<div dir="ltr">Dear All,<div><br></div><div>I am trying to read the CMIP5 HADGEM-AO GCM (nc file) data sets using grads. I have prepared a descriptor file. However, it seems the file is not read correctly, and I receive wrong temperature values.</div><div><br></div><div>The GCM attributes are:</div><div><br></div><div><div>netcdf tasmax_day_HadGEM2-AO_rcp45_r1i1p1_20060101-21001230 {</div><div>dimensions:</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>time = UNLIMITED ; // (34200 currently)</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>lat = 145 ;</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>lon = 192 ;</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>bnds = 2 ;</div><div>variables:</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>double time(time) ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>time:bounds = &quot;time_bnds&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>time:units = &quot;days since 2006-01-01&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>time:calendar = &quot;360_day&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>time:axis = &quot;T&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>time:long_name = &quot;time&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>time:standard_name = &quot;time&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>double time_bnds(time, bnds) ;</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>double lat(lat) ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lat:bounds = &quot;lat_bnds&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lat:units = &quot;degrees_north&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lat:axis = &quot;Y&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lat:long_name = &quot;latitude&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lat:standard_name = &quot;latitude&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>double lat_bnds(lat, bnds) ;</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>double lon(lon) ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lon:bounds = &quot;lon_bnds&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lon:units = &quot;degrees_east&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lon:axis = &quot;X&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lon:long_name = &quot;longitude&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>lon:standard_name = &quot;longitude&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>double lon_bnds(lon, bnds) ;</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>double height ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>height:units = &quot;m&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>height:axis = &quot;Z&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>height:positive = &quot;up&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>height:long_name = &quot;height&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>height:standard_name = &quot;height&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">        </span>float tasmax(time, lat, lon) ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:standard_name = &quot;air_temperature&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:long_name = &quot;Daily Maximum Near-Surface Air Temperature&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:comment = &quot;daily-maximum near-surface (usually, 2 meter) air temperature.&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:units = &quot;K&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:original_name = &quot;TASMAX&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:cell_methods = &quot;time: maximum (interval: 1.000000 days)&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:cell_measures = &quot;area: areacella&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:history = &quot;2012-10-29T09:05:42Z altered by CMOR: Treated scalar dimension: \&#39;height\&#39;. 2012-10-29T09:05:42Z altered by CMOR: replaced missing value flag (-1.07374e+09) with standard missing value (1e+20).&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:coordinates = &quot;height&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:missing_value = 1.e+20f ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:_FillValue = 1.e+20f ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>tasmax:associated_files = &quot;baseURL: <a href="http://cmip-pcmdi.llnl.gov/CMIP5/dataLocation">http://cmip-pcmdi.llnl.gov/CMIP5/dataLocation</a> gridspecFile: gridspec_fx_HadGEM2-AO_rcp45_r0i0p0.nc areacella: areacella_fx_HadGEM2-AO_rcp45_r0i0p0.nc&quot; ;</div><div><br></div><div>// global attributes:</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>:institution = &quot;NIMR (National Institute of Meteorological Research, Seoul, South Korea)&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>:institute_id = &quot;NIMR-KMA&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>:experiment_id = &quot;rcp45&quot; ;</div><div><span class="Apple-tab-span" style="white-space:pre">                </span>:source = &quot;HadGEM2-AO r6.6.3 (2010): atmosphere:  HadGAM (HadGAM2, N96L38); atm: HadGOM (HadGOM2, 1x1L40, increased res at Equator); sea ice: part of HadGOM2; land: MOSES-2&quot; ;</div></div><div><br></div><div><br></div><div>The descriptor (.ctl) file :</div><div><br></div><div><div>DSET ^tasmax_day_HadGEM2-AO_rcp45_r1i1p1_20060101-21001230.nc</div><div>TITLE Air Temperature</div><div>DTYPE netcdf</div><div>OPTIONS 365_day_calender</div><div>UNDEF 1.e+20f</div><div>xdef 192 linear 0 1.875</div><div>ydef 145 linear -90 1.25</div><div>zdef 1 levels 1013.0</div><div>tdef 34200 linear 00Z1Jan2006 1dy</div><div>VARS 1</div><div>tasmax 1 t,z,y,x Air Temperature [K]</div><div>ENDVARS<br><br></div></div><div><br></div><div><br></div><div>Kindly, help in understanding where we are doing wrong.</div><div><br></div><div>Much appreciate your help in this. </div><div><br></div><div><br></div><div>Regards,</div><div>Itesh Dash</div><div>RIMES</div></div>