Using a box model for the city, calculate the average steady-state concentration of pollutants if the average pollutant emissions from the city are 2×10^-5 g m-2 s-1 and the wind speed is 4 m s-1.

1) Consider an urban area (100 km^2) with a temperature profile that decreases linearly with height between 30 degrees C at the surface, and 24 degrees C at 500 m. At 500 m, the temperature increases with height to 30 degrees C at 1000 m.
What is the mixing height for this situation?
Using a box model for the city, calculate the average steady-state concentration of pollutants if the average pollutant emissions from the city are 2×10^-5 g m-2 s-1 and the wind speed is 4 m s-1.