A point source with effective stack height of 50 m emits 80 g/s of on a clear summer day with surface winds at 4 m/s. Winds at 50 m are 5 m/s. An inversion layer starts at an elevation of 250 m.
(a) Estimate the ground- level concentration at a distance of 4 km downwind from the stack.
(b) If there had been no inversion layer, estimate the concentration 4 km downwind.