Shuangliang Ma

Bio: Shuangliang Ma is an academic researcher. The author has contributed to research in topics: Environmental science & Pollution. The author has an hindex of 1, co-authored 1 publications receiving 41 citations.

Multi-model Evaluation and Bayesian Model Averaging in Quantitative Air Quality Forecasting in Central China

Abstract: 1 Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research, Institute of Heavy 5 Rain, China Meteorological Administration, Wuhan, China 6 2 Henan Key Laboratory of Environmental Monitoring Technology, Henan Ecological 7 Environment Monitoring Center, Henan, China 8 3 Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, 9 Nanjing University of Information Science and Technology, Nanjing, China 10 11 ∗ Corresponding author. Tel: 86-027-81804946; Fax: 86-027-81804916 12 E-mail address: 573537681@qq.com 13 xf_zhi@163.com 14

Weather reduced the annual heavy pollution days after 2016 in Beijing

Abstract: The numbers of heavy air pollution events per year in Beijing have decreased significantly since 2017. To find out the reasons and how meteorology and emissions control have played a role in this change, we used the WRF-SMOKE-CMAQ modeling system to reconstruct the characteristics of the fine particulate matter (PM2.5) concentrations from 2013 to 2019. The model system performed well, and the correlation coefficients (R) between the simulated and observed daily PM2.5 concentrations were all above 0.64. The model results also show that the meteorology contributed approximately ±5 μg/m3 to the annual average PM2.5 concentrations. More interestingly, the coincidence degrees of the simulated PM2.5 concentrations to the heavy pollution (daily PM2.5 concentration > 150 μg/m3) dates decreased significantly after 2016. Meteorology plays an important role in reducing the number of heavy pollution days. According to the model results under the same emission scenarios, the average numbers of heavy pollution days from 2017 to 2019 decreased by 33% compared to the period from 2013 to 2016, while the numbers of good days changed by less than 1%. These results also indicate that meteorology made a significant contribution to decreasing the number of heavily polluted days after 2016.

[Pollution Characterization, Source Identification, and Health Risks of Atmospheric Particle-Bound Heavy Metals in PM2.5 in Zhengzhou City: Based on High-resolution Data].

Abstract: In order to study the pollution characteristics and sources of heavy metals in urban atmospheric PM2.5, 21 elements in atmospheric PM2.5 in Zhengzhou City were detected using an online metal analyzer during July and October 2017 and January and April 2018, and the changes in heavy metal concentrations were analyzed. Heavy metals were traced by enrichment factors, principal component analysis, and potential source function. The US EPA risk assessment model was used to assess their health risks. The results showed that:the concentrations of K, Zn, Mn, Pb, Cu, As, Cr, and Se increased with the increase in pollution level. The results of enrichment factors and principal component analysis showed that the main sources of heavy metals were crust, mixed combustion, industry, and motor vehicles. The characteristic radar charts showed that the pollution dominated by crustal sources mainly occurred in spring and winter, whereas the pollution dominated by mixed combustion sources mainly occurred in winter. Pb, As, and Ni were greatly affected by the transport of a fen nutrient-laden plain, Beijing-Tianjin-Hebei, and southern Henan, whereas Cd was greatly affected by the northwest region of the sampling site. As presented a significant carcinogenic risk in both adults and children, whereas Pb and Sb presented a significant non-carcinogenic risk in children.

PM2.5 Pollution Modulates Wintertime Urban‐Heat‐Island Intensity in the Beijing‐Tianjin‐Hebei Megalopolis, China

