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

Ambient temperature and relative humidity

Answer

Stack exit velocity and exhaust temperature

Answer

Terrain slope and receptor distance

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

Single point source in flat terrain within 5 km of receptors

Answer

Modeling indoor air concentrations from infiltration

Answer

Short-term acute releases lasting less than one hour

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

The facility emitting pollutants being modeled

Answer

The meteorological monitoring station providing input data

Answer

The regulatory concentration threshold being compared against

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

Physical stack diameter

Answer

Physical stack height

Answer

Stack exit velocity

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

POINT source

Answer

LINE source

Answer

VOLUME source

Question 6

In air dispersion meteorology, 'fumigation' refers to which phenomenon?

Accepted Answer

Rapid downward mixing of an elevated plume to ground level during morning breakup of a nocturnal temperature inversion

Answer

Deliberate injection of tracer gases to measure atmospheric dispersion

Answer

Chemical scrubbing of pollutants within the plume by ambient moisture

Answer

Wet deposition of pollutants by rainfall intercepting the plume

Question 7

The mixing height (mixing layer height) is important in air dispersion modeling because it:

Accepted Answer

Defines the upper boundary of the well-mixed layer, limiting vertical dispersion of pollutants

Answer

Determines the minimum required stack height for permit compliance

Answer

Controls the horizontal wind direction used in plume trajectory calculations

Answer

Sets the receptor grid spacing required for regulatory modeling