;************************************************
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl" 
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"    
;************************************************
begin
;************************************************
; open netCDF file
;************************************************
  a = addfile("Aug_35yr.nc","r")
;************************************************
; Read in variable(s)
;************************************************
  var    = a->cz(0,:,:)
  var@lat2d = a->lat
  var@lon2d = a->lon
;************************************************
; create plot
;************************************************
  wks = gsn_open_wks("png","raster")          ; open a ps file
  gsn_define_colormap(wks, "MPL_RdPu") 
  res                  = True                ; plot mods desired
 
;===================================
; you can have the contour lines on in raster mode, but their thickness
; actually make the plot look like is was contoured normally.

  res@cnFillOn         = True               ; color Fill 
  res@cnFillMode       = "CellFill"       ; Raster Mode
  res@cnLinesOn        =  False             ; Turn off contour lines
;================================
; these three resources make the continents look nice. The first two
; make them color, and the later adds continental outlines when
; raster mode is used.

  res@cnLineDrawOrder  = "Predraw"          ; Draw lines and filled
  res@cnFillDrawOrder  = "Predraw"          ; areas before map gets set
;=================================
  ;res@cnLevelSelectionMode = "ManualLevels" ; set manual contour levels
  ;res@cnMinLevelValF   = -2.0               ; set min contour level
  ;res@cnMaxLevelValF   =  0.0               ; set max contour level
  ;res@cnLevelSpacingF  =  0.5               ; set contour spacing

  res@mpLandFillColor  = -1    ; choose color of continents.
                                            ; must be in colormap 
  res@cnMissingValFillColor="white"
;;;;;;;;;;;;;;;;;;;;;;;;;;
  res@gsnAddCyclic = False
;;;;;;;;;;;;;;ZOOM
  res@mpMinLatF = 0.
  res@mpMaxLatF = 55. 
  res@mpMinLonF = 80.
  res@mpMaxLonF = 195.
  res@mpCenterLonF = 137.5 
  

  res@pmTickMarkDisplayMode = "Always" ; 默认是每隔5°出现一次坐标数字 

 

  res@gsnLeftString  = ""
;===================================


  plot = gsn_csm_contour_map(wks,var,res) ; create plot
  
  
end