PRO readqnblendwind



; IDL program to read binary blended wind data files.

; This routine can be adapted to read either the zonal and

; meridional wind data ("uv") or the windstress curl data ("curl").

;

; UV or Curl

;

;   Either read two arrays (u and v, in m/s), or one array (curl,

;   in N/m3).  

;

; Big-endian vs. little-endian

;

;   The data files were produced on a little-endian machine (pentium PC).

;   If reading from a big-endian machine, use the IDL keyword

;   "SWAP_IF_BIG_ENDIAN" in open statement.

;

; Geographic Grid

;   The data domain is a 0.5x0.5 degree grid, 720 x 353, starting at 

;   (0.5E, 88.0S) and ending at (360.0E, 88.0N).  There are data

;   values at all grid points, including land and ice points. 

;   Users who wish to examine ocean points only need to use 

;   appropriate land/ice masks.

;

; Time convention

;

;   Time is 6-hourly; the "day" variable is in days of year: 

;   e.g. January 1, 6hr = day 0.25. There is no February 29 in leap

;   years.  This data was produced for ocean models that require

;   a constant number of days per year.  In all years days go from 

;   0.25 to 365.00.

;

; Data file types

;

;   bln : QSCAT scatterometer data blended with NCEP analyses.

;         The blended data has realistic highwavenumber variability

;         everywhere and preserves the satellite data where it occurs.

;         For each 6-hourly field, 12 hours of QSCAT satellite swaths

;         are overlayed on the global NCEP analysis map, centered on the 

;         analysis time.

;

;   low : NCEP analysis splined to the 0.5x0.5 degree grid.

;

;

; Version 2.0, June     11, 2002

; Version 3.0, February 26, 2003: the sample output is from version 2.0 

;                                 blended winds

; Version 3.1, May 1      , 2003: for blended winds version 3.0,

;                                 the sample output is now in separate

;                                 file

;

;-----------------------------------------------------------------------



; data type



  readuv = 0  ; if readuv=1, read uv data, else read curl data



; parameters



  nlon = 720

  nlat = 353



  u = fltarr(nlon,nlat)

  v = fltarr(nlon,nlat)

  c = fltarr(nlon,nlat) ; for curl



; open input file



  if (readuv eq 1) then begin

     dfname =   'uv.200012.bln'

     dfname =   '/data/ocean04/data1/WINDqscat-1.v03/uv.200012.bln'

  endif else begin

     dfname = 'curl.200012.bln' 

     dfname = '/data/ocean04/data1/WINDqscat-1.v03/curl.200012.bln' 

  endelse



  print,'input= ',dfname

  get_lun,iunit

  openr,iunit,dfname,/F77_UNFORMATTED,/SWAP_IF_BIG_ENDIAN



; read data



  nread = long(0)



  g11: if(eof(iunit)) then goto, g99



  readu,iunit,day

  if (readuv eq 1) then begin

     readu,iunit,u

     readu,iunit,v

  endif else begin

     readu,iunit,c  

  endelse

  nread = nread + 1



  if (readuv eq 1) then begin ; print some u and v data

     uvformat='(/,"day=",f9.4," print data at i=",i4," to",i4,", j=",i4,/,"  u=",5e16.7,/,"  v=",5e16.7)'

     ip1 =  20

     ip2 =  24

     jp  =  19

     print,day,ip1+1,ip2+1,jp+1,u(ip1:ip2,jp),v(ip1:ip2,jp),format=uvformat

     jp  = 329

     print,day,ip1+1,ip2+1,jp+1,u(ip1:ip2,jp),v(ip1:ip2,jp),format=uvformat

  endif



  if (readuv ne 1) then begin ; print some curl data

     cformat='(/,"day=",f9.4," print data at i=",i4," to",i4,", j=",i4,/,"  c=",5e16.7)'

     ip1 =  20

     ip2 =  24

     jp  =  19

     print,day,ip1+1,ip2+1,jp+1,c(ip1:ip2,jp),format=cformat

     jp  = 329

     print,day,ip1+1,ip2+1,jp+1,c(ip1:ip2,jp),format=cformat

  endif



  if (nread gt 5) then goto, g99

  goto, g11



; end of input file



  g99: free_lun,iunit



  print,nread,format='(/,"Nread=",i4)'



  end