Hi,

I was wondering how I can aggregate and re-project my ioapi netcdf emission files? I would appreciate any possible solutions.

I tried using INSERTGRID from IOAPI m3tools to make it happen, and I am facing the following error: forrtl: severe (154): array index out of bounds

I am not sure what exactly is happening.

Also I would appreciate sharing any experience with this tool.

Thanks,

Kiarash

First, note that emissions files are generally have an (implicit) **per grid cell** component of their actual physical units. This means that re-gridding algorithms must also apply the ratio (â€ś*gridding ratio*â€ť) of the output grid cell area to the input grid cell area.

If this ratio `*(output grid-cell area)/(input grid-cell area)*`

is much less than 1.0, then interpolation is appropriate: you want to use M3Tools program**m3cple** for that. The latest version of this program has a scale-factor option that you can use to re-scale by the correct gridding ratio; for earlier versions, you will need to re-scale afterwards using (a trivial application of) M3Tools program**m3combo**

Otherwise (if the output grid is as coarse as, or coarser than) the input grid, you need to do a more sophisticated area-sampling procedure. M3Tools program **mtxcple** does that, using transform matrices calculated by **mtxcalc** using a sub-sampling algorithm.

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Thank you for your provided information.