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684 results on '"Hopke, P. K."'

58. Evaluation of air quality changes in a Chinese megacity over a 15-year period (2006-2021) using PM2.5 receptor modelling

Author

0000-0001-6593-5593, Canals-Angerri, Anna, Lv, W., Zhuang, X., Shangguan, Y., Wang, Y., Kong, S., Hopke, P. K., Amato, Fulvio, Alastuey, Andrés, Van Drooge, Barend, Querol, Xavier, 0000-0001-6593-5593, Canals-Angerri, Anna, Lv, W., Zhuang, X., Shangguan, Y., Wang, Y., Kong, S., Hopke, P. K., Amato, Fulvio, Alastuey, Andrés, Van Drooge, Barend, and Querol, Xavier

Abstract

Air quality impairment has a massive impact on human health, with atmospheric particulate matter (PM) playing a major role. The People's Republic of China experienced a trend of increasing PM2.5 concentrations from 2000 to 2013. However, after the application of the Air Pollution Prevention and Control Action Plan and other related control measures, sharp decreases in air pollutant concentrations were particularly evident in the city of Wuhan (central China). This study analysed major changes in PM2.5 concentrations, composition and source apportionment (using receptor modelling) based on Wuhan's PM2.5 chemical speciation datasets from 2006 to 2007, 2019-2021 and contemporaneous gaseous pollutant values. Average SO2 concentrations decreased by 88%, from the first to the second period, mostly due to measures that reduced coal combustion. However, NO2 only declined by 25%, with policy measures likely being undermined by an increased number of vehicles. PM2.5 concentrations decreased by 65%, with the PM constituents each being affected differently. Coal combustion-related element concentrations, OC, SO42-, NH4+, EC, Cl-, Al, Ca, Cu, Fe, Co and NO3- decreased by 22-90%. Secondary inorganic aerosol (SIA) was initially dominated by (NH4)2SO4 (73%) in 2006, but later dominated by NH4NO3 (52%) in 2021. Receptor modelling identified major sources contributing to PM2.5: Mineral, road and desert dust (MRDD), Secondary sulphate (SECS), Secondary nitrate (SECN), Tungsten industry (W), Toxic Elements of Coal (TEC), Iron and Steel (IRONS), Coal Combustion (CC), Residential Heating (RH), Refinery (REF) and Traffic (TRF). In relative proportions, TEC (-83%), SECS (-64%) and SECN (-48%) reduced their contributions to PM2.5 whilst MRDD increased (+62.5%). Thus, the results indicate not only a drastic abatement of PM pollution in Wuhan but also a change in the sources of pollution, which requires further actions to reduce PM2.5 concentrations to health protective values. Secondary PM a

Published
2023

84. Drivers of civil aviation emissions in China: Considering spatial heterogeneity and interdependence.

Author

Ma, Simeng, Zheng, Wenhui, Han, Bo, Deng, Zhiqiang, Yu, Jinglei, Zhao, Jingbo, Zhang, Chen, Yu, Jian, and Hopke, Philip K.

Abstract

CO 2 and NO x emissions from aviation transportation are critical components of overall transportation-related emissions, significantly impacting both climate and air quality. To implement more targeted and effective measures for mitigating emissions in this sector, it is essential to conduct empirical analyses that deepen our understanding of the factors influencing aviation emissions. Previous studies have predominantly focused on emissions from the entire transportation sector, with limited research specifically addressing aviation emissions. Notably, past research has often overlooked the existence of spatial autocorrelation patterns in aviation emissions. Here, we developed a civil aviation emission inventory at the provincial scale for China using a bottom-up approach based on daily flight schedules from 2012 to 2019. By utilizing the STIRPAT and spatial Durbin models, we identified key factors affecting civil aviation CO 2 and NO x emissions and assessed their spatial effects at the provincial level in China. Spatial-temporal analysis revealed distinct patterns and spatial non-stationarity in CO 2 and NO x emissions from civil aviation. The results also highlighted that GDP, per capita GDP, the transportation price index, and per capita consumption expenditure positively drive. The results emphasize the importance of close collaboration among different provinces to effectively decarbonize and reduce pollution in the civil aviation sector given the significant observed spatial dependencies. These findings provide valuable insights for policymakers in formulating strategies to reduce aviation emissions and understanding the influence of different socioeconomic activities on emissions. [Display omitted] • An emission inventory for civil aviation in China from 2012 to 2019 is established. • A STIRPAT and spatial Durbin model are applied to assess key driving factor's impact. • A clustering or agglomeration effect is observed in China's aviation emissions. • Economic factors correlate positively emissions, transportation structure negatively. • Spatial dependence exists, emphasizing the need for collaboration to cut emissions. [ABSTRACT FROM AUTHOR]

Published
2025
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85. Increases in PM2.5 levels in Houston are associated with a highly recirculating sea breeze.

Author

Chao, Chun-Ying, Li, Wei, Hopke, Philip K., Guo, Fangzhou, Wang, Yuxuan, and Griffin, Robert J.

Subjects
CHANNELS (Hydraulic engineering), K-means clustering, PARTICULATE matter, MATRIX decomposition, AIR quality, SEA breeze
Abstract

Local land-sea breezes play an important role in coastal air quality because they circulate air between coastal/urban and marine areas, potentially causing the accumulation of pollutants. This has been observed for the secondary photochemical pollutant ozone. However, particulate matter (PM) also warrants investigation. To understand the complicated interactions between coastal urban air quality and a local land-sea breeze, we analyzed historical monitoring data from Houston, Texas, which is the fourth most populous city in the United States. Using k-means clustering algorithms to analyze wind data from Houston, we successfully identified a sea breeze recirculation cluster. Additionally, we performed positive matrix factorization on PM 2.5 (2.5 μm in diameter or smaller) composition data for 2010–2018 from Houston Deer Park #2 monitoring site, 5 km south of the industrialized Houston Ship Channel. The resulting eight factors indicated a variety of anthropogenic, natural, primary and secondary sources. Emphasizing the PM 2.5 sources in each of the wind clusters for June, July, and August, we discovered that on southernly wind and sea breeze recirculation days, the PM 2.5 concentrations are ∼30% higher than those under other wind patterns. Under southerly wind, 53% of PM 2.5 was attributed to long-range transport of soil and 15% to aged and fresh sea salt. In contrast, on days identified as being impacted by a sea breeze, 60% of PM 2.5 was attributed to anthropogenic emissions and only 15% to soil sources. Secondary organic aerosol from multiple sources also appeared to be important on sea breeze days. [Display omitted] [ABSTRACT FROM AUTHOR]

Published
2025
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