a = addfile("era40.pl.t85.tuvo.200001.nc","r") nt = 0 ; time index nl = 22 ; level index u = a->U(nt,nl,:,:) v = a->V(nt,nl,:,:) t = a->T(nt,nl,:,:) wks = gsn_open_wks("x11" ,"overlay3a") res = True contours = gsn_csm_contour_map(wks,t,res) vectors = gsn_csm_vector(wks,u,v,res) overlay(contours,vectors) draw(contours) frame(wks)