Reconstruction of high-resolution magnetostratigraphy of the Changjiang (Yangtze) River Delta, China

2015 ◽  
Vol 204 (2) ◽  
pp. 948-960 ◽  
Author(s):  
Zongqi Duan ◽  
Qingsong Liu ◽  
Xuefa Shi ◽  
Zhengquan Yao ◽  
Jianxing Liu ◽  
...  
Keyword(s):  
High Resolution ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta

scholarly journals High resolution modeling of gaseous methylamines over a polluted region in China: Source-dependent emissions and implications to spatial variations

2018 ◽  
Author(s):  
Jingbo Mao ◽  
Fangqun Yu ◽  
Yan Zhang ◽  
Jingyu An ◽  
Lin Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Yangtze River ◽  
Regional Scale ◽  
Yangtze River Delta ◽  
River Delta ◽  
Urban Site ◽  
The Yangtze River ◽  
Delta Region ◽  
Yangtze River Delta Region ◽  
The Yangtze River Delta

Abstract. Amines have received increasing attention in recent years because of their potential role in new particle formation in the atmosphere and their impact on aerosol chemistry. High concentrations of amines are expected to be limited to the vicinity of source regions due to their short lifetime, highlighting the necessity of having a better understanding of contributions of emissions from different source types. This study presents the first high-resolution model simulation of methylamines concentrations on a regional scale over the Yangtze River Delta region in east China. The WRF-Chem with nested grids is used in model simulations. In contrast to the very limited existing modeling studies that assumed a fixed ratio (FR) of amines to total ammonia emission, we derive source-dependent ratios (SDR) that distinguish C1-amine (CH3NH2), C2-amines (C2H7N), C3-amines (C3H9N) emissions from five different source types (agriculture, residential, transportation, chemical industry, and other industry). The amines-to-ammonia mass emission ratios, estimated from previous measurements, are 0.026, 0.0015, 0.0011, 0.0011, and 0.0011 for C1-amine, 0.007, 0.0018, 0.0015, 0.01, and 0.0009 for C2-amines, and 0.0004, 0.0005, 0.00043, 0.0006, and 0.0004 for C3-amines for chemical-industrial, other industrial, agricultural, residential, and transportational sources, respectively. The simulated concentrations of C1-, C2-, and C3-amines, based on both FR and SDR, have been compared with field measurements at a suburban site in Nanjing and at an urban site in Shanghai, China. SDR substantially improves the model’s ability in capturing the observed concentrations of methylamines. C1-, C2-, and C3-amines concentrations in the surface layer in the Yangtze River Delta region are generally in the range of 2–20 pptv, 5–50 pptv, and 0.5–4 pptv. Vertically, the concentrations of C1-, C2-, and C3-amines decrease quickly with altitude, dropping by a factor of ~ 10 from the surface to ~ 900 hPa. Results from the present study are critical to evaluating potential roles of amines in nucleation and chemical processes in polluted air.

scholarly journals High-resolution (0.05° × 0.05°) NO<sub><i>x</i></sub> emissions in the Yangtze River Delta inferred from OMI

2019 ◽  
Author(s):  
Hao Kong ◽  
Jintai Lin ◽  
Ruixiong Zhang ◽  
Mengyao Liu ◽  
Hongjian Weng ◽  
...  
Keyword(s):  
High Resolution ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
Inversion Method ◽  
Fine Scale ◽  
The Yangtze River ◽  
Monitoring Instrument ◽  
The Yrd ◽  
The Yangtze River Delta

