L W SPM In the well mixed urban airshed shown at right, there is an area particulate matter (PM) emission source (Spm) and a sink due to settling (settling velocity vs). The wind velocity is u; there is no PM in the air coming into the urban area. U- W=L= 20 km H= 1 km u= 1 km/hr SPM = 5 kg/km/hr Vs = 0.05 km/hr H a)Write the steady state mass balance equation, then solve for PM concentration. b) Downwind of the airshed in part there is no source emission (Spm=0) but still chemical reactions occurring. These chemical reactions are converting SO2, a gas, to sulfate (SO4) particulate matter (PM). The SO2 level leaving the city is 10 ppbV (~27 ug m), and reacts at the rate of 2%/hr. Modeling the air as it moves downwind as a plug flow system, write the PM mass balance equation, then solve for the PM concentration 5 hrs downwind. The PM still settles during transport. L W SPM In the well mixed urban airshed shown at right, there is an area particulate matter (PM) emission source (Spm) and a sink due to settling (settling velocity vs). The wind velocity is u; there is no PM in the air coming into the urban area. U- W=L= 20 km H= 1 km u= 1 km/hr SPM = 5 kg/km/hr Vs = 0.05 km/hr H a)Write the steady state mass balance equation, then solve for PM concentration. b) Downwind of the airshed in part there is no source emission (Spm=0) but still chemical reactions occurring. These chemical reactions are converting SO2, a gas, to sulfate (SO4) particulate matter (PM). The SO2 level leaving the city is 10 ppbV (~27 ug m), and reacts at the rate of 2%/hr. Modeling the air as it moves downwind as a plug flow system, write the PM mass balance equation, then solve for the PM concentration 5 hrs downwind. The PM still settles during transport