<div dir="ltr"><div><div><div>Hallo NCL,<br></div>Im just wondering why the output of the interpolation filed are missing in the last latitude (south and north poles: 87.5-90). The input data is bellow:<br><br>netcdf MERRA.U.1979.plev {<br>dimensions:<br>        time = 365 ;<br>        levels = 42 ;<br>        latitude = 144 ;<br>        longitude = 288 ;<br>variables:<br>        float U(time, levels, latitude, longitude) ;<br>                U:long_name = &quot;Eastward wind component&quot; ;<br>                U:_FillValue = 1.e+15f ;<br>                U:comments = &quot;Unknown1 variable comment&quot; ;<br>                U:grid_name = &quot;grid-1&quot; ;<br>                U:time_statistic = &quot;average&quot; ;<br>        double time(time) ;<br>                time:standard_name = &quot;time&quot; ;<br>                time:units = &quot;hours since 1979-01-01 12:00:00&quot; ;<br>                time:calendar = &quot;standard&quot; ;<br>        double levels(levels) ;<br>                levels:standard_name = &quot;air_pressure&quot; ;<br>                levels:long_name = &quot;Level&quot; ;<br>                levels:units = &quot;hPa&quot; ;<br>                levels:positive = &quot;down&quot; ;<br>                levels:axis = &quot;Z&quot; ;<br>        double latitude(latitude) ;<br>                latitude:standard_name = &quot;latitude&quot; ;<br>                latitude:long_name = &quot;Latitude&quot; ;<br>                latitude:units = &quot;degrees_north&quot; ;<br>                latitude:axis = &quot;Y&quot; ;<br>        double longitude(longitude) ;<br>                longitude:standard_name = &quot;longitude&quot; ;<br>                longitude:long_name = &quot;Longitude&quot; ;<br>                longitude:units = &quot;degrees_east&quot; ;<br>                longitude:axis = &quot;X&quot; ;<br><br><br></div>My script is:<br><br>oad &quot;$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl&quot;<br>load &quot;$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl&quot; <br>load &quot;$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl&quot; <br><br>begin<br><br>;===========2.5x2.5=============<br><br>  xlat = fspan(-90.,90,73)<br>  xlon = fspan(0.,357.5,144)<br>  xlat@units = &quot;degrees_north&quot;<br>  xlon@units = &quot;degrees_east&quot;<br><br>;===============================<br><br>do y =1979,1979<br>  print(y)<br><br>  f  = addfile (&quot;MERRA.U.&quot;+y+&quot;.<a href="http://plev.nc">plev.nc</a>&quot; , &quot;r&quot;)<br><br>    u   = f-&gt;U<br>    u   = lonFlip(u)<br><br>printVarSummary(u) <br><br>print(&quot;=====================Process=========================&quot;)<br><br>  U = linint2(u&amp;longitude,u&amp;latitude,u,True,xlon,xlat,0)<br><br><br>  U!0   = &quot;time&quot;<br>  U!1   = &quot;level&quot;<br>  U!2   = &quot;lat&quot;<br>  U!3   = &quot;lon&quot;<br>  U&amp;lat = xlat<br>  U&amp;lon = xlon<br>  U&amp;time  = u&amp;time<br>  U&amp;level = u&amp;levels<br><br></div><div>printVarSummary(U)<br><br></div>Thank you<br></div>