CLOUD NUCLEUS FORMATION IN A POWER-PLANT PLUME

A rate of production of ca 1016 particles s-1 of H2SO4 aerosol that acts as cloud condensation nuclei at 1% supersaturation has been estimated to take place in the emission plume from the Four Comers power plant near Farmington, N.M. This generating plant produces about 2175MW at full capacity and emits about 3.7kgs-1 of SO2, 2.2 kgs-1 of NOx, and 0.9 kgs-1 of particulates. The site area is desert; annual precipitation averages around 15cm, daytime relative humidity is typically 10-20% and annual sunshine is 75% of possible. An instrumented aircraft was utilized during five investigative periods over a 2-year span to measure plume parameters and to collect plume aerosol samples. The estimated production rate of 1016 particles s-1 in the plume is equivalent to a gas phase oxidation of SO2 and homogeneous nucleation-condensation of about 5 μg m-3h-1 of H2SO4 and is consistent with this mechanism being the primary route for removal of SO2. © 1978.