About Rotated EOF patterns of NCEP reanalysis 500mb monthly data

Hi all,
I need help in performing the rotated EOF of NCEP/NCAR reanalysis data
using NCL. I used the code eof_4.ncl present on ncl functions page. This
code use the same data i.e. 500mb monthly data set from NCEP/NCAR from 20S
to 90S but this code only calculates the EOF. This code is originally
written for calculating AAO oscillations.
For my case, i change the region from 20-90 N and for rotated EOF, i added
these lines in the code

;;;;;;; Rotation of EOF

ev_rot = eofunc_varimax_Wrap(eof,1)
printVarSummary(ev_rot)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
ev_rot1 = eofunc_ts_Wrap (wx, ev_rot, optETS)
ev_rot1 = dim_standardize_n( ev_rot1, 0, 1)
; =================================================================
; Regress
; =================================================================
 ev_regres = ev_rot ; create an array w meta
data
  do ne=0,neof-1
     ev_regres(ne,:,:) = (/ regCoef(ev_rot1(ne,:),
xAnom(lat|:,lon|:,time|:)) /)
  end do
At the end, i plot this ev_regres which contains REOF1 and REOF2. According
to many papers and definitions of Climate prediction centre, the first REOF
should be NAO and second should be PNA. In my case, the first EOF is NAO
but it is slightly different. The second EOF is capturing PNA but it is not
exact. I am attaching the figure.
For my research i need PNA pattern which is second REOF. It is capturing
PNA but also some other variabilties too.
Thanks for the help in advance.

-- 
Best Regards
Waqar Younas
PhD Candidate
Natural Resources and Environmental Studies (NRES)
University of Northern British Columbia (UNBC)
Canada

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