Characteristics and sources of water-soluble organic aerosol in a heavily polluted environment in Northern China

Water-soluble organic aerosol (WSOA) in fine particles (PM2.5) collected during wintertime a polluted city (Handan) Northern China was characterized using High-Resolution Time-of-Flight Aerosol Mass Spectrometer (AMS). Through comparing with real-time measurements from collocated Chemical Speciation Monitor (ACSM), we determined that WSOA on average accounts for 29% of total (OA) mass and correlates tightly secondary (SOA; Pearson's r = 0.95). The spectra closely resemble those ambient SOA, but also show obvious influences coal combustion biomass burning. Positive matrix factorization (PMF) analysis the resolved water-soluble OA (WS-CCOA; O/C 0.17), burning (WS-BBOA; 0.32), oxygenated (WS-OOA; 0.89), which account 10.3%, 29.3% 60.4% mass, respectively. water-solubility factors estimated by offline AMS results ACSM measurements. OOA has highest 49%, consistent increased hygroscopicity oxidized organics induced atmospheric aging processes. In contrast, CCOA is least water soluble, containing 17% WS-CCOA. distinct characteristics different sources extend our knowledge complex chemistry atmosphere may help us to understand better its effects radiative forcing this region.