res                     = True
  res@gsnMaximize         = True         ; Maximize size of plot in frame
  res@gsnSpreadColors     = True         ; Use full colormap, but startblw
;  res@gsnSpreadColorStart = 24           ; at color index 24.

  res@sfXArray            = grid_lont        ; Required to tell NCL where to
  res@sfYArray            = grid_latt        ; overlay data on globe.

  res@cnFillOn            = True         ; Turn on contour fill
  res@cnFillMode          = "AreaFill"   ; Style of fill. You can also
                                         ; use "CellFill" and "RasterFill"
  res@cnLinesOn           = False        ; Turn off contour lines
  res@cnLineLabelsOn      = False        ; Turn off contour line labels

  res@cnInfoLabelOn = False

  res@cnLevelSelectionMode = "ManualLevels"       ; manually set the contour levels with the following 3 resources
  res@cnMinLevelValF  = 0.1                     ; set the minimum contour level
  res@cnMaxLevelValF  = 1.2                     ; set the maximum contour level
  res@cnLevelSpacingF = .1

  res@lbLabelAutoStride   = True         ; Clean up labelbar labels.
  res@lbBoxLinesOn        = False        ; Turn of labelbar box lines.

;  res@gsnSColors  = True

;  res@tiMainString        = "FV3 AOD 550nm"    ; Title

;  contour = gsn_csm_contour(wks,temp,res)     ; Draw a contour plot.

  res@mpProjection          = "Orthographic"
;  res@mpProjection = "LambertEqualArea"
  res@mpDataBaseVersion     = "MediumRes"      ; Improve the resolution
                                               ; of the map outlines 
                                               ; Default is "LowRes".

  res@mpPerimOn             = False       ; Turn off map perimeter
  res@mpCenterLatF          =  45.         ; Rotate map.
  res@mpCenterLonF          =  -100.

  res@pmTickMarkDisplayMode = "Always"    ; Turn on map tickmarks

  res@gsnDraw = False
  res@gsnFrame = False

;  res@gsnSColors  = True

;  res@tiMainString        = "FV3 AOD 550nm"    ; Title

;  contour = gsn_csm_contour(wks,temp,res)     ; Draw a contour plot.

  plot = gsn_csm_contour_map(wks,aqual,res)

  plot_ov1 = gsn_csm_contour(wks,aquao,res)
  overlay(plot,plot_ov1)
  plot_ov2 = gsn_csm_contour(wks,aquad,res)
  overlay(plot,plot_ov2)

  plot_ov3 = gsn_csm_contour(wks,terral,res)
  overlay(plot,plot_ov3)
  plot_ov4 = gsn_csm_contour(wks,terrao,res)
  overlay(plot,plot_ov4)

;  res@lbLabelAutoStride   = True         ; Clean up labelbar labels.
;  res@lbBoxLinesOn        = False        ; Turn of labelbar box lines.

  plot_ov5 = gsn_csm_contour(wks,terrad,res)
  overlay(plot,plot_ov5)

  draw(plot)
  frame(wks)