[ncl-talk] Some confusion about functions pot_vort_isobaric and static_stability

[Gmail]

Dear Dennis,

 

In the function pot_vort_isobaric, the isenbaric PV is calculated as follows

 

  vr  = vr + conform(vr,f,nlt)     ; absolute vorticity

  s   = where(s.eq.0, s at _FillValue, s)    ; safety

  con = R/(s*conform(t,p,npr))

                                   ; G* added to get common pv units

  pv  = -G*(vr + con*(dvdp*dtdx-dudp*dtdy))*dthdp

 

where the static stability (s) is computed by the function static_stability

s = -T*d[log(theta)]/dp = -(T/theta)*d(theta)/dp

 

(1)If so, I think the variable con should be

               con = 1/s

(2) Or, the static stability (σ) is computed by the function by the following formula 

Holton, James R., and Gregory J. Hakim. An introduction to dynamic meteorology. Vol. 88. Academic press, 2012. pp496

                σ = -R*T0/p* dln ϴ/dp

     then,

                con =R/(s*p), just as con = R/(s*conform(t,p,npr))

 

Thank,

 

Andy

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20151217/6b9f6c91/attachment.html