<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Jan 20, 2010, at 3:27 AM, Jason Snyder wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><p>I just need to find access to TOMS, MODIS, ACE data which shows dust/sulfate aerosols. I do not care which data set it is. I tried using the GODDARD data and it would not display in GrADS becuase of some time compatibility issue. The website for this is:<br> <br><a href="http://portal.nccs.nasa.gov/cgi-lats4d/webform.cgi?&i=GEOS-5/yotc/0.25_deg/assim/inst3_3d_aer_Nv">http://portal.nccs.nasa.gov/cgi-lats4d/webform.cgi?&i=GEOS-5/yotc/0.25_deg/assim/inst3_3d_aer_Nv</a><br></p></blockquote><div>Jason,</div><div> I can't speak to the portal.nccs.nasa.gov site, but there is another Goddard site, called Giovanni, that has *some* of the data you seem to be looking for. That site is at: <a href="http://giovanni.gsfc.nasa.gov">http://giovanni.gsfc.nasa.gov</a></div><div> Giovanni has a number of different portals or "instances" as we call them. I suggest you start with the Aerosol Daily instance: </div><div><a href="http://gdata1.sci.gsfc.nasa.gov/daac-bin/G3/gui.cgi?instance_id=aerosol_daily">http://gdata1.sci.gsfc.nasa.gov/daac-bin/G3/gui.cgi?instance_id=aerosol_daily</a></div><div>which includes MODIS Daily, OMI Daily, MISR Daily and GOCART models. GOCART includes specific parameters for dust and sulfate, but our holdings only go up to 2007.</div><div> We have TOMS data in the TOMS instance, but it only goes up to 2005. However, there are more recent aerosols from the follow-on OMI instrument. There is also MISR data. We do not have any ACE data, however.</div><div><br></div><div>To obtain data downloads for GrADS, select the "Lat-Lon map Time-averaged" Visualization. If you want daily files, you will have to do this with single-day time slices in the Temporal window. Run "Generate Visualization". In the results screen, you will see a Download Data tab. Click on that to see the Download Data screen. Then click the NCD box in the Two Dimensional Map Plot section, then click Download in Batch. (Due to a bug, you have to use Download in Batch, even if you only want one file). This will give you a tar file of NetCDF files that are readable in GrADS using the sdfopen command. (However, they do not include a time coordinate so you will have set that yourself to compare with other datasets.)</div><div><br></div><div>Here is a an example of sdfopen on a Giovanni-downloaded data file.</div><div><br></div><div><div>ga-> sdfopen MOD08_D3.A2009003.005.2009011045601.pscs_000500347353.Optical_Depth_Land_And_Ocean_Mean.G3.gridSubsetter.nc</div><div>Scanning self-describing file: MOD08_D3.A2009003.005.2009011045601.pscs_000500347353.Optical_Depth_Land_And_Ocean_Mean.G3.gridSubsetter.nc</div><div>SDF file has no discernable time coordinate -- using default values.</div><div>SDF file MOD08_D3.A2009003.005.2009011045601.pscs_000500347353.Optical_Depth_Land_And_Ocean_Mean.G3.gridSubsetter.nc is open as file 1</div><div>LON set to 83.5 140.5 </div><div>LAT set to 16.5 48.5 </div><div>LEV set to 0 0 </div><div>Time values set: 1:1:1:0 1:1:1:0 </div><div>E set to 1 1 </div><div>ga-> q file 1</div><div>File 1 : </div><div> Descriptor: MOD08_D3.A2009003.005.2009011045601.pscs_000500347353.Optical_Depth_Land_And_Ocean_Mean.G3.gridSubsetter.nc</div><div> Binary: MOD08_D3.A2009003.005.2009011045601.pscs_000500347353.Optical_Depth_Land_And_Ocean_Mean.G3.gridSubsetter.nc</div><div> Type = Gridded</div><div> Xsize = 58 Ysize = 33 Zsize = 1 Tsize = 1 Esize = 1</div><div> Number of Variables = 1</div><div> optical_depth_l 0 y,x Aerosol Optical Thickness at 0.55 microns for both Ocean (best) and Land (corrected): Mean</div><div>ga-> set gxout shaded</div><div>ga-> d optical_depth_lContouring: 0 to 3.5 interval 0.5 </div><div><br></div><div>CAUTION: Please be careful about comparing aerosol parameters with each other or with models. Sometimes two apparently similar parameters measure very different things (e.g., AOD vs. UV Aerosol Index), or measure them at different times during the day, which can produce a significant sampling bias.</div></div><blockquote type="cite"><p> <br>What other data sets are available. Unfortunately, I am running grads from a Windows based PC and do not have much of any resources to use in which to produce fortran programs for reformatting data sets (I am trying to get linux configured on my computer) so I need to access ready to use data in netcd format. I am trying to display this with NCEP data, which has time steps ending on 0 hours Z, therefore, I need to aerosol data that way. I currently have aerosol data from the above website but unfortunately it ends on 3 hours z. How am I able to modify this file given my computational resources at the moment? Is it possible to do so? Anyway, please help me out with this. Anyway, help would really greatly be appreciated, whether in the form of using the above website, modifying the file I have, or accessing ready to use aerosol files. Again I am trying to examine aerosol files from both Asia and also southern California. <br> <br>Thanks,<br> <br>Jason</p></blockquote></div><br><div> <div style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><div>--</div> <div>Christopher Lynnes NASA/GSFC, Code 610.2 301-614-5185</div> </div> </div><br></body></html>