Overturning vs Density

[nils rix <nrix@xxxxxxxxxxxxxxx>]

Here's a question that concerns a rather common oceanographic diagnostic 
but seems to be rather nonsimple to handle in ferret.
I would simply like to contour a meridional overturning streamfunction 
against density as the vertical coordinate. That implies binning the 
velocity data into density classes before then integrating the stream 
function for the correct density bins over x and z.
Has anybody done this kind of diagnostics in ferret?
I've tried something like:
use v_temp_salt.dat
let/title=density dens = rho_un(salt,temp,z)
define axis/t=1022:1052:1/unit="density" axdens
let r0 = dens[l=1] - t[g=gdens]
let rv = r0[z=@weq:0] * v[l=1]
let v_on_dens=rv[z=@sum]
let ovt=v_on_dens[x=@din,z=@iin]*dimfac
contour ovt

This doesn't do the trick though! The main problem is that the variable 
rv is so big, that I don't have enough memory to then do any calculation 
or plotting with it. Secondly I'm not so sure whether the afterwards performed 
integration does the right thing in terms of integrating velocity belonging 
to a specific density class over a density layer cross section defined on 
the x-z-grid though. Can anybody help and give me a solution or some clues?

Cheers Nils  


address:
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Nils H. Rix
Dept. Theor. Oceanogr.            phone: (nat.)     0-431-597-3986
Inst. f. Meereskunde                   : (int.)  ++49-431-597-3986
Duesternbrookerweg 20               fax:         ++49-431-565-876
24105 Kiel, FRG                   e-mail: nrix@ifm.uni-kiel.de 
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