Ventilation of pollutants from the Los Angeles Basin is suppressed by persistent temperature inversions. A consulting firm proposes to fix this problem by installing large burners throughout the Basin to heat the air and break the inversion. a) Explain theoretically how this would work (briefly).
b) Consider a typical inversion layer over the Basin extending from 500 to 1000 m altitude, with temperatures increasing linearly from 288 K (at 500 m) to 293 K (at 1000 m). Assume that the lapse rate of the atmosphere is equal to the dry adiabatic lapse rate below 500 m and above 1000 m. Calculate the energy required to destroy the inversion over the area of the Los Angeles Basin (4000 km²). Assume that Pair = 1 kg m-3 and Cp = 1x10 J kg ? K for air.
c) The energy produced by burning oil in a power plant is 1.2x10'J (Kg oil)?. Calculate the amount of oil which needs to be burned to break the inversion.
d) Assume that the oil is 80% carbon by weight, and that all the carbon burned is transformed into CO2. Calculate the average ppm increase in CO2 concentration that would occur in Los Angeles Air before the inversion was broken. Conclude as to the practicality of the proposal.
e) On some days the sun will eventually heat the air enough to ventilate the Los Angeles Air Basin. Assume the solar heat flux W to the surface is given by:
W = Wo cos (21 (t-12)/24) from t= 6 to 18
Wo = 500 W m2
t = local time in hours
Starting from to = 6 a. m., the sun begins to heat the surface (solar heat flux increases from sunrise until noon, then decreases until sundown). What time is the Basin finally ventilated (assume the same starting temperature profile outlined in b).