;*************************************************
; Mankendall_2.ncl
;
; Concepts illustrated:
;   - Calculating the mankendall trend at each grid point for four season
;   - Copying attributes from one variable to another
;   - Drawing color-filled contours 
;
;*************************************************
;
; These files are loaded by default in NCL V6.2.0 and newer
; load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
; load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
; load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"

;=============================================================
begin
;*************************************************************
;open file and read data
;**************************************************************
   diri = "./"
   fili = "anojjashadsst_1950-2019.nc"
   in = addfile(diri+fili, "r")
   sst = in->sst
   printVarSummary(sst)
;**************************************************************
;***************************************************************************
; Mankendall trend
;**************************************************************************
   p=trend_manken(sst,False,0)
   copy_VarCoords(sst(0,:,:),p(0,:,:))
   p!0 = "prob_trend"
   printVarSummary(p)
   
; ************************************************
; plotting parameters 
;************************************************
;************************************************
; resource list for first data array
;************************************************
  wks = gsn_open_wks("png","mankendall_trendjjas")         ; send graphics to PNG file
  
  res = True
  res@mpFillOn     = False
  res@mpMaxLatF    = 30.                      ; specify the plot domain
  res@mpMinLatF    = -30.                      ;                         
  res@mpMinLonF    = 40.                     ;
  res@mpMaxLonF    = 120.                     ;
  res@mpOutlineOn  = True	              ; turn the map outline on
  res@gsnDraw      =  False                   ; do not draw the plot
  res@gsnFrame     =  False                   ; do not advance the frame
  
  res@cnLevelSelectionMode = "ManualLevels" ; use explicit levels
  res@cnMinLevelValF       = -0.02
  res@cnMaxLevelValF       =  0.02
  res@cnLevelSpacingF	   =  0.001
  res@cnLineLabelsOn       = False            ; do not use line labels
  res@cnFillOn             = True             ; color fill
  res@cnLinesOn            = False            ; do not draw contour lines
  res@cnFillPalette        = "MPL_RdylGn"

  res@tiMainString = "SST_Trend_JF"            ; set the main title
  
 sres                      = True              ; set up a second resource list
  sres@gsnDraw              = False             ; do not draw the plot
  sres@gsnFrame             = False             ; do not advance the frame
  sres@cnLevelSelectionMode = "ManualLevels"  ; use explicit levels
  sres@cnMinLevelValF       = 0
  sres@cnMaxLevelValF       = 0.05

  plot    = gsn_csm_contour_map(wks,p(1,:,:),res)   ; create the temperature plot
 plot_ov = gsn_csm_contour(wks,p(0,:,:),sres)      ; create the U-wind plot

 overlay(plot,plot_ov)                       ; overlay the U-wind plot on the temperature plot
  draw(plot)                                  ; draw the temperature plot (with the U-wind plot overlaid)
  frame(wks)                                  ; advance the frame
end