;***********************
; h_lat_8.ncl
;***********************
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
;***********************
begin
  f     = addfile ("mxclim.nc","r")
  u     = f->U(0,:,:)                              ; get u for January
;***********************
; Create  Plot
;***********************
  wks   = gsn_open_wks ("ps", "h_lat" )           ; open workstation
  gsn_define_colormap(wks,"BlWhRe")               ; choose colormap


  res                      = True                 ; plot mods desired

  res@cnLevelSelectionMode = "ManualLevels"       ; manually select levels
  res@cnLevelSpacingF      = 5.0                  ; contour spacing
  res@cnMinLevelValF       = -50.                 ; min level
  res@cnMaxLevelValF       =  50.                 ; max level
  res@cnLineLabelsOn       = True                 ; turn on line labels
  res@cnFillOn             = True                 ; turn on color fill

;---This resource not needed in V6.1.0
  res@gsnSpreadColors      = True                 ; use full range of map

;---This resource defaults to True in NCL V6.1.0
  res@lbLabelAutoStride    = True                 ; optimal labels

  res@tmYRMode             = "Automatic"          ; turn off special labels on right axis

; note u is already on pressure levels. If this were model data, it
; would be necessary to interpolate from the hybrid coordinates to 
; pressure levels.
  
  plot  = gsn_csm_pres_hgt(wks, u, res )   ; plaace holder
  
end