via a vertical mixing parametrization because it involves nonlinear processes between ambient circulation and external forcing.

If I use the ROMS ADJOINT MODEL to do some work. Here is one problem: If I want use the energy norm for all kinds of perturbations, I know kinetic energy (involved with du dv) and gravitational potential energy (involved with dzeta). But how can deal with the dtemp and dsalt varibles in the energy norm in ROMS??