About
35
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Introduction
My research focuses on traffic-related air pollution, clean transportation, and environmental justice. I extensively utilized open-access data, big data analytics, and machine-learning methods to enhance the spatiotemporal resolution and dynamics of on-road emission mapping and air quality simulations. My work also encompasses sustainable transportation, including the promotion of new energy vehicles and their interactions with air quality, energy systems, and climate.
Current institution
Additional affiliations
July 2022 - December 2024
Education
September 2017 - June 2022
September 2013 - June 2017
Publications
Publications (35)
The adoption of zero-emission vehicles (ZEVs) offers multiple benefits for the climate, air quality, and public health by reducing tailpipe emissions. However, the environmental justice implications of the nonexhaust emissions from future ZEV fleets for near-roadway communities remain unclear. Here, we model the on-road fine particulate matter (PM2...
Implementing temporary traffic control measures is a common strategy to prevent air pollution and alleviate traffic congestion during mega-events. Accurate assessment of event-time vehicular emissions is useful for local authorities to develop effective policies. However, many previous assessments were based on policy-based scenarios, which often f...
Real-world heavy-duty diesel trucks (HDTs) were found to emit far more excess nitrogen oxides (NOx) and black carbon (BC) pollutants than regulation limits. It is essential to systematically evaluate on-road NOx and BC emission levels for mitigating HDTs emissions. This study launched 2109 plume chasing campaigns for NOx and BC emissions of HDTs ac...
In response to climate change, China is making great efforts to increase the green area for carbon sequestration. Road verges, as marginal land with favorable conditions for plant growth and ease of transportation, can be used for biomass production, but the biomass production and carbon sequestration potential have not been assessed. Here, we mapp...
Vehicle emissions in China have been decoupled from the rapid motorization owing to the comprehensive control strategies. China’s increasingly ambitious goals for better air quality are calling for deep emission mitigation, posing a need to develop an up-to-date emission inventory that can reflect the fast-developing policies on vehicle emission co...
The Surface Urban Energy and Water Balance Scheme (SUEWS) has recently been introduced to include a bottom-up approach to modeling carbon dioxide (CO2) emissions and uptake in urban areas. In this study, SUEWS is evaluated against the measured eddy covariance (EC) turbulent fluxes of sensible heat (QH), latent heat (QE), and CO2 (FC) in a densely b...
China is facing the challenge of synergistic reduction of air pollutants and CO2 emissions. However, the studies on its historical progress and future priorities are insufficient. This study compiled China's emission inventory of air pollutants and CO2 from 2005 to 2021 (ABaCAS-EI v2.0 dataset) based on a unified emission-source framework by consid...
On-road ammonia (NH3) emissions play a significant role in fine particulate matter (PM2.5) formation in urban areas, posing severe risks for human health. Limited studies have depicted the spatial and temporal variations of on-road NH3 emissions, in particular lacking detailed quantification of their contributions within densely populated areas. In...
The Surface Urban Energy and Water Balance Scheme (SUEWS) has recently been introduced to include a bottomup approach to modelling carbon dioxide (CO2) emissions and sink in urban areas. In this study, SUEWS is evaluated against radiation flux observations and eddy covariance (EC) measured turbulent fluxes of sensible heat (QH), latent heat (QE), a...
Ammonia (NH3) plays a vital role in the formation of fine particulate matter (PM2.5). Prior studies have primarily focused on the control of agricultural NH3 emissions, the dominant source of anthropogenic NH3 emissions. The air quality impact from vehicular NH3 emissions, which could be particularly important in urban areas, has not been adequatel...
China is facing the challenge of synergistic reducing air pollutants and CO2 emissions in the coming decades. The coupled emission inventory of air pollutants and CO2 is a prerequisite to designing the synergetic emission reduction strategy. This study compiled China’s emission inventory of air pollutants and CO2 during 2005–2021 (ABaCAS-EI v2.0 da...
On-road ammonia (NH3) emissions play a significant role in fine particulate matter (PM2.5) formation in urban areas, posing severer risks for human health. Limited studies have depicted the spatial and temporal variations of on-road NH3 emissions, in particular lacking detailed quantification of their contributions within densely-populated areas. I...
