Reading data from one grid and adding the value of a cell to another grid

VERDI
1

Hi,
I’m running CMAQ on two different grids, one coarse and one fine within the former one, but these are not nested and come from two different sets of simulations (one with wind blown dust and one without).
I wonder if I can evaluate the value of one variable at a specific cell of the coarse grid and add it to the data of all cells in the fine grid inside VERDI, by some kind of formula?
To be more specific (in VERDI environment), can I write a formula based on the value of a specific cell (or a probe)?
I think it’s quite doable outside VERDI, but I prefer to do it in VERDI, as it makes things much easier for me.
By the way, I’m working on VERDI 2.1.3.
Thanks.

2

Outside VERDI, this is a simple application of M3Tools programs m3cple followed by m3diff …

3

@cjcoats
Thanks for quick reply.
Although I’m still waiting for a response on the VERDI side, I went through your recommendations, and so far so good! It seems that it does what I want without much effort.
I appreciate, if you can direct me to somewhere to learn for the following part you’ve written on the manuals:
" If you want to run this program in batch mode (from a script) …"
Any working example is much appreciated.

Cheers,

4

The m3diff page does have an example of how to script the program for batch-operation. Looking at that, and an interactive run of m3cple, you should be able to figure out how to run it from a script as well.

5

I wrote a small piece of script for running the m3cple from terminal, that does what I wanted. For the others, with little modification, it should work.

#!/bin/tcsh -f

    setenv infile COMBINE_ACONC_2024-03-07-wbd.nc    #it's present in the directory of this script or use the exact address
    setenv GRIDDESC GRIDDESC   #it's present in the directory of this script or use the exact address
    setenv outfile out-batch.nc  # it's generated in the current directory
    
    set cmd=batch-m3cple
    
    echo "Y" 		   >& $cmd
    echo "NONE"        >> $cmd
    echo "infile"      >> $cmd
    echo "CMAQ1"       >> $cmd    # grid name in the gridesc file.
    echo ""            >> $cmd    #  default 
    echo ""            >> $cmd    #  default 
    echo ""            >> $cmd    #  default 
    echo ""            >> $cmd    #  default 
    echo "$outfile"	   >> $cmd
    
    ./m3cple < $cmd     #m3cple is linked from the BIN directory of IO-API package to the current directory
2 Likes
6

It is currently not possible to do a comparison of two different gridded datasets (finer grid versus coarser grid) within VERDI.