Column-integrated aerosol optical properties and direct radiative forcing over the urban-industrial megacity Nanjing in the Yangtze River Delta, China

2016 ◽  
Vol 23 (17) ◽  
pp. 17532-17552 ◽  
Author(s):  
Na Kang ◽  
K. Raghavendra Kumar ◽  
Xingna Yu ◽  
Yan Yin
Keyword(s):  
Optical Properties ◽  
Radiative Forcing ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
Aerosol Optical Properties ◽  
Direct Radiative Forcing ◽  
The Yangtze River Delta

scholarly journals Column and Surface Aerosol Optical Properties and Their Association with Meteorology in the Yangtze River Delta

2019 ◽  
Vol 8 (4) ◽  
pp. 8255-8259
Keyword(s):  
Optical Properties ◽  
Yangtze River ◽  
Negative Relationship ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
Negative Effect ◽  
The Yrd ◽  
The Impact ◽  
The Yangtze River Delta

Aerosols played an important role in climate change during recent years in China. Many kinds of researches in different areas in China, particularly over the Yangtze River Delta (YRD) region in East China is measured during the period from January 2013 to December 2015. The Moderate Resolution Imaging Spectroradiometer (MODIS) derived aerosol optical depth (AOD), particulate matter concentrations (PM2.5) and surface black carbon (BCS) was used in this study. Nanjing, Hangzhou, Shanghai, and Ningbo have been selected in this research as they are the major cities of the YRD region that represents different environments. Variation of AOD550, Ångström exponent (AE470-660) and PM2.5 are mainly discussed, and meanwhile, the relationship that exists between them and with the meteorology is also discussed in this work. Apart from this, the impact of visibility and water vapor are also considered to examine the influence on optical properties. The data and analysis indicate that urban cities have a higher value of AOD than rural background cities. High AOD was noticed in summer than in other seasons. AOD usually has a negative relationship with AE, except in summer. Similarly, the PM2.5 has a negative relationship with AOD, whereas, BCS has a positive correlation with AOD. Further, it was observed that the rise in temperature resulted in high AOD concentration. The visibility has negative effect on AOD, whereas, AQI follows similar pattern as that of visibility.

scholarly journals Aerosol optical properties and instantaneous radiative forcing based on high temporospatial resolution CARSNET ground-based measurements over eastern China

2017 ◽  
Author(s):  
Huizheng Che ◽  
Bing Qi ◽  
Hujia Zhao ◽  
Xiangao Xia ◽  
Philippe Goloub ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Yangtze River ◽  
Eastern China ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
Delta Region ◽  
Yangtze River Delta Region ◽  
Fine Mode ◽  
The Yangtze River Delta

Abstract. Variations in the optical properties of aerosols and their radiative forcing were investigated based on long-term synchronous observations made at three-minute intervals from 2011 to 2015 over seven adjacent CARSNET (China Aerosol Remote Sensing NETwork) urban (Hangzhou), suburban (Xiaoshan, Fuyang, LinAn, Tonglu, Jiande) and rural (ChunAn) stations in the Yangtze River Delta region, eastern China. The aerosol optical depth (AOD) varied from 0.68 to 0.76, with two peaks in June and September, and decreased from the eastern coast to western inland areas. The ratio of the AOD of fine-mode particles to the total AOD was > 0.90 and the extinction Angström exponent was > 1.20 throughout the year at all seven sites. The Moderate Resolution Imaging Spectroradiometer (MODIS) C6 retrieval AOD was validated by comparison with ground-based observations. The correlation coefficients (R2) between the MODIS C6 AOD data and the values measured on the ground were ~ 0.73–0.89. The single-scattering albedo varied from 0.91 to 0.94, indicating that scattering aerosol particles are dominant in this region. The real parts of the refractive index were ~ 1.41–1.43, with no significant difference among the seven urban, suburban and rural sites. Large imaginary parts of the refractive index were seen in August at all urban, suburban and rural sites. The fine-mode radii in the Yangtze River Delta region were ~ 0.2–0.3 μm with a volume of 0.10–0.12 μm3 and the coarse-mode radii were ~ 2.0 μm with a volume close to 0.07 μm3. The fine-mode aerosols were obviously larger in June and September than in other months at almost the sites. The absorption AOD was low in the winter. The absorption Angström exponent and the extinction Angström exponent were used to classify the different types of aerosol and the components of mixtures. The aerosols caused negative radiative forcing both at the Earth's surface and at the top of the atmosphere all year round in the Yangtze River Delta region of eastern China.

