Aerosol mass spectrometer constraint on the global secondary organic aerosol budget

摘要: Abstract. The budget of atmospheric secondary organic aerosol (SOA) is very uncertain, with recent estimates suggesting a global source between 12 and 1820 Tg a−1. We used dataset mass spectrometer (AMS) observations from 34 different surface locations to evaluate the GLOMAP chemical transport model. standard model simulation (which included SOA monoterpenes only) underpredicted (OA) observed by AMS had little skill reproducing variability in dataset. simulated formation biogenic (monoterpenes isoprene), lumped anthropogenic biomass burning volatile compounds (VOCs) varied yield each precursor produce best overall match observations. assumed that essentially non-volatile condenses irreversibly onto existing aerosol. Our estimate 140 a−1 but large uncertainty range which we be 50–380 found minimum normalised mean error (NME) when (100 a−1) sources spatially matched pollution term antropogenically controlled SOA). carbon compiled Bahadur et al. (2009) our estimated sources. was most consistent these observations, however improvement over (250 small. 14C rural maximum 10 (10 %) anthropogenically could fossil (urban/industrial) suggest an additional likely due enhancement VOCs. Such would result substantial climate forcing. direct effect −0.26 ± 0.15 Wm−2 indirect (cloud albedo) −0.6+0.24−0.14 SOA. are not well constrained this analysis limited number OA regions periods strongly impacted To further improve constraints method, needed tropics Southern Hemisphere.