<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi, Jim -- <div>A vertical coordinate that has units of "1" will not be recognized as a Z axis by the sdfopen code. You need a more meaningful unit, something the udunits library utility utScan can make sense of, or one of the following: hybrid_sigma_pressure, mb, millibar, sigma_level, level, layer, layers, degreesk, or degrees_k. If all those fail, sdfopen will look for an attribute named "axis" with a value of Z or z. Otherwise, you have to use xdfopen to nominate 'lev' as your Z dimension. </div><div>--Jennifer<br><div><div><br><div><div>On Jan 10, 2012, at 2:32 PM, James T. Potemra wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Probably for the developers...<br><br>I've noticed that GrADS seems to care about the units attributed to the <br>vertical co-ordinate in netCDF files. In particular, I am having <br>problems accessing a file via OPeNDAP that has a vertical co-ordinate of <br>"lev" with units of "1". I believe this is ok with respect to CF <br>compliance (this is for model output on non-z vertical levels), however <br>GrADS will not show variables that have such a unit on the vertical <br>dimension.<br><br>As an example, I've created two netCDF files with dimensions lat, lon, <br>time and lev; and three variables ssh(time,lat,lon), u(time,lev,lat,lon) <br>and v(time,lev,lat,lon). In one file the units of "lev" are "1", and <br>using sdfopen to read this file gives only one variable, ssh, which is <br>not dependent on the vertical co-ordinate. In the other file, with <br>units of "meters", I can see all three variables. The particulars are <br>included below. My question is whether this can be overcome without use <br>of a control file and xdfopen? Thanks,<br><br>Jim<br><br>----------------------------------------------------<br>Config: v2.0.a9 little-endian readline printim grib2 netcdf hdf4-sds <br>hdf5 opendap-grids,stn geotiff shapefile<br>(running on Linux lii 2.6.18-274.3.1.el5 #1 SMP Fri Aug 26 18:49:02 EDT <br>2011 x86_64 x86_64 x86_64 GNU/Linux)<br>same issue using<br>Config: v2.0.a9.oga.1 little-endian readline printim grib2 netcdf <br>hdf4-sds hdf5 opendap-grids,stn athena geotiff shapefile<br>----------------------------------------------------<br><br>sample file 1 with dimensions of "1" on vertical co-ordinate:<br><br>ga-> sdfopen sample_tide1.nc<br>Scanning self-describing file: sample_tide1.nc<br>SDF file sample_tide1.nc is open as file 1<br>LON set to 118 290<br>LAT set to -66 66<br>LEV set to 0 0<br>Time values set: 2012:1:1:0 2012:1:1:0<br>E set to 1 1<br>ga-> q file<br>File 1 :<br> Descriptor: sample_tide1.nc<br> Binary: sample_tide1.nc<br> Type = Gridded<br> Xsize = 87 Ysize = 67 Zsize = 1 Tsize = 24 Esize = 1<br> Number of Variables = 1<br> ssh 0 t,y,x tidal elevation<br>ga-><br><br>----------------------------------------------------<br><br>sample file 2 with dimensions of "meters" on vertical co-ordinate:<br><br>ga-> sdfopen sample_tide2.nc<br>Scanning self-describing file: sample_tide2.nc<br>SDF file sample_tide2.nc is open as file 1<br>LON set to 118 290<br>LAT set to -66 66<br>LEV set to 0 0<br>Time values set: 2012:1:1:0 2012:1:1:0<br>E set to 1 1<br>ga-> q file<br>File 1 :<br> Descriptor: sample_tide2.nc<br> Binary: sample_tide2.nc<br> Type = Gridded<br> Xsize = 87 Ysize = 67 Zsize = 1 Tsize = 24 Esize = 1<br> Number of Variables = 3<br> ssh 0 t,y,x tidal elevation<br> u 1 t,z,y,x