Your residence is located one mile downwind and in a direct line from the two forbidding smoke stacks in the above photograph. Surely you will have some concentration of pollutants in the vicinity of your home. Now imagine the situation where everything is the same but the wind is blowing twice as hard. Do you think you will get a higher concentration of pollutants at your home or a lower concentration?

Observe the smoke plumes emitted from the two smoke stacks in the above photograph. Are the gasses emitted from these smoke stacks likely to be very hot?

In the above picture the sky seems overcast. Is the concentration of air pollution at your home likely to increase or decrease if the sun were to shine brightly and the clouds disperse?
 

The answers to these questions and many others are all taken into account in a mathematical model of air pollution calledThe Gaussian Plume Model. The Gaussian Plume Model provides a formula for the calculation of concentration of pollutants at any location downwind from the source of emission and at any given time after the emission started.
 

The table and graphs below represent typical concentration calculations and graphing for a simplified case of the plume model, the case of one dimensional diffusion. Both calculations and graphs were carried out with Microsoft Excel spreadsheet program.