<div dir="ltr">Rick,<div>Thank you once again. wrf_gsn_8.ncl does exactly what I was trying to do. I do not know how I missed it. I spent the whole of Thursday 6th Oct. trying to make my code work.</div><div>best regards.</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Oct 7, 2022 at 7:29 AM Zilore Mumba <<a href="mailto:zmumba@gmail.com">zmumba@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Thanks Rick, I will try that example.</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Oct 6, 2022 at 10:37 PM Rick Brownrigg <<a href="mailto:brownrig@ucar.edu" target="_blank">brownrig@ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Hi Zilore,</div><div><br></div><div>There's a WRF examples page that's a bit obscurely referenced from the main examples pages:</div><div><br></div><div> <a href="http://ncl.ucar.edu/Applications/wrfgsn.shtml#ex8" target="_blank">http://ncl.ucar.edu/Applications/wrfgsn.shtml#ex8</a></div><div><br></div><div>Example #8 in particular shows how to set up the coordinates. I am not an expert at this, but hopefully there's enough there to get you going.</div><div><br></div><div>Rick</div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Oct 6, 2022 at 2:04 PM Zilore Mumba via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><br>I am wondering if there is anybody drawing streamlines with WRF output. My search has yielded nothing and my attempt has been disastrous.<br>I am having two problems:<br>1. how do I attach lon/lat units to the u, v components (check_for_y_lat_coord: Warning: Data either does not contain<br>a valid latitude coordinate array or doesn't contain one at all... errors).<br>See code pasted below.<br>2. The streamlines are drawn, but in the wrong place over a global map.<br><div>If there is anyone who is able to draw streamlines, I will appreciate to learn from them.</div><div><br></div><div>my doe so far, below</div><div>load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl" <br>load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" <br><br>begin<br>;<br>; Read in data.<br>;;;;;;;;;;;;;;<br>;<br> f = addfile("/home/zmumba/DA/OUTPUT/2022092800/noda/wrfout_d01_2022-09-28_00:00:<a href="http://00.nc" target="_blank">00.nc</a>","r")<br><br> ; What times and how many time steps are in the data set?<br> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;<br> times = wrf_user_getvar(f,"times",-1) ; get all times in the file<br> ntimes = dimsizes(times) ; number of times in the file<br><br> ; The specific pressure levels that we want the data interpolated to.<br> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;<br> pressure_levels = (/ 850., 700., 500., 300./) ; pressure levels to plot<br> nlevels = dimsizes(pressure_levels) ; number of pressure levels<br><br><br> tc = wrf_user_getvar(f,"tc",-1) ; T in C<br> u = wrf_user_getvar(f,"ua",-1) ; u averaged to mass points<br> v = wrf_user_getvar(f,"va",-1) ; v averaged to mass points<br> p = wrf_user_getvar(f, "pressure",-1) ; pressure is our vertical coordinate<br> z = wrf_user_getvar(f, "z",-1) ; grid point height<br> rh = wrf_user_getvar(f,"rh",-1) ; relative humidity<br> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;<br><br> ;lat2d = wrf_user_getvar(f,"XLAT",0)<br> ;lon2d = wrf_user_getvar(f,"XLONG",0)<br><br> lat2d = f->XLAT(0,:,:)<br> lon2d = f->XLONG(0,:,:)<br><br> lat = lat2d(:,0) ; create classic 1D coordinate arrays<br> lon = lon2d(0,:)<br><br> ;u&lat@units = "degrees_north"<br> ;u&lon@units = "degrees_east" <br> ;v&lat@units = "degrees_north"<br> ;v&lon@units = "degrees_east" <br><br> ;lat@units= "degrees_north"<br> ;lon@units= "degrees_east"<br> ;lat!0 = "lat"<br> ;lon!0 = "lon"<br> ;lat&lat = lat<br> ;lon&lon = lon<br><br><br> ;pressure = pressure_levels(level)<br> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;<br> pressure = pressure_levels(0)<br><br> tc_plane = wrf_user_intrp3d(tc,p,"h",pressure,0.,False)<br> z_plane = wrf_user_intrp3d( z,p,"h",pressure,0.,False)<br> rh_plane = wrf_user_intrp3d(rh,p,"h",pressure,0.,False)<br> u_plane = wrf_user_intrp3d( u,p,"h",pressure,0.,False)<br> v_plane = wrf_user_intrp3d( v,p,"h",pressure,0.,False)<br><br> spd = (u_plane*u_plane + v_plane*v_plane)^(0.5) ; m/sec<br> spd@description = "Wind Speed"<br> spd@units = "m/s"<br> u_plane = u_plane*1.94386 ; kts<br> v_plane = v_plane*1.94386 ; kts<br> u_plane@units = "kts"<br> v_plane@units = "kts"<br><br> wks = gsn_open_wks("x11","gsn_csm_streamline_map")<br><br> res = True<br> res@gsnAddCyclic = False<br> res@gsnMaximize = True<br> res@gsnDraw = False ; don't draw yet<br> res@gsnFrame = False ; don't advance yet<br><br> res@tiMainString = "WRF Streamlines" ; draw a title<br> res@gsnLeftString = ""<br> res@gsnRightString = ""<br> res@gsnCenterString = " "<br><br> res@mpProjection = "Mercator"<br><br> ;---Zoom in on map and plot again<br> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;<br> ;res@cnLineThicknessF = 2 ; make lines thicker, Default: 1<br> ;res@mpMinLatF = min(lat) ; zoom in on lat/lon area<br> ;res@mpMaxLatF = max(lat)<br> ;res@mpMinLonF = min(lon)<br> ;res@mpMaxLonF = max(lon)<br><br> res@mpDataBaseVersion = "MediumRes" ; better and more map outlines<br> res@mpDataSetName = "Earth..4"<br> res@mpOutlineBoundarySets = "AllBoundaries"<br> res@mpOutlineOn = True<br> res@mpNationalLineThicknessF = 2.5 ; turn on country boundaries<br><br> res@lbOrientation = "Vertical"<br> res@tiMainOffsetYF = -0.03 ; Move the title down<br><br> plot = gsn_csm_streamline_map(wks,u_plane,v_plane,res)<br><br> ;Define shapefiles<br> ;*****************<br> shp_filename = ("$HOME/DA/SCRIPTS/06_Utility_Files/Shapefiles/Lesotho/lso_admbnda_adm1_FAO_MLGCA_2019.shp")<br><br> ;Set shapefile resources<br> ;***********************<br> shpres = True<br> shpres@gsLineThicknessF = 1 ; increase line thickness<br> shpres@gsLineColor = "Black" ; line colorgsLineThicknessF<br> shpres@gsLineDashPattern = 1<br><br> shp= gsn_add_shapefile_polylines(wks,plot,shp_filename,shpres)<br><br> draw(plot)<br> frame(wks)<br>end</div></div>
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