Abstract:

Accurately representing the sources of important precursor gases for new particle formation and their chemical reactions in the atmosphere are critical for developing a robust understanding of the impacts of ultrafine particles on climate and health. Many types of compounds contribute to these nucleation and growth processes, including inorganic acids, bases and low-volatility organics. Both formation of these compounds in the atmosphere and the processes by which they are converted to ultrafine particles depend greatly on their composition. Therefore, these sources and processes were investigated using chemical ionization mass spectrometry to measure the chemical composition of important precursor gases generated in controlled laboratory chamber studies for three separate systems: vehicle brake-wear, nitrate radical-induced oxidation of four monoterpenes, and α-thujene ozonolysis.