Efficiency of cloud condensation nuclei formation from ultrafine particles

• DOI: 10.5194/acp-7-1367-2007
• Publication Date: 2010-04-29T13:52:44Z
• Authors: J. R. Pierce; P. J. Adams
• Keywords: Cloud condensation nuclei; Ultrafine particle; Sink (geography)

Abstract. Atmospheric cloud condensation nuclei (CCN) concentrations are a key uncertainty in the assessment of effect anthropogenic aerosol on clouds and climate. The ability new ultrafine particles to grow become CCN varies throughout atmosphere must be understood order understand formation. We have developed Probability Ultrafine particle Growth (PUG) model answer questions regarding which growth sink mechanisms control this growth, how between different parts uncertainties with respect magnitude size distribution emissions translates into generation. inputs PUG condensable gases, ambient aerosol, deposition timescales physical properties gases. It was found most cases that is dominant mechanism coagulation larger for particles. In work we probability generating from <0.1% ~90% atmosphere, though boundary layer large fraction 1% 40%. Some regions, such as tropical free troposphere, areas high probabilities; however, variability within regions makes it difficult predict efficient For given mass primary an factor two modal diameter can lead number generated eight. no single moment distribution, total or number, robust predictor ultimately generated. Therefore, complete description generally required global microphysics models.