;--------------------------------------------------------
begin
 a  = addfile("/work/ewilliam/ncep_2016/combine/mainprf.nc","r")
 t  = a->air
 w  = a->omega
 u  = a->uwnd(0,:,:,{96})
 g  = a->hgt
 v  = a->vwnd
;-------------
 g1 = 1013*(1-6.5/288000*g)^5.255
 g1@units  = "hPa"
 copy_VarCoords(g,g1)
 ;printVarSummary(g1)
 ;print(g1)
 v  = 0.
;------------
 ;umin = (u)
 ;umax = (u)
;-----------------------------------------
 wks  = gsn_open_wks ("png", "mainplot" )          ; send graphics to PNG file

 res   = True                                     ; plot mods desired
 
 res@cnFillOpacityF = 0.4
 res@tiMainString    = "NCEP/NCAR Reanalysis Data June-September 2016 @ 96E" ; title

 res@gsnDraw              = False                ; do not draw the plot
 res@gsnFrame             = False                ; do not advance the frame
 res@cnLevelSelectionMode = "ManualLevels"       ; manually select levels
 res@cnLevelSpacingF      = 10.0                  ; contour spacing
 res@cnMinLevelValF       = 300.                 ; min level
 res@cnMaxLevelValF       = 390.                 ; max level
 res@cnLineLabelsOn       = False                 ; turn on line labels
 res@cnFillOn             = True                 ; turn on color fill
 res@cnFillPalette        = "MPL_rainbow"             ; choose colormap

 res@tiYAxisString     = "Pressure Levels (hPa)"
 res@gsnLeftString     = "Mean Potential Air Temperature"
 res@gsnRightString    = t@units

 res@vcRefMagnitudeF = 5.0                ; define vector ref mag
 res@vcRefLengthF    = 0.08              ; define length of vec ref
 res@vcGlyphStyle    = "CurlyVector"      ; turn on curly vectors
 res@vcMinDistanceF  = 0.04               ; thin out vectors
 res@vcMapDirection  = True

 res@vcLineArrowColor        = "Blue"       ; change vector color
 res@vcLineArrowThicknessF   = 2.0          ; change vector thickness
 res@vcRefAnnoArrowLineColor = "black"      ; change ref vector color
 res@vcRefAnnoArrowUseVecColor = False      ; don't use vec color for ref

 plot1  = gsn_csm_pres_hgt_vector(wks, t(0,:,:,{96}),v(0,:,:,{96}),w(0,:,:,{96}), res )
;------------------------------------------------
 sres   = True                                 ; plot mods desired
 
 sres@cnLineLabelsOn       = True              ; turn on line labels
 sres@cnLineColor          = "Red"             ; color of contour
 sres@cnInfoLabelOn        = False             ; turn off info label
 sres@gsnDraw              = False             ; do not draw the plot
 sres@gsnFrame             = False             ; do not advance the frame

 sres@gsnLeftString     = " "
 sres@gsnRightString    = " "

 plot2  = gsn_csm_pres_hgt(wks, u, sres )
;-----------------------
 mres   = True
 mres@gsnLeftString     = " "
 mres@gsnRightString    = " "
 mres@gsnDraw           = False                      ; do not draw the plot
 mres@gsnFrame          = False                      ; do not advance the frame
 mres@xyLineThicknesses = (/3.0/)                    ; make line thicker
 mres@xyLineColors      = (/"green"/)                ; change line color
 plot3  = gsn_csm_xy(wks,g1&lat,g1(0,:,{96}),mres)     ; create plot
;-----------------------------
 overlay(plot1,plot2)
 overlay(plot1,plot3)
 draw(plot1)
 frame(wks)
end