LR-x® and ALOHA

Short answer

ALOHA is the dispersion (plume) model in the EPA/NOAA CAMEO suite. LR-x® takes ALOHA's many input fields and puts them into a streamlined mobile app, adds a 3D wind field model over terrain, runs forecast models from forecast weather, and archives every live and what-if run automatically.

Desktop ALOHA compared with LR-x

	Desktop ALOHA installation	LR-x®
Where it runs	A computer you maintain and update	Cloud, viewed on iOS, Android or a browser
Data entry	Many input fields	Address search or map pin, drop-down chemical list, auto-populated minimum fields
Chemicals	ALOHA chemical library: 500+ pure chemicals and some common solutions	Any chemical ALOHA can model, including H2S and chlorine
Weather	Entered or connected by the user	Nearest public weather station pulled automatically; on-scene WEATHERPAK® sensor supported
Wind	One wind speed and direction, flat ground	The same ALOHA run, shown with an ARL 3D wind field over terrain (5 m and 50 m)
GIS	Export from the desktop app	KML export of real-time plume, 3D wind field and forecast models for ArcGIS
Forecasts	Separate runs	Three forecast models, one about every 2 minutes
Sharing	Export and send	Share link; viewers need no account or app
Records	Saved files	Model History for after-action reports

Do I still need to maintain ALOHA?

No. ALOHA is fully maintained in the cloud for you. CAMEO Chemicals and MARPLOT are part of the same workflow.

Which chemicals can LR-x® model?

Any chemical ALOHA can model. According to NOAA, ALOHA's chemical library holds over 500 pure chemicals and some common chemical solutions, a subset of the CAMEO Chemicals database, and ALOHA uses a Gaussian model for neutrally buoyant gases and a Heavy Gas model for dense gases. That includes hydrogen sulfide and chlorine. (NOAA ALOHA Technical Documentation)

What does ALOHA output look like in LR-x®?

The plume is drawn as red, orange and yellow threat zones (AEGL levels in parts per million) over Google Maps, satellite imagery or terrain. Tap any part of the zone to read its details. See the assess step, or read how the 3D wind field model handles terrain.