Dongsheng Ji

• PhD
• Professor at Institute of Atmospheric Physics, Chinese Academy of Sciences

Scientific knowledge on the chemical compositions of fine particulate matter (PM 2.5 ) is essential for properly assessing its health and climate effects, and for decisionmakers to develop efficient mitigation strategies. A high-resolution PM 2.5 chemical composition dataset (CAQRA-aerosol) is developed in this study, which provides hourly maps of...

Purpose of Review Despite significant improvements in particulate pollution, ozone (O₃) levels have unexpectedly worsened in Shandong Province, China (SDP), which is one of the world’s hotspots for O₃ pollution. This review aims to summarize O₃ pollution studies in SDP and highlight the challenges faced by current research efforts. Recent Findings...

Aerosol chemistry in China has undergone significant transformation due to stringent emission control measures, leading to great shifts in aerosol composition and formation mechanisms. This study investigates the summer chemical evolution of aerosol species in Beijing over the past decade based on two summertime measurements using aerosol chemical...

Situated in close proximity to the Korea Peninsula and the Japan Islands, Shandong Province in China (SDP) has emerged as a focal point for global attention due to its significant surface ozone (O 3 ) and aerosol pollution. Despite this attention, there are notable gaps in knowledge across various interconnected research domains, encompassing clima...

Organic aerosols (OA) constitute an important fraction of fine particulate matter (PM2.5) air pollution, yet accurate and efficient OA modeling within chemical transport models (CTM) remains a challenge. Volatility basis set (VBS) schemes for OA have demonstrated improved performance in simulating OA, particularly for primary organic aerosol (POA),...

Atmospheric age reflects how long particles have been suspended in the atmosphere, which is closely associated with the evolution of air pollutants. Severe regional haze events occur frequently in China, influencing air quality, human health, and regional climate. Previous studies have explored the characteristics of mass concentrations and composi...

Ammonia (NH3) is critical to the nitrogen cycle and PM2.5 formation, yet a great deal of uncertainty exists in its urban emission quantifications. Model-underestimated NH3 concentrations have been reported for cities, yet few studies have provided an explanation. Here, we explore reasons for severe WRF-Chem model underestimations of NH3 concentrati...

Secondary organic aerosol (SOA) is an important component of atmospheric fine particulate matter (PM2.5), with contributions from anthropogenic and biogenic volatile organic compounds (AVOC and BVOC) and semi- (SVOC) and intermediate volatility organic compounds (IVOC). Policymakers need to know which SOA precursors are important but accurate simul...

Particulate matter (PM) inhaled into human lungs causes oxidative stress and adverse health effects through antioxidant depletion (oxidative potential, OP). However, there is limited knowledge regarding the association between the lung-deposited dose (LDD) of PM and OP in extrathoracic (ET), tracheobronchial (TB), and pulmonary (P) regions of human...

Atmospheric age reflects how long particles have been suspended in the atmosphere, which is closely associated with the evolution of air pollutants. Severe regional haze events occur frequently in China, influencing air quality, human health, and regional climate. Previous studies have explored the characteristics of mass concentrations and composi...

Secondary organic aerosols (SOA) are an important component of atmospheric fine particulate matter (PM2.5) in China, and elsewhere, with contributions from anthropogenic and biogenic volatile organic compounds (AVOC and BVOC) and semi- (SVOC) and intermediate volatility organic compounds (IVOC). Policy makers need to know which SOA precursors are i...

Long-term continuous hourly measurements of ambient volatile organic compounds (VOCs) are scarce at the regional scale. In this study, a one-year hourly measurement campaign of VOCs was performed in Lvliang, Linfen, and Yuncheng in the heavily polluted Fenhe Plain region in China. The VOC average (±standard deviation, std) concentrations in Lvliang...

The atmospheric chemistry of nitrous acid (HONO) has received extensive attention because of its significant contribution to hydroxyl (OH) radicals. Heterogeneous reaction of NO2 is an important HONO source, and its reaction mechanism is affected by many factors, such as concentration of gaseous NO2, surface adsorbed water, relative humidity and te...

Limited by the scarcity of in situ vertical observation data, the influences of biomass burning in Southeast Asia on major atmospheric carbonaceous compositions in downwind regions have not been thoroughly studied. In this study, aircraft observations were performed to obtain high time-resolved in situ vertical distributions of black carbon (BC) as...

