Smoke Management & Air Quality Flashcards

What meteorological condition is most favorable for smoke dispersal during a prescribed burn?

Answer: High mixing height with strong transport winds aloft

A high mixing height combined with good transport winds allows smoke to disperse both vertically and horizontally, reducing ground-level concentrations.

What is a temperature inversion in the context of prescribed fire smoke management?

Answer: A layer of warm air above cooler air that traps smoke near the ground

A temperature inversion traps smoke near the ground because the overlying warm air layer prevents upward mixing, creating hazardous air quality conditions.

Which pollutant from prescribed fire smoke is the primary concern for human health?

Answer: Fine particulate matter (PM2.5)

PM2.5 particles are small enough to penetrate deep into the lungs and are the primary health concern from wildfire and prescribed fire smoke.

What does 'mixing height' refer to in smoke management?

Answer: The altitude to which convective mixing extends in the atmosphere

Mixing height is the altitude to which the atmosphere is well-mixed due to convective activity, determining how high smoke can rise and disperse.

Which prescribed burn technique typically produces the most smoke per acre due to slower, more smoldering combustion?

Answer: Backfire (burning against the wind)

Backfires burn more slowly and involve more smoldering combustion, generating more smoke per unit of fuel consumed compared to fast-moving headfires.

What is the Ventilation Index (VI) used to estimate in smoke management?

Answer: The atmosphere's capacity to dilute and transport smoke away from a burn

The Ventilation Index combines mixing height and transport wind speed to estimate the atmosphere's capacity to disperse smoke away from a burn area.

What time of day is generally LEAST suitable for igniting a prescribed burn due to smoke management concerns?

Answer: Early morning before the atmospheric mixing layer has developed

Early morning burning is problematic because nocturnal temperature inversions are strongest at that time, trapping smoke near the ground before the mixing layer develops.