<div dir="ltr">Thanks guys for your response. I took time to try all your suggestions and learnt something new in one way or another. Jennifer's suggestions really worked in my case. <div><br></div><div style>regards</div>
<div style><br></div><div style>Joshua</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, May 29, 2013 at 7:15 PM, Jennifer Adams <span dir="ltr"><<a href="mailto:jma@cola.iges.org" target="_blank">jma@cola.iges.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word">If a netcdf file doesn't have a time dimension, GrADS will assign a default time of 00z01jan0001 to the file. That message is not an error, it is a warning -- the file was opened successfully. If you want the default time to be something else, use a simple xdfopen-style descriptor to assign a time. If you want to merge files over the time dimension, you can use templating with the CHSUB option -- mapping each file to its particular time -- the strings in the filenames are not readily interpreted, so the usual date string substitutions won't work. <div>
<br></div><div><a href="http://iges.org/grads/gadoc/SDFdescriptorfile.html" target="_blank">http://iges.org/grads/gadoc/SDFdescriptorfile.html</a><br><div><a href="http://iges.org/grads/gadoc/templates.html" target="_blank">http://iges.org/grads/gadoc/templates.html</a></div>
<div><br></div><div>--Jennifer<br><div><br><div><div><div class="h5"><div>On May 29, 2013, at 8:08 AM, Joshua Ngaina wrote:</div><br></div></div><blockquote type="cite"><div><div class="h5"><div dir="ltr"><div><br>
</div><div><b>Dear All,<br><br></b></div><div><b>I have daily MODIS aerosol products (Small mode fraction). <br><br></b></div><div><b>I wanted to merge these files using CDO but it seemed the files were not merged. </b><br>
<br>met@met-HP-Compaq-6000-Pro-MT-PC:/media/BERTH/MODIS_DAILY$ cdo mergetime *.nc ALLMOD08.nc<br>cdo mergetime: Processed 4147200 values from 64 variables over 32 timesteps. ( 0.18s )<br><b><br>
So to check one of the files, I used grads and I got this error: <span>DF</span> <span>file</span> <span>has</span> <span>no</span> <span>discernable</span> <span>time</span> <span>coordinate</span> -- <span>using</span> <span>default</span> <span>values</span></b>. <br>
<br>ga-> sdfopen <a href="http://MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc/" target="_blank">MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc</a><br>
Scanning self-describing file: <a href="http://MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc/" target="_blank">MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc</a><br>
SDF file has no discernable time coordinate -- using default values.<br>SDF file <a href="http://MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc/" target="_blank">MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc</a> is open as file 1<br>
LON set to 0 360 <br>LAT set to -89.5 89.5 <br>LEV set to 0 0 <br>Time values set: 1:1:1:0 1:1:1:0 <br>E set to 1 1 <br>ga-> q file<br>File 1 : <br> Descriptor: <a href="http://MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc/" target="_blank">MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc</a><br>
Binary: <a href="http://MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc/" target="_blank">MOD08_D3.A2001001.051.2010286151047.pscs_000500504418.Optical_Depth_Ratio_Small_Land_And_Ocean_Mean.G3.nc</a><br>
Type = Gridded<br> Xsize = 360 Ysize = 180 Zsize = 1 Tsize = 1 Esize = 1<br> Number of Variables = 2<br> optical_depth_l 0 y,x Aerosol Optical Thickness at 0.55 microns for both Ocean (best) and Land (corrected): Mean<br>
optical_depth_r 0 y,x Ratio of small mode aerosol optical depth at 0.55 micron for both land and ocean: Mean<br><b><br></b></div><div><b>I also checked the merged netcdf file </b><br><br>ga-> sdfopen ALLMOD08.nc <br>
Scanning self-describing file: ALLMOD08.nc<br>SDF file has no discernable time coordinate -- using default values.<br>SDF file ALLMOD08.nc is open as file 1<br>LON set to 0 360 <br>LAT set to -89.5 89.5 <br>LEV set to 0 0 <br>
Time values set: 1:1:1:0 1:1:1:0 <br>E set to 1 1 <br>ga-> q file<br>File 1 : <br> Descriptor: ALLMOD08.nc<br> Binary: ALLMOD08.nc<br> Type = Gridded<br> Xsize = 360 Ysize = 180 Zsize = 1 Tsize = 1 Esize = 1<br>
Number of Variables = 2<br> optical_depth_l 0 y,x Aerosol Optical Thickness at 0.55 microns for both Ocean (best) and Land (corrected): Mean<br> optical_depth_r 0 y,x Ratio of small mode aerosol optical depth at 0.55 micron for both land and ocean: Mean<br>
<br></div><div><b>I also noted that the dimension of both files were the same. <br><br></b></div><div><b>My major problem is with many files of this type, How do I merge this files for analysis with GrADs. Please advise<br>
</b></div><b><br></b><div>
<b><br>
Regards and Thanks,</b><br><br></div><div>Joshua Ngaina<br>
</div></div></div></div><div class="im">
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<span style="font-size:12px"><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" target="_blank">jma@cola.iges.org</a></div>
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