HYSPLIT Forum: hysplitbbs.arl.noaa.gov

Say I am using the EMITIMES file and define a system with a duration of an hour at 100 kg/hr at a certain height. In terms of total mass emitted, what is the difference between setting the area as 1000m^2 or as a point source with 0 m^2. I would think that the total mass is the same in each case but just spread out since it is not defined as a flux quantity but an emissions rate (not kg/(hr *m^2) but kg/hr). Is this how it is calculated?

Also to regain the total mass after a simulation I was thinking of defining a level that is above the highest particle and taking the average in that grid and multiplying it by the grid area and the height of the level. Is this the best way to do this?

When you define an area in the emission file, at the time of the emission, your lagrangian particles will be horizontally distributed over that area. The mass is always the same.

You can certainly calculate the total mass using the approach you described but your results will depend on the height of the layer that you define.
I would suggest you define several vertical layers and then run concplot using option e4, which calculates the mass loading for you.

So how does this work with the CMASS option set to 1? Would the output be the average in that height interval (with units of mass/m) or would it just get the mass in that interval?

In that case the units should be mass*m