a = addfile("era40.pl.t85.tuvo.200001.nc","r") nt = 0 ; time index nl = 22 ; level index u = a->U(nt,nl,:,:) ; 2D , 128 x 256 v = a->V(nt,nl,:,:) t = a->T(nt,nl,:,:) wks = gsn_open_wks("x11" ,"overlay3a") res = True ; use this for common resources res@gsnLeftString = "" ; turn off left and right strings res@gsnRightString = "" res@gsnDraw = False ; don't draw the individual plots res@gsnFrame = False ; turn off frame advance vcres = res ; Copy common resources to vector resource cnres = res ; Copy common resources to contour resource vcres@gsnAddCyclic = True ; adds longitude cyclic point vcres@vcRefLengthF = 0.06 ; increase reference length for vectors vcres@vcMinDistanceF = 0.01 ; thin the vectors cnres@cnFillOn = True ; turn on color fill vcres@vcRefAnnoOrthogonalPosF = -0.5 ; move reference anno box into the plot vcres@vcRefAnnoString2On = False ; turn off "reference cnres@cnFillPalette = "NCV_manga" ; change the color map contours = gsn_csm_contour_map(wks,t,cnres) vectors = gsn_csm_vector(wks,u,v,vcres) overlay(contours,vectors) draw(contours) frame(wks)