The influence of organic compounds on the development of precipitation acidity in maritime clouds
[摘要] In order to estimate the anthropogenic influence of gas and aerosolemissions from the Petroleum Industry in maritime zones with clouds of smallvertical extent, a numerical 1-D Eulerian cloud-chemical model with detailedmicrophysics (Alfonso and Raga, 2002) is used to simulate the influence ofwater soluble organic compounds (WSOC) and organic+inorganic gas emissionson cloud development. Following Mircea et al. (2002), we tested thesensitivity of the cloud and precipitation development in the classicalinorganic case (CIC) and the inorganic+organic case (IOC) with respect toCCN compositions. The results indicate an increase in the dropletconcentration for the IOC, and a delay in the development of precipitation.
The pH spectral evolution was studied during both the development andprecipitation stages. The influence of the diffusion of formic acid and itsgeneration by oxidation of hydrated formaldehyde in the aqueous phase resultin a reduction in the pH of precipitation in the range between 0.05 and 0.15 pHunits (from 1 to 3%) for the high ambient SO2 concentration (20ppb) and between 0.2-0.5 pH units (from 4 to 10%) for the low ambientSO2 concentration (1 ppb) case.
