Evolution under dark conditions of particles from old and modern diesel vehicles in a new environmental chamber characterized with fresh exhaust emissions

Abstract. Atmospheric particles have several impacts on health and the environment, especially in urban areas. Parts of those are not fresh undergone atmospheric chemical physical processes. Due to a lack representativeness experimental conditions artifacts such as particle wall losses chambers, there uncertainties effects processes (condensation, nucleation coagulation) their role evolution from modern vehicles. This study develops new method correct losses, accounting for size dependence experiment-to-experiment variations. It is applied diesel exhaust characterize which they undergo. The correction based black carbon decay size-dependent coefficient distributions. Six passenger cars, Euro 3 6, were driven chassis dynamometer with Artemis Urban cold start Motorway cycles. Exhaust was injected an 8 m3 chamber Teflon walls. characterized during 6 10 h. Increase mass observed even without photochemical reactions due presence intermediate-volatility organic compounds semi-volatile compounds. These quantified at emission induce increase up 17 % h−1, mainly older vehicles (Euro 4). Condensation 4 times faster when available surface multiplied by 6.5. If initial number concentration below [8–9] × 104 cm−3, mode seems be present but measured scanning mobility sizer (SMPS). growth nucleation-mode results [PN]. Above this threshold, decreases coagulation, −27 h−1. Under conditions, setup well suited characterizing quantifying process coagulation.