scholarly journals Current Status and Temporal Trend of Potentially Toxic Elements Pollution in Agricultural Soil in the Yangtze River Delta Region: A Meta-Analysis

2021 ◽  
Vol 18 (3) ◽  
pp. 1033
Author(s):  
Shufeng She ◽  
Bifeng Hu ◽  
Xianglin Zhang ◽  
Shuai Shao ◽  
Yefeng Jiang ◽  
...  
Keyword(s):  
Yangtze River ◽  
Agricultural Soil ◽  
Toxic Elements ◽  
Temporal Trend ◽  
Meta Analysis ◽  
Yangtze River Delta ◽  
Potentially Toxic Elements ◽  
River Delta ◽  
The Yangtze River ◽  
The Yangtze River Delta

Potentially toxic elements (PTEs) pollution in the agricultural soil of China, especially in developed regions such as the Yangtze River Delta (YRD) in eastern China, has received increasing attention. However, there are few studies on the long-term assessment of soil pollution by PTEs over large regions. Therefore, in this study, a meta-analysis was conducted to evaluate the current state and temporal trend of PTEs pollution in the agricultural land of the Yangtze River Delta. Based on a review of 118 studies published between 1993 and 2020, the average concentrations of Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni were found to be 0.25 mg kg−1, 0.14 mg kg−1, 8.14 mg kg−1, 32.32 mg kg−1, 68.84 mg kg−1, 32.58 mg kg−1, 92.35 mg kg−1, and 29.30 mg kg−1, respectively. Among these elements, only Cd and Hg showed significant accumulation compared with their background values. The eastern Yangtze River Delta showed a relatively high ecological risk due to intensive industrial activities. The contents of Cd, Pb, and Zn in soil showed an increasing trend from 1993 to 2000 and then showed a decreasing trend. The results obtained from this study will provide guidance for the prevention and control of soil pollution in the Yangtze River Delta.

scholarly journals The Evolution of the Interactive Relationship between Urbanization and Land-Use Transition: A Case Study of the Yangtze River Delta

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 804
Author(s):  
Bo Niu ◽  
Dazhuan Ge ◽  
Rui Yan ◽  
Yingyi Ma ◽  
Dongqi Sun ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
Socioeconomic Factor ◽  
The Yangtze River ◽  
Land Use Transition ◽  
The Yangtze River Delta ◽  
Interaction Relationship

In recent years, the impact of land-use systems on global climate change has become increasingly significant, and land-use change has become a hot issue of concern to academics, both within China and abroad. Urbanization, as an important socioeconomic factor, plays a vital role in promoting land-use transition, which also shows a significant spatial dependence on urbanization. This paper constructs a theoretical framework for the interaction relationship between urbanization and land-use transition, taking the Yangtze River Delta as an example, and measures the level of urbanization from the perspective of population urbanization, economic urbanization and social urbanization, while also evaluating the level of land-use morphologies from the perspective of dominant and recessive morphologies of land-use. We construct a PVAR model and coupled coordination model based on the calculated indexes for empirical analysis. The results show that the relationship between urbanization and land-use transition is not a simple linear relationship, but tends to be complex with the process of urbanization, and reasonable urbanization and land-use morphologies will promote further benign coupling in the system. By analyzing the interaction relationship between urbanization and land-use transition, this study enriches the study of land-use change and provides new pathways for thinking about how to promote high-quality urbanization.

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