VERDI does not react to CMAQ outputs

Hi, all;

I am trying to load a CMAQ output file “” which is about 2GB using VERDI 2.0 Beta. However VERDI does not react at all. No error message and no file loaded. I did adjust the memory cap to 6GB, so it should be fine. Is it caused by the netcdf format? Could you give me some suggestion?

Appreciate it!

Does VERDI have a RAM cap of 1024M? It seems my file is bigger than that.

Hi, Yijia,

You should be able to load your CMAQ file, which is in the IOAPI (quasi-netCDF) format. Unfortunately, there are times when VERDI doesn’t produce an error message.

VERDI does not have a RAM cap; it is only limited by the available physical memory in your computer. Just specify the -Xmx parameter in the VERDI run script to a value less than your available physical memory. You can definitely load model output files much larger than the -Xmx memory limit. The memory limit only becomes a factor once you start adding variables into Formulas for plotting; so after adding several 3-D variables, for example, you may need to limit either the Time Range or Layer Range or both.

Can you load any other CMAQ files, like those under ./data/model included with the VERDI distribution? A few more details on your CMAQ file and your computer system might be helpful.



Thanks for getting back to me!

Yes, I can certainly load the files in /data/model. There is no problem.

My CMAQ outputs are results from running CMAQ domain 12US1 for 3 days with a new ammonia inventory. Each .nc output is for one single day.

I am not sure if I need post-process the outputs by the embedded tools like combine? I don’t think I need to do any processing if I just simply want to visualize it in VERDI though. It is kind of frustrating because it took a lot of time to get it run but I eventually could not open the output…


Hi, Jerry;

I think I figured it out. I used m3tshift to filtrate the output without changing dates or time. Simply, I just input the original .nc file into the program m3tshift and output the same file. Now VERDI can load and read this output.