Fireworks are widely used in celebrations worldwide. The effects of fireworks on the physicochemical characteristics of atmospheric particles are well documented. However, the influence of firework burning on ambient volatile organic compound (VOC) emissions remains unclear. To determine the impact of firework-burning events on VOC emissions, ambie...

A comprehensive year-round field campaign was conducted in the coastal city of Ningbo, China to examine the driving factors of oxidative potential (OP) of PM2.5 and hence its potential health impacts. Using dithiothreitol (DTT) cell-free assay, OP of water-soluble (OPws) and methanol-soluble components (OPmeth) of PM2.5-based samples were measured....

Atmospheric nitrous acid (HONO) is a dominant precursor of hydroxyl (OH) radicals, and its formation mechanisms are still controversial. Few studies have simultaneously explored effects of different combustion processes on HONO sources. Hereby, synchronous HONO measurement in urban (BJ), suburban (XH) and rural (DBT) areas with different combustion...

Online detection of bioaerosols based on the light-induced fluorescence (LIF) technique is still challenging due to the complexity of bioaerosols and the external/internal mixing with nonbiological fluorescent compositions. Although many lab studies have measured the fluorescence properties of the biological and nonbiological materials, there is st...

Accompanied by the continuous declines of PM2.5, O3 pollution has become increasingly prominent and has been targeted by the Government of China to protect climate, ecosystem, and human health. Although satellite retrievals of column O3 have been operated for decades and nationwide monitoring of ground-level O3 has been offered since 2013 in China,...

HONO concentrations in Beijing (BJ) and Sanmenxia (SMX) were simultaneously measured in winter with a duration of 1 month, and the sources and sinks of HONO in the two cities were comparably analyzed. BJ and SMX had different pollution characteristics. Direct vehicle emission made a contribution to observed HONO of about 28% in BJ, whereas it contr...

Recently, ozone (O3) pollution has become a significant problem for Beijing owing to its high traffic volume. To improve the simulation of street-scale nitrogen oxides (NOx) and O3, an integrated air quality modeling system coupling regional urban/street (IAQMS-street) was developed for Beijing. A weather research and forecasting atmospheric model,...

The Fenwei Plain (FWP) continues to be one of the most polluted regions in China despite the improvement of air quality in recent years. However, our understanding of aerosol optical properties (AOP) and its relationship with aerosol composition particularly in cold season is far from complete. Here we conducted three-month measurements of AOP from...

To better understand the change characteristics and reduction in organic carbon (OC) and elemental carbon (EC) in particulate matter (PM) with a diameter of ≤2.5 μm (PM2.5) driven by the most stringent clean air policies and pandemic-related lockdown measures in China, a comprehensive field campaign was performed to measure the carbonaceous compone...

Tropospheric ozone (O3) pollution, as one of the major environmental problems, poses a significant threat to human health and ecosystems. In the past, the study of O3 risk has only focused on the daytime, neglecting to analyze the role of nighttime concentrations, which may have led to underestimation of O3 exposure hazards. In this study, we inves...

The influences of strong El Niño events (1997/98 and 2015/16) on summertime near-surface ozone (O3) concentrations over China are investigated using the GEOS-Chem model. The results show that near-surface O3 concentrations increased by a maximum of 6 ppb (parts per billion) during the summer of the developing phase of the 1997/98 El Niño in northea...

Particulate matter (PM) pollution in high emission regions will affect air quality, human health and climate change on both local and regional scales, and thus attract worldwide attention. In this study, a comprehensive study on PM2.5 and its chemical composition were performed in Yuncheng (the most polluted city of Fen-Wei Plain of China) from Nov...

Since NOx has decreased significantly, ozone formation sensitivity in urban areas has gradually shifted from VOC-limited to NOx-limited. Ozone is usually formed at high altitudes. However, due to a lack of vertical gradient observation data support, the evidence of high-altitude sensitivity change is still not conclusive. To confirm this issue, ozo...

Atmospheric deposition of dissolved organic carbon (DOC) is equivalent to the magnitude of riverine export of DOC to the oceans. Interpreting the fluctuations of DOC in precipitation is therefore useful in understanding the global carbon balance. This study measured DOC in 137 rain events collected from November 2016 to November 2020 at a rural sit...

Although combustion is considered a common source of ammonia (NH3) in the atmosphere, field measurements quantifying such emissions of NH3 are still lacking. In this study, online measurements of NH3 were performed by a cavity ring-down spectrometer, in the cold season at a rural site in Xianghe on the North China Plain. We found that the NH3 conce...

