The Britter-McQuaid plume model allows for wind speeds of zero.

The Britter-McQuaid plume model allows for wind speeds of zero.

• A. True
• B. False
• C. Not specified
• D. Both

Answer: (B)

The Britter-McQuaid plume model relies on the plume being advected by a steady, nonzero wind. In the model’s formulation, wind speed appears in the scaling of the downwind concentration; the solution effectively uses advection to transport the plume and dilution by dispersion. If the wind were zero, there would be no advection to carry the plume downwind, and the mathematical form of the model would become undefined or physically inappropriate for a downwind receptor—the concentration would not reach receptors in the first place under the model’s steady-state assumptions. In practice, near-zero winds are handled by using a small wind speed floor or by switching to a different, time-dependent diffusion-dominated approach, but the Britter-McQuaid model itself is not defined for zero wind. Therefore, the statement is not correct.

The Britter-McQuaid plume model relies on the plume being advected by a steady, nonzero wind. In the model’s formulation, wind speed appears in the scaling of the downwind concentration; the solution effectively uses advection to transport the plume and dilution by dispersion. If the wind were zero, there would be no advection to carry the plume downwind, and the mathematical form of the model would become undefined or physically inappropriate for a downwind receptor—the concentration would not reach receptors in the first place under the model’s steady-state assumptions. In practice, near-zero winds are handled by using a small wind speed floor or by switching to a different, time-dependent diffusion-dominated approach, but the Britter-McQuaid model itself is not defined for zero wind. Therefore, the statement is not correct.