Topic 4: Air Pollution Meteorology

Question 1

What is air pollution?

Answer 1

aerosols or particles in the air from anthropogenic (combustion) or natural sources (bushfires, dust storms)

Question 2

What are the two main natural sources of pollution?

Answer 2

Dust storms and volcanic eruptions (source of S)2, bad for aviation, ash accumulation and water contamination)

Question 3

What is the aviation ash model?

Answer 3

A model used to predict the presence of ash in the atmosphere which may make it dangerous for a plane to fly

Question 4

What effect does the emission of particulate matter have on humans? sources of emission?

Answer 4

health: aggravate respiratory problems, decrease lung function, visibility reduction and can act as CCN’s Sources: motor vehicles, burning, bushfires, volcanoes

Question 5

What effect does sulphur dioxide have as a pollutant?

Answer 5

if in the stratosphere can cause cooling for a few years, results in acid rain, irritates throat and lungs, can cause headaches etc

Question 6

What is the natural pH of rain?

Answer 6

5

Question 7

what effect does Carbon monoxide have as a pollutant?

Answer 7

source: cars and smoking, can be lethal if prolonged exposure occurs.

Question 8

what effect does Carbon dioxide have as a pollutant?

Answer 8

acts as a greenhouse gas

Question 9

what effect do oxides of nitrogen have as a pollutant?

Answer 9

creates photochemical smog that produces ozone at the surface

Question 10

What are the two concentration units used in air pollution?

Answer 10

(1) Mixing ratio approach - ppm (2) density approach/concentration - micrograms per cubic m concentration = ppm X (P Mi)/(R’T) R’ = 8.144 j/mol

Question 11

What are the three typical source configurations?

Answer 11

point, line and area

Question 12

What is the effect of meteorology on air pollution transport?

Answer 12

Transport by winds, diffusion by turbulence (mechanical and convection), sets limits to vertical motion (caps it in an inversion)

Question 13

What are the five basic plume patterns and their associated stability?

Answer 13

1. looping (strong instability, large eddies)
2. coning (windy neutral stability)
3. fanning ( strongly stable, thin vertically wide horizontally)
4. lofting (strongly stable below moderately unstable aloft - favoured)
5. Fumigation (inversion above, unstable below - least favoured)

Question 14

What is the role of wind speed dilution in pollution dispersion?

Answer 14

the greater the wind speed the lower the concentration for a unit distance

Question 15

What is the Gaussion plume model for point sources?

Answer 15

Concentration = source term x transport term x crosswind diffusion term x vertical diffusion term

Question 16

What is effective stack height?

Answer 16

the added height from buoyancy of the pollutant and wind speed

Question 17

This is the final form of the Gaussian plume model. what does each component represent?

Answer 17

Question 18

What are the five assumptions/limitations of the gaussian plume model?

Answer 18

1. continuous constant emission 2. flat terrain 3.no degrading reactions and pollutants are reflected when they hit the ground 4. wind speed is constant in time and elevation 5. concentration of pollutants have a normal distribution