begin f = addfile ("ruc2.bgrb.20020418.i12.f00.grb","r") vpt = f->VPTMP_252_HYBL(0,:,:) lat2d = f->gridlat_252 ; 2D latitude grid lon2d = f->gridlon_252 ; 2D longitude grid vpt@lat2d = lat2d ; Must attach lat2d and vpt@lon2d = lon2d ; lon2d as special attributes. wks = gsn_open_wks("png","contour6d") ; Open "contour6d.png" png file. res = True ; Plot options desired. res@cnFillOn = True ; Turn on contour fill res@cnLinesOn = False ; Contour lines off res@cnFillPalette = "gui_default" ; Set color map res@mpLimitMode = "Corners" ; Choose range of map. res@mpLeftCornerLatF = lat2d@corners(0) res@mpLeftCornerLonF = lon2d@corners(0) res@mpRightCornerLatF = lat2d@corners(2) res@mpRightCornerLonF = lon2d@corners(2) ; ; Native lambert grids read in from grib files are different than ; those read in from netCDF files. NCL automatically looks for the ; parallel and meridian information on the grib file and attaches ; this information as attributes to the lon2d array. ; res@mpProjection = "LambertConformal" res@mpLambertParallel1F = lon2d@Latin1 res@mpLambertParallel2F = lon2d@Latin2 res@mpLambertMeridianF = lon2d@Lov plot = gsn_csm_contour_map(wks,vpt,res) ; Call gsn_csm function for ; drawings contours over a map. end