Quantification of total emission of air pollutants from Beijing using mobile mini-DOAS

This paper presents a novel method for quantification of the total emission of gases from area sources using the mobile mini-DOAS (Differential Optical Absorption Spectroscopy) instrument, a ground based optical remote sensing technique. The presented method has been applied to measure the emission of SO2 and NO2 from the city of Beijing, P.R. China, on a time scale of approximately 2 h. The measurements have been performed during two field campaigns, in April and in August 2005. The estimated emission of NO2 is roughly the same during the two field campaigns with an average emission of 189 tons d−1 during April and 174 tons d−1 during August. The estimated emission of SO2 varies greatly between the two periods, with an average emission of 293 tons d−1 during April and 52 tons d−1 during August.