FAQs Plume Rise Parameters

The defaults for Plume Top Height (in meters) are generated from the FEPS model based on calculated heat release over time (which is calculated by CONSUME). It’s shown on the timeseries graphic using the local time zone of the fire.

It is not a requirement to adjust the plume top height. The Plume Top generated by the model given heat release is a practical assumption.

Now, this Plume top can be adjusted as a percentage of the calculated plume, based on the user’s preference and/or knowledge. An unstable atmosphere could potentially increase your plume height. A stable atmosphere could potentially decrease your plume height.

The defaults are to have a well-mixed profile so that emissions are distributed evenly on the vertical. If the user has information about stability and expects conditions to be different, i.e., more stable (more emissions closer to the ground) or more unstable (more emissions being lifted higher), then the user has the chance to select those other options.

Playground does not use this information from the Met file.

CONSUME calculates consumption by combustion phase and produces the total emissions per hour.

The Fraction of Emissions Emitted at Ground Level is used to specify the percentage of the total emissions that will be allocated near the ground instead of letting the model decide that. Users could use this in situations with a more stable atmosphere or under other conditions where wouldn’t expect emissions to be well mixed or lifted high.