A Monitoring and Modeling Study to Investigate Regional Transport and Characteristics of PM2.5 Pollution

Abstract

In this study, the regional transport and characteristics of PM 2.5 pollution were examined through a case study in Beijing, China. The results from an intensive monitoring program indicate that the inorganic particles (sulfate, nitrate, and ammonium), organic carbons, and the elements accounted for 35.5, 24.2, and 15.3% of the total PM 2.5 on an annual average basis, respectively. The proportions of such PM 2.5 components also showed clear seasonal variations. An integrated MM5-CMAQ modeling system was then developed to examine the regional transport of PM 2.5 and its components in Beijing within four typical months of 2010. The results indicate that the annual average total trans-boundary contribution ratio (TBCR) is 42.2, 46.3, 77.4, and 61.6% for the concentrations of PM 2.5 , sulfate, nitrate, and ammonium, respectively. A logarithmic relationship was found between the total TBCR and the PM 2.5 concentrations in Beijing for different seasons. Further investigations showed that trans-boundary transport played a major role in Beijing's PM 2.5 concentrations during the period of high pollution levels, with an annual average TBCR of 54.6%. As a result, the control of PM 2.5 pollution in Beijing needs effective cooperation between Beijing and its surrounding regions, especially during periods of heavy pollution.

Investigation of Particulate Matter Regional Transport in Beijing Based on Numerical Simulation

“…The TBCR in summer is significant larger than winter, which is consistent with the findings by Lang et al (2013). Seasonal difference of meteorological condition combined with the distribution of emission is responsible for seasonal difference of TBCRs.…”

“…Most of the TBCR of PM in Beijing ranged from 30% to 40%. As meteorological conditions vary, the TBCR of PM 2.5 in Beijing has obvious seasonal variations, with the largest TBCR found in summer, followed by spring, autumn and winter (Lang et al, 2013). Although previous studies on regional transport in Beijing have been conducted, some issues, such as the relation of transport to meteorology and secondary aerosols, are still unclear to some extent.…”

“…The colour bar represents altitude, the white line represents the administrative boundaries of province. Lang et al (2013) Four typical months of 2010 CMAQ simulation using emission switch on/off method PM 2.5 : 42.2% Wang et al (2015cWang et al ( ) 2005 HYSPLIT simulation based on PSFC method PM 2.5 : 35.5% Zhang et al (2015bZhang et al ( ) 2013Zhang et al ( -2015 GEOS-Chem adjoint method PM 2.5 : 47.2% initial and boundary conditions were presented in He et al (2016b). The base run (hereafter refer to as BR) is simulated based on the CUACE default emission inventory with the replacement of vehicle emissions by high temporal-spatial resolution vehicle emissions (Jing et al, 2016).…”

Verification of Chemical Transport Models for PM2.5 Chemical Composition Using Simultaneous Measurement Data over Japan

“…In Beijing, China, PM 2.5 chemical compositions were measured during the period from December 2010 to January 2012, and the data were used to evaluate the performance of a CTM (CMAQ) (Lang et al, 2013 concentrations were underestimated in winter and well reproduced in summer, whereas NO 3 -concentrations were overestimated in spring and underestimated in summer. Foley et al (2010) compared concentrations simulated by CMAQ (v4.7) with observed data in winter and summer 2006; during both seasons, SO 4 2-concentrations were underestimated by 5% to 21%, and NO 3 -concentrations were underestimated by 7% to 45%.…”

Review on the Recent PM_2.5 Studies in China

“…모델링을 활용한 연구는 특정 지역의 오염사례뿐만 아니라 (Gao et al, 2014a;Lang et al, 2013), 중국 전체에 대한 오염물질의 배출 원 지역 (source region)간의 이동 및 기후변화에 미치는 영향을 산정하는 연구도 수행되었다 Ying et al, 2014).…”