Meteorological Influences Within the Context of Air Quality in Beijing

Abstract

Daily PM2.5 samples were collected continuously with two high-volume samplers at the ground of CUGB from 06/2010 until 06/2011. The site is very near to the instrumentation for long-term investigation of the inorganic composition of PM2.5 (DWD, KIT/IMG). The daily filter samples are analyzed for carbon fractions, organic compound speciation (HMGU, UR), inorganic (KIT/IMG) and isotopic composition. Gaseous pollutants like NO, NO2 and O3 and compounds which are of interest for secondary aerosol formation like SO2 were measured by a DOAS with three retroreflectors from 04/2009 until 03/2011 in Beijing at LAPC. By path-integrated measurements at different directions information about emission sources (motorway, small street) can be provided. The emitter/receiver unit is in 20 m distance to an air pollution monitoring station. The diurnal development and variation of the mixing layer height (MLH) is determined by a ceilometer. It is shown that the variations of the observed SO2 and NO2 as well as PM2.5 concentrations are influenced by the MLH, apart from the meteorological (e.g. wind), emission (e.g. SO2) and photochemistry dependences. High air pollution is coupled significantly with MLH lower than 1,000 m.