[ferret_users] Ocean vertical velocity calculation in z-coordinate

[yangxing zheng <yangxingz@xxxxxxxxx>]

Hi,

    Last time, I asked for help in calculating w in
the ocean assuming we have u, v at each level. I
remember some suggest use continuity equation.
However, I try this way, but error is large.

   I just simply do this way (assume rho's effect is
small)

   let conv = (u[x=@ddc] + v[y=@ddc])*(-1.0)
   let w = conv[z=@iin]

  Steve suggests impose boundary condition w = 0 at
the surface(z=0?).

  I test the soda data which provides w data.

set data soda_20x_mon.mc

let div = (-1)*(u[x=@ddc] + v[y=@ddc])
let ww = div[y=30s,z=@iin]

set region/x=85w/l=1
plot ww[z=0:300],w[y=30s,z=0:300]

The figure is attached. w is provided by SODA that is
calculated within the model. ww is of course the
vertical value using ferret.

 Does anyone have idea between the two? Any better
calculation is welcome.


Yangxing


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