Air quality has been improved significantly from 2017 to 2020 in Fenhe Plain, one of the most polluted regions in China. However, severe haze episodes from days to weeks were still frequently observed in cold seasons, and the sources and formation mechanisms especially organic aerosols are poorly understood due to the limited highly time-resolved m...

Coal-to-clean energy programs (coal bans) can improve air quality and public health and welfare. However, the field measurements taken in rural areas are still insufficient to evaluate the efficacy of coal bans in China. In this study, more than three years of observations were made on organic carbon (OC), elemental carbon (EC, also called black ca...

High emissions of particulate pollutants in a regional scale adversely affect global air quality, health welfare and climate change. The Fen-Wei Plain (FWP) of China is among the most polluted regions of China and worldwide due to its thriving coal and coking industry. However, the joint regional observations are scarce in the FWP of China. In this...

A field campaign was conducted to study the PM2.5 and atmospheric gases and aerosol's components to evaluate the efficacy of radical measures implemented by the Chinese government to improve air quality during the 2016 G20 Summit in Hangzhou China. The lower level of PM2.5 (32.48 ± 11.03 µg/m³) observed during the control period compared to pre-con...

Absorbing carbonaceous aerosols, i.e. black and brown carbon (BC and BrC), affected heavily on climate change, regional air quality and human health. The nationwide lockdown measures in 2020 were performed to against the COVID-19 outbreak, which could provide an important opportunity to understand their variations on light absorption, concentration...

The homoscedasticity assumption (the variance of the error term is the same across all the observations) is a key assumption in the ordinary linear squares (OLS) solution of a linear regression model. The validity of this assumption is examined for a multiple linear regression model used to determine the source contributions to the observed black c...

This study used a chemical transport model to investigate the response of secondary inorganic aerosols (SIA) to chemical processes and its precursor emissions over northern and southern city-clusters of China in January 2014. Unexpectedly, SIA concentrations with low levels of precursor emissions were much higher over the southern regions than thos...

To study the aerosol chemistry and regional transport changes in Beijing under different stagnant meteorological conditions, a simultaneous combined observation of the nonrefractory submicron aerosol (NR-PM1) chemical compositions and vertical wind profiles was conducted at an urban site (Beijing) and a regional background site (Xinglong) in the No...

High ozone concentrations promote the formation of nitrate in the nocturnal residual layer (RL), but this phenomenon has not been confirmed by direct observation. In this study, ozone, water-soluble ions in PM2.5 and the corresponding meteorological factors in the stable boundary layer, RL and mixing layer were observed by portable instruments carr...

For the first time in the North China Plain (NCP) region, we investigated the seasonal variations in submicron particles (NR-PM1) and their chemical composition at a background mountainous site of Xinglong using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer. The average concentration of NR-PM1 was highest in autumn (15.1 µgm-...

Recent Chinese air pollution actions have significantly lowered the levels of fine particulate matter (PM2.5) in North China via controlling emissions of sulfur dioxide (SO2) and nitrogen oxides (NO x ) together with primary aerosols, while the emissions of another precursor, ammonia (NH3), have not yet been regulated. This raises a question that h...

The high frequency of new particle formation (NPF) events observed under polluted atmospheric conditions is still poorly understood. To improve our understanding of NPF and its effects, the particle number size distribution (3–1000 nm) and submicron particle chemical composition were measured from 4 November 2017 to 17 January 2018 in suburban Beij...

Based on laboratory studies and field observations, a new parameterization of uptake coefficients for heterogeneous reactions on multi-component aerosols is developed in this work. The equivalent ratio (ER) of inorganic aerosol is used to establish the quantitative relationship between the heterogeneous uptake coefficients and the composition of ae...

Lung cancer (LC) mortality, as one of the top cancer deaths in China, has been associated with increased levels of exposure to ambient air pollutants. In this study, different lag times on weekly basis were applied to study the association of air pollutants (PM2.5, PM10, and NO2) and LC mortality in Ningbo, and in subpopulations at different age gr...

The development of chemical transport models with advanced physics and chemical schemes could improve air-quality forecasts. In this study, the China Meteorological Administration Unified Atmospheric Chemistry Environment (CUACE) model, a comprehensive chemistry module incorporating gaseous chemistry and a size-segregated multicomponent aerosol alg...

