Urban air pollution abatement - I. Using a one-compartment model (CSTR), estimate the air residence time for the following situations: Urban area Land area (km2) Los Angeles, CA 4,000 Minneapolis, MN 2,000 Ames, IA 50 Use a wind speed of 3 m/s and a mixing height of 400 m, and assume that the urban area is a square shape (length = width). Based on your calculations, if there is a sudden change in emissions (say, if an environmental policy reduces emissions), how long would it take for the impact on concentrations to take effect