Impact of meteorological parameters on the concentrations of organic acids in precipitation

Organic acids are important and ubiquitous constituent in atmosphere.The levels of organic acids in precipitation in Guiyang city were determined with ICS-90 Ion Chromatography.The results show that meteorological parameters have important impacts on the concentration levels of organic acids in precipitation.During the wet precipitation events,the rain fluxes of organic acids generally decreased as a function of time and the scavenging of atmospheric organic acids by wet precipitation mostly take place during the early stage of the precipitation.Thunderstorm and typhoon rain were determined with lower organic acids concentrations,and the concentration levels of organic acids in snow were much lower than those in precipitation which indicate atmosphere organic acids were mainly incorporated into the precipitation during the below-cloud process.Weather parameters such as temperature have little effect on the organic acid concentrations compared to rainfall amount.The air-mass back-trajectory analysis indicated that precipitation with inland back-trajectory coming from the north had the highest concentrations of organic acids while the marine back-trajectory coming from the southeast had the lowest concentrations.