The development of chemical transport models with advanced physics and chemical schemes could improve air-quality forecasts. In this study, the China Meteorological Administration Unified Atmospheric Chemistry Environment (CUACE) model, a comprehensive chemistry module incorporating gaseous chemistry and a size-segregated multicomponent aerosol alg...

The atmospheric oxidation capacity (AOC) and photochemical reactivity are of increasing concern owing to their roles in photochemical pollution. The AOC and OH reactivity were evaluated based on simultaneous measurements of volatile organic compounds (VOCs), trace gases and photolysis frequency during summer and winter campaigns at a suburban site...

The atmospheric oxidizing capacity (AOC) is the essential driving force of tropospheric chemistry, but its quantitative representation remains limited. This study presents the detailed evaluation of AOC in the megacity of Beijing based on newly developed indexes that represent the estimated oxidative capacity from the prospective of oxidation produ...

Aerosol size distribution and chemical composition are found to have significant effects on its hygroscopicity, acidity/alkalinity and light extinction. Heavy haze pollution occurred frequently in the wintertime of NCP, with long duration time and large impact area, which had important influences on air quality and human health. However, the study...

This study aimed to characterize PM2.5-bound trace elements in Northern Zhejiang Province (NZP), one of the most economically prosperous regions in China, and assess the associated health risks for the general populations. A year-long sampling campaign was conducted at four sites representative of urban, suburban, and rural areas of NZP. The averag...

Nitrate-driven aerosol pollution frequently occurs during winter over the North China Plain (NCP). Extensive studies have focused on inorganic nitrate formation, but few have focused on organic nitrates in China, precluding a thorough understanding of the nitrogen cycle and nitrate aerosol formation. Here, the inorganic (NO3,inorg) and organic nitr...

A seven-year long-term comprehensive measurement of non-refractory submicron particles (NR-PM1) in autumn and winter in Beijing from 2012 to 2018 was conducted to evaluate the effectiveness of the clean air actions implemented by the Chinese government in September 2013 on aerosols from different sources and chemical processes. Results showed that...

Gaseous nitrous acid (HONO) is a crucial precursor of the hydroxyl (OH) radical, which is a "detergent" in the atmosphere. Nowadays, HONO formation mechanisms at polluted urban areas are controversial, which restricts the understanding of atmospheric oxidative capacity and radical cycling. Herein, multiday vertical observation of HONO and NO x was...

Vertical distribution of black carbon (BC) determines the layer where its heating impacts exert. This study presents continuous and simultaneous measurements at surface and on a mountain site above the wintertime planetary boundary layer influenced by uplifted surface anthropogenic emissions. BC was observed efficiently transported upwards by dayti...

The size-resolved (200–700 nm) mixing state and optical properties of black carbon (BC) in Beijing in the spring of 2019 were investigated using a tandem system consisting of an aerodynamic aerosol classifier, a nephelometer, and a single particle soot photometer. The results showed that the coating thickness distribution exhibited a clear bimodal...

In this study, Bigg cloud chamber was used to determine the concentrations of ice nucleating particles (INPs) in the temperature range from −15 to −30 °C in Beijing during the spring of 2017. The concentrations were compared with historical results observed by a similar instrument in Beijing, showing that the INP concentration in 2017 was generally...

Hydroxyl (OH) radicals, nitrate (NO3) radicals and ozone (O3) play central roles in the troposphere because they control the lifetimes of many trace gases that result from anthropogenic and biogenic origins. To estimate the air chemistry, the atmospheric reactivity and oxidation capacity were comprehensively analyzed based on a parameterization met...

The rapidly spread coronavirus disease (COVID-19) has limited people's outdoor activities and hence caused substantial reductions in anthropogenic emissions around the world. However, the air quality in some megacities has not been improved as expected due to the complex responses of aerosol chemistry to the changes in precursors and meteorology. H...

To control the spread of the novel coronavirus disease 2019 (COVID-19) in China, many anthropogenic activities were reduced and even closed on the national scale. To study the impact of this reduction and closing down, hourly concentrations of PM2.5-related elements were measured at a rural site before (12–25 January 2020), during (26 January–9 Feb...

Worldwide attention has been focused on air pollution associated with vehicle emissions. With the highest number of vehicles, Beijing has experienced air pollution related to vehicle emissions. To better recognize the contributions of vehicle emissions to organic carbon (OC) and elemental carbon (EC), hourly measurements of OC and EC in PM2.5 were...