Abstract. Emission datasets of nitrogen oxides (NOx) at high horizontal resolutions (e.g., 0.05° × 0.05°) are crucial for understanding human influences at fine scales, air quality studies, and pollution control. Yet high-resolution emission data are often lacking or contain large uncertainties especially for the developing regions. Taking advantage of long-term satellite measurements of nitrogen dioxide (NO2), here we develop a computationally efficient method to inverting NOx emissions in major urban areas at the 0.05° × 0.05° resolution. The inversion accounts for the nonlinear effects of horizontal transport, chemical loss, and deposition. We construct a 2-dimensional Peking University High-resolution Lifetime-Emission-Transport (PHLET) model, its adjoint model (PHLET-A), and a Satellite Conversion Metrix approach to relate emissions, simulated NO2, and satellite NO2 data. The inversion method is applied to summer months of 2012–2016 in the Yangtze River Delta area (YRD, 118 °E–123 °E, 29 °N–34 °N), a major polluted region of China, using the POMINO NO2 vertical column density product retrieved from the Ozone Monitoring Instrument. A systematic analysis of inversion errors is performed, including using an Observing System Simulation Experiment-like test. Across the YRD area, the inverted summer average emission ranges from 0 to 12.0 kg km−2 h−1, and the lifetime (due to chemical loss and deposition) from 1.4 to 3.6 h. Our inverted emission dataset reveals fine-scale spatial information tied to nighttime light, population density, road network, and maritime shipping. Many of the inverted fine-scale emission features are not well represented or not included in the widely used Multi-scale Emissions Inventory of China. Our inversion method can be applied to other regions and other satellite sensors such as the TROPOspheric Monitoring Instrument.

scholarly journals Quantitative Analysis on Coastline Changes of Yangtze River Delta Based on High Spatial Resolution Remote Sensing Images

2022 ◽  
Vol 14 (2) ◽  
pp. 310
Author(s):  
Qi Wu ◽  
Shiqi Miao ◽  
Haili Huang ◽  
Mao Guo ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Spatial Resolution ◽  
Yangtze River ◽  
High Spatial Resolution ◽  
Yangtze River Delta ◽  
River Delta ◽  
Coastal Zones ◽  
Spatial Coverage ◽  
The Yrd

The coastline situation reflects socioeconomic development and ecological environment in coastal zones. Analyzing coastline changes clarifies the current coastline situation and provides a scientific basis for making environmental protection policies, especially for coastlines with significant human interference. As human activities become more intense, coastline types and their dynamic changes become more complicated, which needs more detailed identification of coastlines. High spatial resolution images can help provide detailed large spatial coverage at high resolution information on coastal zones. This study aims to map the position and status of the Yangtze River Delta (YRD) coastline using an NDWI threshold method based on 2 m Gaofen-1/Ziyuan-3 imagery and analyze coastline change and coastline type distribution characteristics. The results showed that natural and artificial coastlines in the YRD region accounted for 42.73% and 57.27% in 2013 and 41.56% and 58.44% in 2018, respectively. The coastline generally advanced towards the sea, causing a land area increase of 475.62 km2. The changes in the YRD coastline mainly resulted from a combination of large-scale artificial construction and natural factors such as silt deposition. This study provides a reference source for large spatial coverage at high resolution remote sensing coastline monitoring and a better understanding of land use in coastal zone.

Full-coverage high-resolution daily PM2.5 estimation using MAIAC AOD in the Yangtze River Delta of China

2017 ◽  
Vol 199 ◽  
pp. 437-446 ◽  
Author(s):  
Qingyang Xiao ◽  
Yujie Wang ◽  
Howard H. Chang ◽  
Xia Meng ◽  
Guannan Geng ◽  
...  
Keyword(s):  
High Resolution ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
Full Coverage ◽  
The Yangtze River Delta

scholarly journals High-resolution (0.05°  ×  0.05°) NO<sub><i>x</i></sub> emissions in the Yangtze River Delta inferred from OMI

2019 ◽  
Vol 19 (20) ◽  
pp. 12835-12856 ◽  
Author(s):  
Hao Kong ◽  
Jintai Lin ◽  
Ruixiong Zhang ◽  
Mengyao Liu ◽  
Hongjian Weng ◽  
...  
Keyword(s):  
High Resolution ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
Google Earth ◽  
River Delta ◽  
Inversion Method ◽  
Fine Scale ◽  
The Yangtze River ◽  
Peking University ◽  
The Yangtze River Delta