u-velocity component<br> v 1 t,z,y,x v-velocity component<br>ga-><br><br>----------------------------------------------------<br><br>ncdump on file 1:<br><br>netcdf sample_tide1 {<br>dimensions:<br> lon = 87 ;<br> lat = 67 ;<br> time = 24 ;<br> lev = 1 ;<br>variables:<br> double lon(lon) ;<br> lon:units = "degrees_east" ;<br> lon:long_name = "Longitude" ;<br> lon:standard_name = "longitude" ;<br> double lat(lat) ;<br> lat:units = "degrees_north" ;<br> lat:long_name = "Latitude" ;<br> lat:standard_name = "latitude" ;<br> double time(time) ;<br> time:long_name = "Time" ;<br> time:units = "minutes since 2012-01-01 00:00" ;<br> double ssh(time, lat, lon) ;<br> ssh:_FillValue = -999.99 ;<br> ssh:units = "meters" ;<br> ssh:long_name = "tidal elevation" ;<br> ssh:standard_name = "sea_surface_height" ;<br> ssh:missing_value = -999.99f ;<br> double lev(lev) ;<br> lev:units = "1" ;<br> lev:long_name = "Level" ;<br> lev:positive = "down" ;<br> double u(time, lev, lat, lon) ;<br> u:_FillValue = -999.99 ;<br> u:units = "meter second-1" ;<br> u:long_name = "u-velocity component" ;<br> u:standard_name = "eastward_sea_water_velocity" ;<br> u:missing_value = -999.99f ;<br> double v(time, lev, lat, lon) ;<br> v:_FillValue = -999.99 ;<br> v:units = "meter second-1" ;<br> v:long_name = "v-velocity component" ;<br> v:standard_name = "northward_sea_water_velocity" ;<br> v:missing_value = -999.99f ;<br><br>----------------------------------------------------<br><br>ncdump on file 2:<br><br>netcdf sample_tide2 {<br>dimensions:<br> lon = 87 ;<br> lat = 67 ;<br> time = 24 ;<br> lev = 1 ;<br>variables:<br> double lon(lon) ;<br> lon:units = "degrees_east" ;<br> lon:long_name = "Longitude" ;<br> lon:standard_name = "longitude" ;<br> double lat(lat) ;<br> lat:units = "degrees_north" ;<br> lat:long_name = "Latitude" ;<br> lat:standard_name = "latitude" ;<br> double time(time) ;<br> time:long_name = "Time" ;<br> time:units = "minutes since 2012-01-01 00:00" ;<br> double ssh(time, lat, lon) ;<br> ssh:_FillValue = -999.99 ;<br> ssh:units = "meters" ;<br> ssh:long_name = "tidal elevation" ;<br> ssh:standard_name = "sea_surface_height" ;<br> ssh:missing_value = -999.99f ;<br> double lev(lev) ;<br> lev:units = "meters" ;<br> lev:long_name = "Level" ;<br> lev:positive = "down" ;<br> lev:standard_name = "model_level_number" ;<br> double u(time, lev, lat, lon) ;<br> u:_FillValue = -999.99 ;<br> u:units = "meter second-1" ;<br> u:long_name = "u-velocity component" ;<br> u:standard_name = "eastward_sea_water_velocity" ;<br> u:missing_value = -999.99f ;<br> double v(time, lev, lat, lon) ;<br> v:_FillValue = -999.99 ;<br> v:units = "meter second-1" ;<br> v:long_name = "v-velocity component" ;<br> v:standard_name = "northward_sea_water_velocity" ;<br> v:missing_value = -999.99f ;<br><br><br><br>,<br>_______________________________________________<br>gradsusr mailing list<br><a href="mailto:gradsusr@gradsusr.org">gradsusr@gradsusr.org</a><br>http://gradsusr.org/mailman/listinfo/gradsusr<br></div></blockquote></div><br><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>--</div><div>Jennifer M. Adams</div><div>IGES/COLA</div><div>4041 Powder Mill Road, Suite 302</div><div>Calverton, MD 20705</div><div><a href="mailto:jma@cola.iges.org">jma@cola.iges.org</a></div><div><br class="khtml-block-placeholder"></div><br class="Apple-interchange-newline"></span></span></span>
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