# Re: bottom velocity vectors in a z-coordinate model

```Hi Both,

Arne's solution is clever!

Here's another variation on the theme -- a bit clumsier but more straight
forward -- shown by example using the temperature field of
levitus_climatology:

-----
use levitus_climatology
let k_index = k + 0*temp   ! the K index masked by "temp"
shade k_index[k=@max]   ! K index of the bottom cell
PAUSE
let k_mask = IF K[g=temp] EQ k_index[k=@max] THEN 1
let kernel = temp * k_mask
shade kernel[k=@sum]   ! temperature of the bottom cell
-----

ciao - steve

=================================

Arne Biastoch wrote:

> Johann,
>
> a simple quick and dirty way to calculate the deepest point of a
> variable vel this would be:
>
> let dummy=missing(vel,999999)
> let velbottmp=vel*dummy[z=@weq:100]
> let velbot=velbottmp[z=@sum]
>
> The problem is that the "weq" has to be close enough to the bottom value
> (at least larger). But with very high numbers for the missing value this
> becomes less and less sensitive.
>
> Hope that helps.
>
> Arne Biastoch
> following suggestions by Rolf Kaese
>
> Johann Jungclaus wrote:
> >
> > Hi,
> >  I am looking for a simple way to plot the velocity of the respective
> >  gridbox next to the bottom (something like the bottom velocity)
> >  Has anybody solved this problem already?
> > Many thanks
> > Johann
> > --
> > Dr. Johann H. Jungclaus
> > Max- Planck- Insitut fuer Meteorologie
> > Bundesstrasse 55
> > 20146 Hamburg
> > Germany
> > Tel +49 40 41173 109
> > Fax +49 40 41173 298
> > email jungclaus@dkrz.de
>
> --
>
> Dr. Arne Biastoch
> Scripps Institution of Oceanography        phone: +1-858-822-3787
> Physical Oceanography Research Division    fax  : +1-858-534-9820
> MS: 0230                                   email: abiastoch@ucsd.edu
> 8605 La Jolla Shores Dr.
> La Jolla, CA 92093-0230, U.S.A.   http://www.ecco.ucsd.edu/~biastoch

--

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```

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