Many towns in the United States once operated open dumps; when refuse piled up too deeply, it was set on fire. A dump fire could burn for days, adding an eerie glow to the nighttime landscape. Assume that a certain dump fire emits 10 g/sec of soot particles (less than 0.1 mm in diameter). The mayor asks you to predict soot concentrations at city hall, 2 km directly downwind of the dump, during a planned outdoor ceremony. Model soot transport using the Pasquill-Gifford approach, treating the dump as a zero-height stack. a. If wind speed is 4 m/sec and it is a bright sunny day with a high mixing height, what is your prediction for soot concentration at ground level?

b. What would be your prediction for an overcast night with the same wind speed and mixing height?