Positive Vorticity Advection

[Gianni Messeri]

    Hi all,
    I want to calculate PVA and I use the following script:

                define vort = hcurl(u,v)

   2.
          |define dtx = cdiff(vort,x) |
          define dty = cdiff(vort,y)
          define dx = cdiff(lon,x)*3.1416/180
          define dy = cdiff(lat,y)*3.1416/180
          display -1*( (u*dtx)/(cos(lat*3.1416/180)*dx) + v*dty/dy )/6.37e6

I expected maximum values of PVA of 40-50 10e-9/Se2, but my values are
greater (up to 350).

Can anyone help me?

Thanks in advance

Gianni


--
Gianni Messeri
La.M.M.A (Laboratorio Meteorologia e Modellistica Ambientale)
CNR-IBIMET (National Research Council - Institute of BioMeteorology)
Edificio D - via Madonna del Piano - 50019 Sesto Fiorentino (FI) - Italia
Tel. +39 0554483033; Fax +39055444083
Web: www.lamma.rete.toscana.it
Web: www.ibimet.cnr.it
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