Abstract. Emission datasets of nitrogen oxides (NOx) at high horizontal resolutions (e.g., 0.05∘×0.05∘) are crucial for understanding human influences at fine scales, air quality studies, and pollution control. Yet high-resolution emission data are often missing or contain large uncertainties especially for the developing regions. Taking advantage of long-term satellite measurements of nitrogen dioxide (NO2), here we develop a computationally efficient method of estimating NOx emissions in major urban areas at the 0.05∘×0.05∘ resolution. The top-down inversion method accounts for the nonlinear effects of horizontal transport, chemical loss, and deposition. We construct a two-dimensional Peking University High-resolution Lifetime-Emission-Transport model (PHLET), its adjoint model (PHLET-A), and a satellite conversion matrix approach to relate emissions, lifetimes, simulated NO2, and satellite NO2 data. The inversion method is applied to the summer months of 2012–2015 in the Yangtze River Delta (YRD; 29–34∘ N, 118–123∘ E) area, a major polluted region of China, using the NO2 vertical column density data from the Peking University Ozone Monitoring Instrument NO2 product (POMINO). A systematic analysis of inversion errors is performed, including using an independent test based on GEOS-Chem simulations. Across the YRD area, the summer average emissions obtained in this work range from 0 to 15.3 kg km−2 h−1, and the lifetimes (due to chemical loss and deposition) range from 0.6 to 3.3 h. Our emission dataset reveals fine-scale spatial information related to nighttime light, population density, road network, maritime shipping, and land use (from a Google Earth photo). We further compare our emissions with multiple inventories. Many of the fine-scale emission structures are not well represented or not included in the widely used Multi-scale Emissions Inventory of China (MEIC).

scholarly journals High-resolution modeling of gaseous methylamines over a polluted region in China: source-dependent emissions and implications of spatial variations

2018 ◽  
Vol 18 (11) ◽  
pp. 7933-7950 ◽  
Author(s):  
Jingbo Mao ◽  
Fangqun Yu ◽  
Yan Zhang ◽  
Jingyu An ◽  
Lin Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Yangtze River ◽  
Regional Scale ◽  
Yangtze River Delta ◽  
River Delta ◽  
Urban Site ◽  
The Yangtze River ◽  
Delta Region ◽  
Yangtze River Delta Region ◽  
The Yangtze River Delta

Abstract. Amines have received increasing attention in recent years because of their potential role in new particle formation in the atmosphere and their impact on aerosol chemistry. High concentrations of amines are expected to be limited to the vicinity of source regions due to their short lifetime, highlighting the necessity of having a better understanding of contributions of emissions from different source types. This study presents the first high-resolution model simulation of concentrations of methylamines on a regional scale over the Yangtze River Delta region in East China. The WRF-Chem with nested grids is used in model simulations. In contrast to the very limited existing modeling studies that assumed a fixed ratio (FR) of amines to total ammonia emission, we derive source-dependent ratios (SDR) that distinguish C1-amine (CH3NH2), C2-amines (C2H7N), C3-amines (C3H9N) emissions from five different source types (agriculture, residential, transportation, chemical industry, and other industry). The amines-to-ammonia mass emission ratios, estimated from previous measurements, are 0.026, 0.0015, 0.0011, 0.0011, and 0.0011 for C1-amine; 0.007, 0.0018, 0.0015, 0.01, and 0.0009 for C2-amines; and 0.0004, 0.0005, 0.00043, 0.0006, and 0.0004 for C3-amines for chemical–industrial, other industrial, agricultural, residential, and transportational sources, respectively. The simulated concentrations of C1-, C2-, and C3-amines, based on both FR and SDR, have been compared with field measurements at a suburban site in Nanjing and at an urban site in Shanghai, China. SDR substantially improves the ability of the model in capturing the observed concentrations of methylamines. Concentrations of C1-, C2-, and C3-amines in the surface layer in the Yangtze River Delta region are generally in the range of 2–20, 5–50, and 0.5–4 pptv. Vertically, the concentrations of C1-, C2-, and C3-amines decrease quickly with altitude, dropping by a factor of ∼10 from the surface to ∼900 hPa. Results from the present study are critical to evaluating potential roles of amines in nucleation and chemical processes in polluted air.

Full-Coverage High-Resolution Daily PM2.5 Estimation using MAIAC AOD in the Yangtze River Delta of China

2018 ◽  
Vol 2017 (1) ◽  
pp. 137
Author(s):  
Qingyang Xiao ◽  
Yang Liu ◽  
Yujie Wang ◽  
Howard H. Chang ◽  
Xia Meng ◽  
...  
Keyword(s):  
High Resolution ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
Full Coverage ◽  
The Yangtze River Delta
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