During the COVID-19 lockdown, the dramatic reduction of anthropogenic emissions provided a unique opportunity to investigate the effects of reduced anthropogenic activity and primary emissions on atmospheric chemical processes and the consequent formation of secondary pollutants. Here, we utilize comprehensive observations to examine the response o...
Assessing the disparities of urban-rural air quality response to changes in emissions is essential for the development of effective air pollution mitigation strategies in megacities. However, meteorology and nonlinear atmospheric chemistry complicate the determination of emission-air quality responses. Here, we established a machine� learning (ML)-...
On-road vehicle emissions are a major contributor to significant atmospheric pollution in populous metropolitan areas. We developed an hourly link-level emissions inventory of vehicular pollutants using two land-use machine learning methods based on road traffic monitoring datasets in the Beijing–Tianjin–Hebei (BTH) region. The results indicate tha...
During the COVID-19 lockdown, the dramatic reduction of anthropogenic emissions provided a unique opportunity to investigate the effects of reduced anthropogenic activity and primary emissions on atmospheric chemical processes and the consequent formation of secondary pollutants. Here, we utilize comprehensive observations to examine the response o...
![Fig. 5 Fitted splines for Ψ1[population density], Ψ16[D_logistics], and...](profile/Yifan-Wen/publication/354710907/figure/fig4/AS:1071390564311040@1632450824457/Fitted-splines-for-PS1population-density-PS16D-logistics-and-PS17D-CBD-for-a-CO2_Q320.jpg)
The development of intelligent approaches to quantify and mitigate on-road emissions is essential for urban and transportation sustainability for global megacities. Here, we utilize high-density traffic monitoring data and land use data to train random forest models capable of accurately predicting dynamic, link-level vehicle emissions. A total of...
Significance
We capitalize on large variations of urban air quality during the COVID-19 pandemic and real-time observations of traffic, meteorology, and air pollution in Los Angeles to develop a machine-learning air pollution prediction model. Such a model can adequately account for the nonlinear relationships between emissions, atmospheric chemist...
On-road vehicle emissions are a major contributor to significant atmospheric pollution in populous metropolitan areas. We developed an hourly-based, link-level emissions inventory of vehicular pollutants using two land-use machine learning methods based on the datasets of road traffic monitoring in the Beijing-Tianjin-Hebei (BTH) region. The result...
Black carbon (BC) is the most potent light-absorbing component of particulate matter and can have a significant warming impact. On-road vehicles are a major source of BC and a significant contributor to global warming. This paper establishes an updated inventory to quantify the mitigation potential of efforts to control BC emissions from on-road tr...
Start emissions from gasoline light-duty passenger vehicles (LDPVs) remain an important source of emissions modeling. This study measured start emissions of gaseous pollutants and solid particle number based on dynamometer tests for a fleet of 111 LDPVs in China, and selected a portion of samples to be tested under low temperature or shorter soak c...
The pandemic of coronavirus disease 2019 (COVID-19) resulted in a stringent lockdown in China to reduce the infection rate. We adopted a machine learning technique to analyze the air quality impacts of the COVID-19 lockdown from January to April 2020 for six megacities with different lockdown durations. Compared with the scenario without a lockdown...
The high populations of vehicles in global megacities have raised serious mobility and sustainability challenges, such as traffic congestion, air pollution deterioration and energy consumption issues. Detailed emission inventories at the link level are a prerequisite to accurately quantifying ambient pollution concentrations and identifying hotspot...
An important component of air quality engineering is quantifying in-use, fleet-average emission factors, and the spatial patterns of vehicle emissions. We report here that an absolute principal component score (APCS) analysis of on-road mobile measurements is a straightforward, efficient method for identifying the major contributors of traffic-rela...
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Promising applications of metal-organic frameworks (MOFs) in various fields have raised concern over their environmental fate and safety upon inevitable discharge into aqueous environments. Currently, no information regarding the transformation processes of MOFs is available. Due to the presence of repetitive π-bond structure and semi-conductive pr...
