AQS Air Dispersion Modeling 2

Question 1

The Pasquill-Gifford atmospheric stability classes are primarily determined by which two parameters?

Accepted Answer

Surface wind speed and solar radiation (or cloudiness at night)

Answer

P-G stability classes are determined by surface wind speed combined with incoming solar radiation during daytime, or net cloudiness during nighttime.

Question 2

CALPUFF is most appropriate for which air dispersion modeling scenario?

Accepted Answer

Long-range transport (>50 km) or complex meteorological conditions with variable winds

Answer

CALPUFF is a non-steady-state Lagrangian puff model designed for long-range transport and conditions where steady-state plume assumptions are invalid due to variable winds.

Question 3

In air dispersion modeling, a 'receptor' is defined as:

Accepted Answer

A location (point or grid node) where predicted ambient concentrations are calculated

Answer

A receptor is a specified location—part of a receptor grid or discrete point—where the model computes predicted ambient pollutant concentrations.

Question 4

Which stack parameter has the greatest influence on buoyancy-induced plume rise in a Gaussian dispersion model?

Accepted Answer

Exit gas temperature relative to ambient air temperature

Answer

Buoyancy rise is driven primarily by the temperature difference between the hot exhaust gas and cooler ambient air, as this determines the density contrast that provides lift.

Question 5

In AERMOD, which source type is most appropriate for modeling fugitive emissions from a large storage pile or parking lot?

Accepted Answer

AREA source

Answer

Area sources in AERMOD represent diffuse emissions distributed over a surface area, making them appropriate for storage piles, parking lots, and land application sites.

(AQS) Air Quality Specialist Certification Practice Test

(AQS) Air Quality Specialist Certification Practice Test

AQS Air Dispersion Modeling 2