How to visualize MLS data with Panoply via OPeNDAP

[hyoklee]

Prerequisite


This instruction assumes the installation of the latest HDF5-OPeNDAP handler with CF option (--enable-cf) enabled. Also, MLS version 2 files will work since handler will thrown an error if it detects MLS version 1 files. MLS version 1 files have multiple lat/lon under different groups and the CF convention doesn't allow multiple lat/lon coordinate variables. The demo URL of this example is http://eosdap.hdfgroup.uiuc.edu:8080...2_2005d179.he5 and it's subject to change.


Identifying Plottable Datasets


When Panoply opens the remote MLS file, the plottable datasets will have [lat][vert] under Type column as shown below. If you don't see any plottable dataset, your handler is out of date.



In the above picture, you see "A2" prefix on L2gpValue because the handler is compiled with --enable-short-path option.


Applying Log() on Small Values


This is the tricky part to get a nice graph for MLS datasets. If you see a boring picture like below, it's time to apply log function on Pressure.





First select Grid tab. Then, select Log10 of Value in Vert Axis Units. You'll get a nice cross section view of MLS data like below.




Adjust the Legend


Since the legend shows all 0.0 in the above picture, let's adjust it to show the tiny values.



Select Scale tab and select %.6E from Tick Label Format drop-down menu. You'll get the nice labels as shown below.





That's it!