source: trunk/northwind.pro @ 42

;
; NAME: northwind.pro
;
; PURPOSE: Check on in the intput field the level of coherence of winds nearby north pole,
;          and corrects it. Thi stask is performed before interpolation 
;
; CATEGORY: Subroutine
;
; CALLING SEQUENCE: northwind
;
; INPUTS: 
;
;
; KEYWORD PARAMETERS: None
;
; OUTPUTS: 
;          zresul : the same wind field with its upward stripe
;          corrected in order to get coherence of winds on north polte
;
; COMMON BLOCKS:
;          common_interp.pro
;
;
PRO northwind, datglo,zdata_name,t

@common_interp

; Treatment of north pole stripe 

    
; Get from global array, the last stripe and the last but one stripe
 
;    Initialising data arrays

     datglo_rect  = replicate(0.,2,jpiatm)
     datglo_rectb = replicate(0.,2,jpiatm) 

; Put data of the last two stripes into arrays

     
     datglo_rect(0,*) = datglo(*,jpjatm-1,0)
     datglo_rect(1,*) = datglo(*,jpjatm-1,1)

     datglo_rectb(0,*)= datglo(*,jpjatm-2,0)
     datglo_rectb(1,*)= datglo(*,jpjatm-2,1)

     

; Converts data of these two lines into polar coordinates

     add_angle=0.

     if (zdata_name EQ data_u_name) then add_angle=!PI/2


     datglo_polar=CV_COORD(FROM_RECT=datglo_rect,/TO_POLAR)
     datglo_polar(0,*)=datglo_polar(0,*)+2*!PI*indgen(jpiatm)/jpiatm

     datglo_polarb=CV_COORD(FROM_RECT=datglo_rect,/TO_POLAR)
     datglo_polarb(0,*)=datglo_polar(0,*)+2*!PI*indgen(jpiatm)/jpiatm
    

; Coherence of the last line needs to be corrected

     print, 'CHECKING LAST LINE COHERENCE...'

     mean_mod=replicate(total(datglo_polar(1,*))/jpiatm,jpiatm)
     mean_arg=replicate((total(datglo_polar(0,*))/jpiatm+2*!PI*west_lon/360.+!PI*(jpiatm-1.)/float(jpiatm)) ,jpiatm)
     mean_argb=replicate((total(datglo_polarb(0,*))/jpiatm+2*!PI*west_lon/360.+!PI*(jpiatm-1.)/float(jpiatm)) ,jpiatm)

     

     ; Checks whether module is about the same on the North Pole line :
    
     test_mod=abs(mean_mod-datglo_polar(1,*))

     IF ( max(test_mod)/mean_mod(0) ) GT 0.01 THEN BEGIN
    
          print, 'MODULE IS NOT COHERENT AND WILL BE CORRECTED TO A MEAN VALUE OF :', mean_mod(0) 
          
          datglo_polar(1,*)=mean_mod
         
     ENDIF
    

     ; Checks whether argument is coherent on the North Pole line :

     test_arg=abs(mean_arg-datglo_polar(0,*))

     IF ( max(test_arg)/mean_arg(0)) GT 0.01 THEN BEGIN 

          print, 'ARGUMENT IS NOT COHERENT AND WILL BE CORRECTED TO A MEAN VALUE :', mean_argb(0)
  
          datglo_polar(0,*)=mean_argb-!PI/2-(2*!PI*indgen(jpiatm)/float(jpiatm)+replicate(2.*!PI*west_lon/360.,jpiatm))
           
     

     ; Cross Corellation Method for wind coherence on North Pole

     all_phases=indgen(jpiatm)
     
     Ux=mean_mod*cos(all_phases*2.*!PI/jpiatm)
     Uy=mean_mod*sin(all_phases*2.*!PI/jpiatm) 

     phyx=C_CORRELATE(Ux,datglo(*,jpjatm-2,0),all_phases)

     phyy=C_CORRELATE(Uy,datglo(*,jpjatm-2,1),all_phases)


     deph_x=where(phyx EQ max(phyx))
     deph_y=where(phyy EQ max(phyy))
     
     deph_x=deph_x(0)
     deph_y=deph_y(0)

     


     Ux=shift(Ux,deph_x)
     Uy=shift(Uy,deph_y)

     datglo(*,jpjatm-1,0)=Ux
     datglo(*,jpjatm-1,1)=Uy
 

     ENDIF

 
    

end