A stack emitting 80 g/s of NO has an effective stack height of 100 m. The wind speed is 4 m/s at 10 m, it is located in an urban area, and it is a clear summer day with the sun nearly overhead. Estimate the ground level NO concentration
a) Directly downwind at a distance of 2 km.
b) At the point downwind where NO is a maximum.
c) At a point located 2 km downwind and 0.1 km off the downwind axis