3.4.2 How environmental features affect the severity of pollution Flashcards
what is the most recognisable source of atmospheric pollution?
the industrial chimney or ‘stack’
How do industrial chimneys disperse pollutants?
exhaust gases and pollutants leave a stack, they mix with air creating a PLUME
Plume travels downwind and its diameter grows progressively spreading the pollutant
After the initial stage what is the dispersal of pollutants in the atmosphere a result of?
velocity and direction of airflow
stability of the atmosphere
What affects the composition of the atmosphere?
altitude
What is the most significant layer of the atmosphere that we interact with?
the TROPOSPHERE
what happens with temperatures with increasing altitude in the troposphere?
temperatures typically decline
What can show the relationship between altitude and temperature in the troposphere?
Lapse rate diagram
How do effluents rise through the atmosphere?
they cool as they rise but as long as they are warmer than the surrounding air they will be buoyant enough to continue rising and be widely dispersed
What can cause the air nearer the ground to be cooler than the air above?
solar heating of the lack thereof the suns heat energy reaching the surface
what are the characteristics of cooler air?
more dense and less buoyant so any pollutants released cannot disperse easily and become more concentrated
What is temperature inversion?
when cold air that is close to the ground and that is more dense traps any pollutants released cannot disperse easily and become more concentrated
where can temperature inversion occur?
in a valley
low wind velocity
cloudless skies
mist or fog
why does temperature inversion occur in valleys?
because cool dense air can collect in the valley especially those with steep sides and little sunlight yo warm the air within them close to the ground
How can low wind velocity cause temperature inversion?
stops the air layers with different temperatures from mixing as cold air is denser it sinks and does not mix with the warm air
How can cloudless skies cause temperature inversion?
when there are no clouds the terrestrial infrared radiation is radiated up from the ground and released into the air above the lack of clouds allows radiation to reach high altitudes
