Significant contributions of trimethylamine to sulfuric acid nucleation in polluted environments

Abstract As one of the least understood aerosol processes, nucleation can be a dominant source atmospheric aerosols. Sulfuric acid (SA)-amine binary with dimethylamine (DMA) has been recognized as governing mechanism in polluted continental boundary layer. Here we demonstrate importance trimethylamine (TMA) for complex atmosphere and propose molecular-level SA-DMA-TMA ternary an improvement upon conventional mechanism. Using proposed mechanism, could connect gaseous amines to SA-amine cluster signals measured urban Beijing. Results show that TMA accelerate SA-DMA-based new particle formation Beijing by 50–100%. Considering global abundance DMA, our findings imply comparable DMA layer, probably higher contributions from rural environments future controlled emissions.