Spatiotemporal Heterogeneity Analysis of Air Quality in the Yangtze River Delta, China

2021 ◽  
pp. 103603
Author(s):  
Lizhi Miao ◽  
Chengliang Liu ◽  
Xin Yang ◽  
Mei-Po Kwan ◽  
Kai Zhang
Keyword(s):  
Air Quality ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
Heterogeneity Analysis ◽  
Spatiotemporal Heterogeneity ◽  
The Yangtze River Delta

scholarly journals Source, transport and impacts of a heavy dust event in the Yangtze River Delta, China in 2011

2013 ◽  
Vol 13 (8) ◽  
pp. 21507-21540
Author(s):  
X. Fu ◽  
S. X. Wang ◽  
Z. Cheng ◽  
J. Xing ◽  
B. Zhao ◽  
...  
Keyword(s):  
Air Quality ◽  
Yangtze River ◽  
Eastern China ◽  
Yangtze River Delta ◽  
River Delta ◽  
Dust Particles ◽  
The Yangtze River ◽  
Dust Event ◽  
The Yrd ◽  
The Yangtze River Delta

Abstract. During 1 to 6 May 2011, a dust event was observed in the Yangtze River Delta region (YRD). The highest PM10 concentration reached over 1000 μg m−3 and the visibility was below 3 km. In this study, the Community Multi-scale Air Quality modeling system (CMAQ5.0) coupled with an in-line windblown dust model was used to simulate the formation, spatial and temporal characteristics of this dust event, and analyze its impacts on deposition and photochemistry. The threshold friction velocity for loose smooth surface in the dust model was revised based on Chinese data to improve the model performance. The comparison between predictions and observations indicates the revised model can reproduce the transport and pollution of the event. The simulation results show that the dust event was affected by formation and transport of Mongolian cyclone and cold air. Totally about 695 kt dust particles (PM10) were emitted in Xinjiang Province and Mongolia during 28 to 30 April, the dust band swept northern, eastern China and then arrived in the YRD region on 1 May 2011. The transported dust particles increased the mean surface layer concentrations of PM10 in the YRD region by 372% during 1 to 6 May and the impacts weakened from north to south due to the removal of dust particles along the path. Accompanied by high PM concentration, the dry deposition, wet deposition and total deposition of PM10 in the YRD reached 184.7 kt, 172.6 kt and 357.32 kt, respectively. These deposited particles are very harmful because of their impacts on urban environment as well as air quality and human health when resuspending in the atmosphere. Due to the impacts of mineral dust on atmospheric photolysis, the concentrations of O3 and OH were reduced by 1.5% and 3.1% in the whole China, and by 9.4% and 12.1% in the YRD region, respectively. The work of this manuscript is meaningful for understanding the dust emissions in China as well as for the application of CMAQ in Asia. It is also helpful to understand the formation mechanism and impacts of dust pollution in the YRD.

scholarly journals Quantification and evaluation of atmospheric ammonia emissions with different methods: a case study for the Yangtze River Delta region, China

2020 ◽  
Vol 20 (7) ◽  
pp. 4275-4294 ◽  
Author(s):  
Yu Zhao ◽  
Mengchen Yuan ◽  
Xin Huang ◽  
Feng Chen ◽  
Jie Zhang
Keyword(s):  
Air Quality ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
Emission Factors ◽  
River Delta ◽  
The Yangtze River ◽  
Nh3 Volatilization ◽  
Inorganic Aerosols ◽  
Emission Estimation ◽  
The Yangtze River Delta

Abstract. To explore the effects of data and method on emission estimation, two inventories of NH3 emissions of the Yangtze River Delta (YRD) region in eastern China were developed for 2014 based on constant emission factors (E1) and those characterizing agricultural processes (E2). The latter derived the monthly emission factors and activity data integrating the local information of soil, meteorology, and agricultural processes. The total emissions were calculated to be 1765 and 1067 Gg with E1 and E2, respectively, and clear differences existed in seasonal and spatial distributions. Elevated emissions were found in March and September in E2, attributed largely to the increased top dressing fertilization and to the enhanced NH3 volatilization under high temperature, respectively. A relatively large discrepancy between the inventories existed in the northern YRD with abundant croplands. With the estimated emissions 38 % smaller in E2, the average of simulated NH3 concentrations with an air quality model using E2 was 27 % smaller than that using E1 at two ground sites in the YRD. At the suburban site in Pudong, Shanghai (SHPD), the simulated NH3 concentrations with E1 were generally larger than observations, and the modeling performance was improved, indicated by the smaller normalized mean errors (NMEs) when E2 was applied. In contrast, very limited improvement was found at the urban site JSPAES, as E2 failed to improve the emission estimation of transportation and residential activities. Compared to NH3, the modeling performance for inorganic aerosols was better for most cases, and the differences between the simulated concentrations with E1 and E2 were clearly smaller, at 7 %, 3 %, and 12 % (relative to E1) for NH4+, SO42-, and NO3-, respectively. Compared to the satellite-derived NH3 column, application of E2 significantly corrected the overestimation in vertical column density for January and October with E1, but it did not improve the model performance for July. The NH3 emissions might be underestimated with the assumption of linear correlation between NH3 volatilization and soil pH for acidic soil, particularly in warm seasons. Three additional cases, i.e., 40 % abatement of SO2, 40 % abatement of NOx, and 40 % abatement of both species, were applied to test the sensitivity of NH3 and inorganic aerosol concentrations to precursor emissions. Under an NH3-rich condition, estimation of SO2 emissions was detected to be more effective on simulation of secondary inorganic aerosols compared to NH3. Reduced SO2 would restrain the formation of (NH4)2SO4 and thereby enhance the NH3 concentrations. To improve the air quality more effectively and efficiently, NH3 emissions should be substantially controlled along with SO2 and NOx in the future.

