Evaluation of regional background particulate matter concentration based on vertical distribution characteristics

Abstract

Abstract. Heavy regional particulate matter (PM) pollution in China has resulted in an important and urgent need for joint control actions among cities. It is advisable to improve the understanding of the regional background concentration of PM for the development of efficient and effective joint control policies. With the increase of height the influence of source emission on local air quality decreases with altitude, but the characteristics of regional pollution gradually become obvious. A method to estimate regional background PM concentration is proposed in this paper, based on the vertical characteristics of periodic variation in the atmospheric boundary layer structure and particle mass concentration, as well as the vertical distribution of particle size, chemical composition and pollution source apportionment. According to the method, the averaged regional background PM2.5 concentration in July, August and September 2009, being extracted from the original time series in Tianjin, was 40 ± 20, 64 ± 17 and 53 ± 11 μg m−3, respectively.

Vertical Characterization of Aerosol Particle Composition in Beijing, China: Insights From 3‐Month Measurements With Two Aerosol Mass Spectrometers

“…Vertical measurements can be an essential complement to characterize the formation mechanisms of secondary aerosol species and evaluate the roles of regional transport and local emissions in haze formation . For example, previous vertical measurements on the meteorological towers in Beijing and Tianjin showed complex vertical distributions and distinct layered structures of PM and gaseous pollutants (Chan et al, 2005;Han et al, 2015;Meng et al, 2008;Wang, Zhou, et al, 2016). However, most of these studies are limited by the offline filter sampling with relatively low time resolution (~24 hr), which neither reveals the rapid evolution of haze nor the variations of aerosol composition within low boundary layer.…”

Vertical structures of physical and chemical properties of urban boundary layer and formation mechanisms of atmospheric pollution

“…市高层同步观测的重要性和必要性. Han等人 [36] 通过 分析天津255 m气象塔所采集的4个不同高度处PM 10 样品的化学组分也发现地面一次排放源的影响随高 度的增加而降低, 而受区域输送影响更大的二次组 分贡献量则随高度的增加而升高. 基于2014年亚太 经合组织峰会(APEC)期间的北京325 m气象塔垂直 观测, Chen等人 [31] 和Xu等人 [37] [37] , 说明区域减排的同时需要同步加强局 地排放管控.…”

Atmospheric Signature and Potential Sources of Rare Earth Elements in Size-Resolved Particulate Matter in a Megacity of China

“…Before and after sampling, all filters were conditioned for 48 h in darkened desiccators prior to gravimetric determination. Then the filters were weighted on an electronic microbalance (AX205, Mettler-Toledo, LLC, with a ±0.01 mg sensitivity) in a weighing lab under controlled temperature (20 ± 1°C) and relative humidity (RH) (40 ± 3%) conditions (Han et al, 2015). The filters were sealed in polyethylene fiber boxes with a cover during transport to the sampling sites or back to the laboratory to avoid contamination .…”

“…Then, the samples were digested using progressive settings, and subsequently, the leaching solution was transferred to a volumetric flask and diluted to 50 mL with deionized water. Inductively coupled plasma atomic emission spectroscopy (ICP 9000 (N+M) Thermo Electron Corporation, USA) was used to determine the concentrations of Al present in the samples (Han et al, 2015). The determination of the REE concentrations was performed via inductively coupled plasma mass spectrometry (ICP-MS, Thermo, X serial, USA) (Kulkarni et al, 2007a;.…”