HAZMAT Materials for Dispersion

[GHarveyOEM]

Hi, all. I am currently working on a project that involves both ALOHA and HYSPLIT for HAZMAT situations. ALOHA is a great tool, however some of its limitations could cause an issue if there was a large-scale incident beyond the scope of ALOHA. On top of 1-hour limit and a 10-mile radius. (IIRC)

I also understand HYSPLIT has an option for "unknown material" but what I'm trying to figure out is whether I can run HYSPLIT with a little more specificity, much like ALOHA.  The two most likely/important chemicals are anhydrous ammonia (molecular weight = 17.03) and chlorine (molecular weight = 70.91). If that's not the case, what would be best to use outside of ALOHA, and a feature that I can use in HYSPLIT to determine the location with potential ppm concentration? In addition, what meteorological parameters and model would be best to use for determining where the hazardous plume will travel? I was thinking HRRR model given it's short-term; but is there something better?

I have tried using both dispersion and trajectory models but need to narrow the options down and try to get the best outcome possible in the event of an incident.

Thanks!

[sonny.zinn]

Online HYSPLIT for registered users (at https://www.ready.noaa.gov/HYSPLIT_disp.php) supports the modeling of chemical dispersion and produces plume concentrations in parts per million (ppm). Both the NAM CONUS Nest (CNEST) and HRRR provide meteorological data at 3 km resolution. HRRR is updated every hour, whereas NAM CNEST is updated every six hours. HRRR should therefore be the first choice, followed by NAM CNEST.

[GHarveyOEM]

Excellent. Thank you.

Will experiment and see if this can be used for application purposes.

GH