Abstract: Heavy PM2.5 (particulate matter with aerodynamic diameter equal to or less than 2.5 mu m) pollution and urban heat island (UHI) pose increasing threats to human health and living environment in populated cities. However, how PM2.5 pollution affects the UHI intensity (UHII) has not been fully understood. The impacts of PM2.5 on the wintertime UHII in the Beijing-Tianjin-Hebei megalopolis of China are explored during 2013-2017. The results show that the UHII at the time of daily maximum/minimum temperature (UHIImax/UHIImin) exhibits a decreasing/increasing tendency as PM2.5 concentration increases, causing a continuous decrease in the diurnal temperature range. These effects are mediated via aerosol-radiation interaction (aerosol-cloud interaction) under clear-sky (cloudy) condition. The changes in PM2.5 concentration further cause different relative trends of UHII(ma)x/UHIImin/diurnal temperature range across different cities in the Beijing-Tianjin-Hebei region, which are likely related to the differences in both the PM2.5 composition and city size. This study provides insights on how air pollution affects urban climate and would help to design effective mitigation strategies. Plain Language Summary A detailed understanding of the relationship between PM2.5 (particulate matter with aerodynamic diameter equal to or less than 2.5 mu m) and the urban heat island (UHI) effect is significant for climate change adaption, planning, and sustainable development in urban regions. While the Beijing-Tianjin-Hebei (BTH) megalopolis of China is among the areas with the highest population densities and fastest urbanization rates in the world, the impacts of PM2.5 pollution on UHI, along with their regional differences in the BTH megalopolis, remain unclear. This study demonstrates that different PM2.5 concentrations in the BTH region pose various influences on the UHI intensities and their change rates in different cities of varying sizes. The UHI intensities during daytime and nighttime, respectively, exhibit weakening and strengthening tendency as PM2.5 concentration increases. These effects are mediated via aerosol-radiation interaction under clear-sky condition and aerosol-cloud interaction in cloudy weather. The relative changes in the UHI magnitudes were mainly determined by PM2.5 composition and city size. The asymmetrical influences of PM2.5 on the daytime and nighttime UHI intensities caused continuous decreases in the diurnal temperature ranges in the urban areas as the pollution level increased. Our study improves the understanding of urban climate affected by air pollution and provides a scientific basis for the mitigation of UHI impacts.

The significant impact of aerosol vertical structure on lower atmosphere stability and its critical role in aerosol–planetary boundary layer (PBL) interactions

Abstract: . The aerosol–planetary boundary layer (PBL) interaction was proposed as an important mechanism to stabilize the atmosphere and exacerbate surface air pollution. Despite the tremendous progress made in understanding this process, its magnitude and significance still have large uncertainties and vary largely with aerosol distribution and meteorological conditions. In this study, we focus on the role of aerosol vertical distribution in thermodynamic stability and PBL development by jointly using micropulse lidar, sun photometer, and radiosonde measurements taken in Beijing. Despite the complexity of aerosol vertical distributions, cloud-free aerosol structures can be largely classified into three types: well-mixed, decreasing with height, and inverse structures. The aerosol–PBL relationship and diurnal cycles of the PBL height and PM 2.5 associated with these different aerosol vertical structures show distinct characteristics. The vertical distribution of aerosol radiative forcing differs drastically among the three types, with strong heating in the lower, middle, and upper PBL, respectively. Such a discrepancy in the heating rate affects the atmospheric buoyancy and stability differently in the three distinct aerosol structures. Absorbing aerosols have a weaker effect of stabilizing the lower atmosphere under the decreasing structure than under the inverse structure. As a result, the aerosol–PBL interaction can be strengthened by the inverse aerosol structure and can be potentially neutralized by the decreasing structure. Moreover, aerosols can both enhance and suppress PBL stability, leading to both positive and negative feedback loops. This study attempts to improve our understanding of the aerosol–PBL interaction, showing the importance of the observational constraint of aerosol vertical distribution for simulating this interaction and consequent feedbacks.

Abnormally shallow boundary layer associated with severe air pollution during the COVID-19 lockdown in China.

Abstract: After the 2020 Lunar New Year, the Chinese government implemented a strict nationwide lockdown to inhibit the spread of the Coronavirus Disease 2019 (COVID-19). Despite the abrupt decreases in gaseous emissions caused by record-low anthropogenic activities, severe haze pollution occurred in northern China during the COVID lockdown. This paradox has attracted the attention of both the public and the scientific community. By analyzing comprehensive measurements of air pollutants, planetary boundary layer (PBL) height, and surface meteorology, we show that the severe air pollution episode over northern China coincided with the abnormally low PBL height, which had reduced by 45%, triggering strong aerosol-PBL interactions. After dynamical processes initiated the temperature inversion, the Beijing metropolitan area experienced a period with continuously shallow PBLs during the lockdown. This unprecedented event provided an experiment showcasing the role of meteorology, in particular, aerosol-PBL interactions in affecting air quality.