Nitrate (NO3⁻), sulfate (SO4²⁻) and ammonium (NH4⁺) in airborne fine particles (PM2.5) play a vital role in the formation of heavy air pollution in northern China. In particular, the increasing contribution of NO3⁻ to PM2.5 has attracted worldwide attention. In this study, a highly time-resolved analyzer was used to measure water-soluble inorganic...

Although much attention has been paid to investigating and controlling air pollution in China, the trends of air-pollutant concentrations on a national scale have remained unclear. Here, we quantitatively investigated the variation of air pollutants in China using long-term comprehensive data sets from 2013 to 2017, during which Chinese government...

Nitrate and sulfate are two key components of airborne particulate matter (PM). While multiple formation mechanisms have been proposed for sulfate, current air quality models commonly underestimate its concentrations and mass fractions during northern China winter haze events. On the other hand, current models usually overestimate the mass fraction...

Severe events of wintertime particulate air pollution in Beijing (winter haze) are associated with high relative humidity (RH) and fast production of particulate sulfate from the oxidation of sulfur dioxide (SO2) emitted by coal combustion. There has been considerable debate regarding the mechanism for SO2 oxidation. Here we show evidence from fiel...

Abstract. For the first time in the North China Plain (NCP), we investigated the seasonal variations of submicron particles (NR-PM₁) and its chemical composition at a background mountain station using Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS). The averaged NR-PM₁ were highest in autumn (15....

Regional haze pollution can normally be divided into four stages comprising pre-accumulation, explosion, duration and dissipation, under which the physiochemical characteristics of aerosols were clearly distinct. In this study, the chemical compositions and mixing state of aerosols and their source apportionments during a regional haze pollution pr...

The North China Plain has been identified as a global hotspot for ammonia (NH3). To date, NH3 surface observations in the region have mostly been obtained by passive samplers with a time resolution of weeks (e.g., AMoN-China), and few studies have been performed with fast-response instruments. Thus, the detailed temporal variation of NH3 concentrat...

To explore the impact of the “Coal to Gas” project on air pollution around Beijing, the pollution observation data during the heating periods (from Nov.15 to Mar.15) of 2017 and 2018 at Xianghe Observatory in Langfang, Hebei Province of China, were analyzed in combination with meteorological data and fuel incremental statistics. According to this p...

To what extent anthropogenic emissions could influence volatile organic compound (VOC) concentrations and related atmospheric reactivity is still poorly understood. China's 70th National Day holidays, during which anthropogenic emissions were significantly reduced to ensure good air quality on Anniversary Day, provides a unique opportunity to inves...

Severe wintertime PM2.5 pollution in Beijing has been receiving increasing worldwide attention, yet the decadal variations remain relatively unexplored. Combining field measurements and model simulations, we quantified the relative influences of anthropogenic emissions and meteorological conditions on PM2.5 concentrations in Beijing over the winter...

The fluorescence characteristics of particulate water-soluble organic compounds (WSOC) emitted by different power of coal-fired boilers (A total of 14 boilers including 1, 2, 4, 6, 10, 15, 20 tons steam per hour (t·h⁻¹)) in Lanzhou, an industrial city of northwest China, were analyzed by excitation-emission matrix (EEM) fluorescence spectroscopy. R...

An intensive and persistent regional ozone pollution event occurred over eastern China from 25 June to 5 July 2017. 73 out of 96 selected cities, most located in the Beijing-Tianjin-Hebei and the surrounding area (BTHS), suffered severe ozone pollution. A north-south contrast ozone distribution, with higher ozone (199 ± 33 μg/m³) in the BTHS and lo...

Although much effort has been put into studying air pollution, our knowledge of the mechanisms of frequently occurring intense haze episodes in China is still limited. In this study, using 3 years of measurements of air pollutants at three different height levels on a 325 m Beijing meteorology tower, we found that a positive aerosol–boundary layer...

The characteristics of ozone variations and the impacts of synoptic and local meteorological factors in northern China were quantitatively analyzed during the warm season from 2013 to 2017 based on multi-city in situ ozone and meteorological data as well as meteorological reanalysis. The domain-averaged maximum daily 8 h running average O3 (MDA8 O3...

To better investigate the characteristics and sources of trace elements (TEs) in PM2.5 in urban Beijing, a 1‐year hourly observation was continuously made using an online multi‐element analyzer from 1 June 2016 to 31 May 2017. The average concentrations of 14 individual TEs ranged from 1.1 (V) to 900 ng/m³ (K). The occurrence levels of most TEs of...