Briggs plume rise estimation is used to estimate which quantity in the plume-height calculation?

Briggs plume rise estimation is used to estimate which quantity in the plume-height calculation?

• A. The wind speed u
• B. The vertical rise Δh due to buoyancy and momentum
• C. The receptor height z
• D. The ground reflection term

Answer: (B)

This item tests how the plume-height calculation accounts for the vertical rise of the plume as it leaves the stack. Briggs plume rise estimation provides the vertical rise Δh due to buoyancy and momentum, and this rise is added to the physical stack height to set the effective release height used in the Gaussian plume model. That makes Δh the quantity being estimated, because it directly determines how high the plume effectively starts dispersing from. The other elements—wind speed, receptor height, and ground reflection—play different roles in the overall dispersion calculation but are not what Briggs directly provides as the rise term.

This item tests how the plume-height calculation accounts for the vertical rise of the plume as it leaves the stack. Briggs plume rise estimation provides the vertical rise Δh due to buoyancy and momentum, and this rise is added to the physical stack height to set the effective release height used in the Gaussian plume model. That makes Δh the quantity being estimated, because it directly determines how high the plume effectively starts dispersing from. The other elements—wind speed, receptor height, and ground reflection—play different roles in the overall dispersion calculation but are not what Briggs directly provides as the rise term.