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pedrocol / MOM6_pge_tests

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Pressure gradient formulations #5

Open pedrocol opened 1 year ago

pedrocol commented 1 year ago

The idea is to evaluate potential problems with the existing pressure gradient formulation and propose ways of action

pedrocol commented 1 year ago

There might be a problem with the existing formulation if we want to use it in ALE coordinates.

Adcroft et al., 2008: 'In general, the Montgomery form will tend to manifest a pressure gradient error when compressibility or the choice of vertical coordinate leads to along surface variations of alpha.' Being alpha = 1/rho - 1/rho_0.

The Montgomery potential is used as a correction of the pressure gradient formulation. As we can see, if the vertical coordinate is not isopycnal, the density difference in the same layer will lead to a variation of the pressure gradient. Or at least this is my understanding at the moment.