;************************************************
; era40_1.ncl
;
; Concepts illustrated:
;   - Reading GRIB data
;   - Plotting ERA40 data
;   - Spanning the full color map for contour fill
;   - Drawing color-filled contours over a cylindrical equidistant map
;   - Selecting a different color map
;
;*************************************************
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"  
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"  
;************************************************
begin
;************************************************
; create pointer to file and read in data
;************************************************
  in = addfile("alex.grib.grib","r")

;************************************************
; create default plot
;************************************************
  wks = gsn_open_wks("x11","27_00")               ; open a ps file
;  gsn_define_colormap(wks,"BlAqGrYeOrRe")        ; choose colormap


    gsn_define_colormap(wks,"BlueYellowRed")
 
  res                       			= True 
  res2						= True
  
  ;TICKMARK RESOURCES (ON/OFF - FONT SIZE)
	res@pmTickMarkDisplayMode = "Always" 
	res@tmXTOn				= False
	res@tmXBOn				= True
	res@tmYLOn				= False
	res@tmYROn				= False
	res@tmXTLabelFontHeightF		= 0.025
	res@tmXBLabelFontHeightF		= 0.025
	res@tmYLLabelFontHeightF		= 0.025
	res@tmYRLabelFontHeightF		= 0.025
	
	res2@tmXTOn				= False
	res2@tmXBOn				= False
	res2@tmYLOn				= False
	res2@tmYROn				= False
	
  ; MAP RESOURCES.
	res@mpGridAndLimbOn			= True
	res@mpGridLineDashPattern		= 2
	res@mpGeophysicalLineColor		= "Black"
	res@mpGeophysicalLineThicknessF		= 1.5
	res@mpNationalLineColor			= "Black"	
	res@mpNationalLineThicknessF		= 1.5
	res@mpUSStateLineColor			= "Black"
	res@mpUSStateLineThicknessF		= 1.5
	res@mpPerimLineColor			= "Black"
            
  ;LABEL BAR RESOURCES
	res@lbLabelAutoStride			= True            
	res@lbOrientation			= "Vertical"
	res@lbLabelFontHeightF			= 0.025
	
  ;CONTOUR RESOURCES
	res@cnFillOn				= True             
	res@cnLinesOn				= False            
	res@cnLineLabelsOn			= False  
	res@cnLevelSelectionMode   		= "ManualLevels"
	res@cnMinLevelValF         		= 30.
	res@cnMaxLevelValF         		= -50.
	res@cnLevelSpacingF			= 5.
          
	res2@cnFillOn				= False             
	res2@cnLinesOn				= True            
	res2@cnLineLabelsOn			= True
	res2@cnLevelSelectionMode   		= "ManualLevels"
	res2@cnMinLevelValF         		= 940.
	res2@cnMaxLevelValF         		= 1044.
	res2@cnLevelSpacingF			= 4.
	res2@cnLineThicknessF			= 1.
	res2@cnInfoLabelOn			= True	
res2@cnInfoLabelOn = False


     res2@cnHighLabelsOn = True
    res2@cnLowLabelsOn = True
    res2@cnLowLabelBackgroundColor=-1
     res2@cnHighLabelFontHeightF = 0.02
     res2@cnLowLabelFontHeightF =0.04


	
  ;GSN RESOURCES
	res@gsnSpreadColors			= True               
	res@gsnLeftString			= " "
	res@gsnRightString			= " "
	res@gsnDraw				= False
	res@gsnFrame				= False
	res@gsnMaximize				= True
	
	res2@gsnDraw				= False
	res2@gsnFrame				= False
;	res2@gsnMaximize			= True
	res2@gsnLeftString			= " "
	
  ;TITLE RESOURCES
	res@tiMainOn				= False
	res@tiMainPosition			= "Center"
	res@tiMainFontHeightF			= 0.025
 
  ;PROJECTION RESOURCES
	res@tfDoNDCOverlay 			= False 
	res@gsnAddCyclic 			= False
 	res@mpProjection			= "Stereographic"
	res@mpLimitMode				= "Corners"
        res@mpLeftCornerLatF                  = 65.2
        res@mpLeftCornerLonF                  = 132.8014
        res@mpRightCornerLatF                 = 63.8
        res@mpRightCornerLonF                 = -45.0
  	res@mpCenterLatF 			= 90
  	res@mpCenterLonF 			= -180
	
	res2@tfDoNDCOverlay 			= False 
	res2@gsnAddCyclic 			= False
 	res2@mpProjection			= "Stereographic"
	res2@mpLimitMode				= "Corners"
        res2@mpLeftCornerLatF                  = 65.2
        res2@mpLeftCornerLonF                  = 132.8014
        res2@mpRightCornerLatF                 = 63.8
        res2@mpRightCornerLonF                 = -45.0
  	res2@mpCenterLatF 			= 90
  	res2@mpCenterLonF 			= -180


pres = in->MSL_GDS0_SFC(72,:,:)
 var2 = pres
var2 = (/ pres/100  /) 
 var = in->2T_GDS0_SFC(72,:,:)
var = var-273

 
  plot			= gsn_csm_contour_map(wks,var,res)
  plot2			= gsn_csm_contour(wks,var2,res2)
  overlay(plot,plot2)
  draw(plot)
  frame(wks)

end