Air quality and its response to satellite-derived urban form in the Yangtze River Delta, China

2017 ◽  
Vol 75 ◽  
pp. 297-306 ◽  
Author(s):  
Qiannan She ◽  
Xia Peng ◽  
Qian Xu ◽  
Lingbo Long ◽  
Ning Wei ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Form ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
The Yangtze River Delta

scholarly journals Quantification and evaluation of atmospheric ammonia emissions with different methods: A case study for the Yangtze River Delta region, China

2019 ◽  
Author(s):  
Yu Zhao ◽  
Mengchen Yuan ◽  
Xin Huang ◽  
Feng Chen ◽  
Jie Zhang
Keyword(s):  
Air Quality ◽  
Yangtze River ◽  
Satellite Observation ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
Nh3 Volatilization ◽  
Inorganic Aerosols ◽  
Emission Estimation ◽  
The Yangtze River Delta

Abstract. To explore the effects of data and method on emission estimation, two inventories of NH3 emissions of the Yangtze River Delta (YRD) region in eastern China were developed for 2014 based on the constant emission factors (E1) and those characterizing the agricultural processes (E2), respectively. The latter integrated the detailed information of soil, meteorology and agricultural processes, and derived the monthly information of emission factors and activity data. The total emissions were calculated at 1765 and 1067 Gg, respectively, and agricultural activities (livestock farming and fertilizer use) were estimated to contribute 74–84 % to total emissions in the two inventories. Clear differences existed in seasonal and spatial distributions of NH3 emissions. Elevated emissions were found in March and September in E2, attributed largely to the increased top dressing fertilization and to the enhanced NH3 volatilization under high temperature, respectively. Relatively large discrepancy between the methods existed in northern Yangtze River Delta areas with abundant croplands. The two inventories were evaluated through air quality modeling and available ground and satellite observation. With the estimated emissions 38 % smaller in E2, the average of simulated NH3 concentrations using E2 was 27 % smaller than that using E1 at two ground observation sites in the YRD region. At the suburban SHPD site, the simulated NH3 concentrations with E1 were generally larger than observation, and the modeling performance was largely improved indicated by the smaller NMEs when E2 was applied. In contrast, very limited improvement was found at the urban site JSPAES, as E2 failed to improve the emission estimation of local sources including transportation and residential activities. Compared to NH3, the modeling performance for inorganic aerosols was better for most cases, and the differences between the simulated concentrations with E1 and E2 were clearly smaller, at 7 %, 3 % and 12 % (relative to E1) for NH4+, SO42−, and NO3−, respectively. Regarding the satellite-derived NH3 column, application of E2 significantly corrected the overestimation in vertical column density simulation for January and October with E1, but did not improve the model performance for July. The NH3 emissions might be underestimated with the assumption of linear correlation between NH3 volatilization and soil pH for acidic soil, particularly in warm seasons. Three additional cases, i.e., 40 % abatement of SO2, 40 % abatement of NOX, and 40 % abatement of both species were applied to test the sensitivity of NH3 and inorganic aerosol concentrations to precursor emissions. Under an NH3-rich condition for most of YRD, estimation of SO2 emissions was detected to be more effective on simulation of secondary inorganic aerosols compared to NH3. Reduced SO2 would restrain the formation of (NH4)2SO4, and thereby enhance the NH3 concentrations. Besides the emissions, uncertainties existed as well in the limitations of ground and satellite observation and incomplete mechanism of gas to particle conversion applied in the model. To improve the air quality more effectively and efficiently, NH3 emissions should be substantially controlled along with SO2 and NOX in the future.

Sign in / Sign up

Export Citation Format

Share Document