The seesaw pattern of PM 2.5 interannual anomalies between Beijing‐Tianjin‐Hebei and Yangtze River Delta across eastern China in winter

2022 ◽  
Author(s):  
Xiaohui Liu ◽  
Bin Zhu ◽  
Tong Zhu ◽  
Hong Liao
Keyword(s):  
Yangtze River ◽  
Eastern China ◽  
Yangtze River Delta ◽  
River Delta ◽  
Pm 2.5

scholarly journals Interpreting the <sup>13</sup>C  ∕ <sup>12</sup>C ratio of carbon dioxide in an urban airshed in the Yangtze River Delta, China

2017 ◽  
Vol 17 (5) ◽  
pp. 3385-3399 ◽  
Author(s):  
Jiaping Xu ◽  
Xuhui Lee ◽  
Wei Xiao ◽  
Chang Cao ◽  
Shoudong Liu ◽  
...  
Keyword(s):  
Mole Fraction ◽  
Yangtze River ◽  
Eastern China ◽  
Yangtze River Delta ◽  
River Delta ◽  
Atmospheric Co2 ◽  
The Tibetan Plateau ◽  
Natural Ecosystems ◽  
Carbon Cycles ◽  
The Yrd

Abstract. Observations of atmospheric CO2 mole fraction and the 13C ∕ 12C ratio (expressed as δ13C) in urban airsheds provide constraints on the roles of anthropogenic and natural sources and sinks in local and regional carbon cycles. In this study, we report observations of these quantities in Nanjing at hourly intervals from March 2013 to August 2015, using a laser-based optical instrument. Nanjing is the second largest city located in the highly industrialized Yangtze River Delta (YRD), eastern China. The mean CO2 mole fraction and δ13C were (439.7 ± 7.5) µmol mol−1 and (−8.48 ± 0.56) ‰ over this observational period. The peak monthly mean δ13C (−7.44 ‰, July 2013) was 0.74 ‰ higher than that observed at Mount Waliguan, a WMO (World Meteorological Organization) baseline site on the Tibetan Plateau and upwind of the YRD region. The highly 13C-enriched signal was partly attributed to the influence of cement production in the region. By applying the Miller–Tans method to nighttime and daytime observations to represent signals from the city of Nanjing and the YRD, respectively, we showed that the 13C ∕ 12C ratio of CO2 sources in the Nanjing municipality was (0.21 ± 0.53) ‰ lower than that in the YRD. Flux partitioning calculations revealed that natural ecosystems in the YRD were a negligibly small source of atmospheric CO2.

scholarly journals Spatial-Temporal Differences and Influencing Factors of Tourism Eco-Efficiency in China’s Three Major Urban Agglomerations Based on the Super-EBM Model

2020 ◽  
Vol 12 (10) ◽  
pp. 4156
Author(s):  
Yiyang Sun ◽  
Guolin Hou ◽  
Zhenfang Huang ◽  
Yi Zhong
Keyword(s):  
Pearl River Delta ◽  
Yangtze River ◽  
Eastern China ◽  
Yangtze River Delta ◽  
Tourism Industry ◽  
External Factors ◽  
River Delta ◽  
Policy Implications ◽  
Pearl River ◽  
Urban Agglomerations

On the background of climate change, studying tourism eco-efficiency of cities is of great significance to promote the green development of tourism. Based on the panel data of the three major urban agglomerations in China’s Yangtze River Delta, Pearl River Delta, and Beijing–Tianjin–Hebei region from 2008 to 2017, this paper constructed an evaluation index system and measured the tourism eco-efficiency of 63 cities by using a hybrid distance model called Super-EBM (epsilon-based measure). We compared the spatial and temporal evolution characteristics of tourism eco-efficiency in the three urban agglomerations. Furthermore, the internal factors influencing tourism eco-efficiency were explored through input–output redundancy, and the external factors were analyzed by a panel regression model. The results indicate that the tourism eco-efficiency of the three urban agglomerations in China generally shows a decreasing-rising-declining trend. Among them, the Yangtze River Delta has the highest eco-efficiency, followed by the Pearl River Delta, and the lowest in the Beijing–Tianjin–Hebei region. Moreover, there is a certain gap within each urban agglomeration. The redundancy input of labor and capital is the main internal cause of low eco-efficiency. Among the external factors, the status of the tourism industry and the level of urbanization have a positive effect on eco-efficiency, while the level of tourism development, technological innovation and investment have a negative impact on it. In the future, we must attach great importance to the development quality and overall benefit value of the tourism industry so as to achieve green and balanced development of the three major urban agglomerations in eastern China. Based on the above conclusions, this paper puts forward targeted policy implications to improve the tourism eco-efficiency of cities.

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 Interpreting the <sup>13</sup>C/<sup>12</sup>C ratio of carbon dioxide in an urban airshed in the Yangtze River Delta, China

2016 ◽  
Author(s):  
Jiaping Xu ◽  
Xuhui Lee ◽  
Wei Xiao ◽  
Chang Cao ◽  
Shoudong Liu ◽  
...  
Keyword(s):  
Yangtze River ◽  
Isotope Composition ◽  
Eastern China ◽  
Molar Fraction ◽  
Yangtze River Delta ◽  
River Delta ◽  
Atmospheric Co2 ◽  
Natural Ecosystems ◽  
Urban Airshed ◽  
The Yrd

Abstract. Observations of atmospheric CO2 molar fraction and its 13C isotope composition (δ13C) in urban airsheds provide constraints on the roles of anthropogenic and natural sources in local and regional C cycles. In this study, we report observations of these quantities in Nanjing at hourly intervals from March 2013 to August 2015 using a laser-based optical instrument. Nanjing is the second largest city located in the highly industrialized Yangtze River Delta (YRD), Eastern China. The mean CO2 molar fraction and 13C were 439.7 ppm and −8.48 ‰ over this observational period. The peak monthly mean δ13C (−7.44 ‰, July 2013) was 1.03 ‰ higher than that observed at the Mauna Loa Observatory. The highly enriched 13C signal was attributed to the influence of cement production in the region. By applying the Keeling plot and the Miller–Tans method to midnight and midday observations, respectively, we showed that the 13C signal of C sources in the Nanjing Municipality was 0.48 ‰ lower than that in the YRD. Flux partitioning calculations revealed that natural ecosystems in the YRD were a negligibly small sink of atmospheric CO2, consistent with the Carbon Tracker inverse modeling result.

Spatio-temporal characteristics of precipitation and dryness/wetness in Yangtze River Delta, eastern China, during 1960–2012

2016 ◽  
Vol 172-173 ◽  
pp. 196-205 ◽  
Author(s):  
Yuefeng Wang ◽  
Youpeng Xu ◽  
Chaogui Lei ◽  
Guang Li ◽  
Longfei Han ◽  
...  
Keyword(s):  
Yangtze River ◽  
Eastern China ◽  
Yangtze River Delta ◽  
River Delta ◽  
Temporal Characteristics ◽  
Spatio Temporal
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