Airborne measurements of gas and particle pollutants during CAREBeijing-2008

Abstract

Abstract. Measurements of gaseous pollutants -including ozone (O 3 ), sulfur dioxide (SO 2 ), nitrogen oxides (NO X = NO + NO 2 ), carbon monoxide (CO), particle number concentrations (5.6-560 nm and 0.47-30 µm) -and meteorological parameters (T , RH, P ) were conducted during the Campaigns of Air Quality Research in Beijing and Surrounding Regions in 2008 (CAREBeijing-2008), from 27 August through 13 October 2008. The data from a total 18 flights (70 h flight time) from near the surface to 2100 m altitude were obtained with a Yun-12 aircraft in the southern surrounding areas of Beijing (38-40 • N, 114-118 • E). The objectives of these measurements were to characterize the regional variation of air pollution during and after the Olympics of 2008, determine the importance of air mass trajectories and to evaluate of other factors that influence the pollution characteristics. The results suggest that there are primarily four distinct sources that influenced the magnitude and properties of the pollutants in the measured region based on back-trajectory analysis: (1) southerly transport of air masses from regions with high pollutant emissions, (2) northerly and northeasterly transport of less pollutant air from further away, (3) easterly transport from maritime sources where emissions of gaseous pollutant are less than from the south but still high in particle concentrations, and (4) the transport of air that is a mixture from different regions; that is, the air at all altitudes measured by the aircraft was not all from the same sources. The relatively long-lived CO concentration is shown to be a possible transport tracer of long-range transport from the northwesterly direction, especially at the higher altitudes. Three factors that influenced the size distribution of particles -i.e., air mass transport direction, ground source emissions and meteorological influences -are also discussed.

Multi-model evaluation of short-lived pollutant distributions over east Asia during summer 2008

“…Three flight routes covering the area 38-40 • N and 114-118 • E from Tianjin to Shijiazhuang were flown repeatedly. Zhang et al (2014) showed that the flights sampling polluted air masses originated from urban areas south of the flight locations and suggested a limited influence from emission mitigation measures applied in the Beijing municipality at this time. Observed ozone precursors are elevated up to about 1.5 km, showing that the entire boundary layer was influenced by pollution.…”

“…Flights followed linear routes at altitudes in the range 500-2100 m in order to sample both the boundary layer and the free troposphere. The instrumentation on board the aircraft is described by Zhang et al (2014) and includes ozone, CO, SO 2 and NO x samplers. The flight tracks are shown in blue in Fig.…”

“…The ECLIPSE model evaluation over east Asia focuses on the summer period (August and September 2008). This was motivated by the availability of intensive observations from the CAREBEIJING 2008 measurements campaign (Huang et al, 2010;Zhang et al, 2014) and by the fact that severe ozone pollution episodes occur over NCP at this time of year even if the maximum is generally earlier in the late spring for trace gases (Naja and Akimoto, 2004;Li et al, 2007;He et al, 2008;Safieddine et al, 2013) and aerosols (Cao et al, 2004;Sun et al, 2004;Yang et al, 2005;Huang et al, 2006). During the summer months, the monsoon circulation brings cleaner air from the Pacific Ocean into southern and eastern Asia reducing pollutant concentrations (Lin et al, 2009;Kim et al, 2007).…”

Airborne Measurements of High Pollutant Concentration Events in the Free Troposphere over the West Coast of South Korea between 1997 and 2011

“…Secondly, the concentration of specific components, such as SO 2 , CO, O 3 , NO x , etc. directly measured from the aircraft, facilitates quantitative analysis (e.g., Hatakeyama et al, 2004;Corrigan et al, 2008;Wang et al, 2008;Chen et al, 2013;Zhang et al, 2014). Airborne measurements allow to distinguish the FT air pollutants from those in the PBL, and in turn allow to identify the meteorological conditions related with the occurrence of high-concentration events in the troposphere.…”

Distribution and sources of air pollutants in the North China Plain based on on-road mobile measurements

“…A number of mobile laboratory measurements (Johansson et al, 2008;Li et al, 2009;Wang et al, 2009Wang et al, , 2011 and aircraft measurements (Huang et al, 2010;Zhang et al, 2011Zhang et al, , 2009Zhang et al, , 2014 have been used to determine pollution distributions, mainly within the megacity of Beijing. There have been several reports of model and satellite studies on the air pollution distribution in the NCP, or even the whole of China (Wei et al, 2011;Zhao et al, 2013;Ying et al, 2014;Ding et al, 2015Ding et al, , 2009).…”