Annual lamination and its sedimentary implications in the Yangtze River delta inferred from High-resolution biogenic silica and sensitive grain-size records

2011 ◽  
Vol 31 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Dejiang Fan ◽  
Hongyan Qi ◽  
Xiaoxia Sun ◽  
Yong Liu ◽  
Zuosheng Yang
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Biogenic Silica ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
The Yangtze 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 East Asian monsoon during the past 10,000 years recorded by grain size of Yangtze River delta

2021 ◽  
Vol 13 (1) ◽  
pp. 505-516
Author(s):  
Xiaohui Wang ◽  
Longsheng Wang ◽  
Shouyun Hu ◽  
Ge Yu ◽  
Qing Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Yangtze River ◽  
Asian Monsoon ◽  
Environmental Changes ◽  
East Asian Monsoon ◽  
East Asian ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
The Yangtze River Delta

Abstract Paleoenvironmental research is critical for understanding delta evolution processes and managing delta sustainability, particularly for delta experiencing significant recent fluvial sediment discharge. Based on other previously reported optically stimulated luminescence (OSL) data, Holocene environmental changes of the Yangtze River delta in response to climate fluctuations and human activities were reviewed on the basis of grain-size analyses of core YZ07. The results of grain-size and end-member analysis (EMA) provide a detailed history of East Asian monsoon variability and environmental changes since ∼10,000 cal year B.P. The lower median values (Md) and sand content reflect relatively cool and dry climate conditions between 10,000 and 9,570 cal year B.P. During the early Holocene (9,570–7,630 cal year B.P.), the highest Md values and sand contents and the lowest end member 2 (EM2) contents suggest the Holocene transgression. The increased Md values and sand contents indicate that the climate conditions were warm and wet during the mid-Holocene thermal optimum. From 4,690 to 4,150 cal year B.P., the climate was cool and dry, corresponding to the cool event, as indicated by the finer grain size. Subsequently, between 4,150 and 2,850 cal year B.P., the grain size derived from the Md value and sand content increased, which reflect a wet and warm episode. The climate, which shifted from warm and wet to cool and dry between 2,850 and 1,020 cal year B.P., may have caused a reduction in the sand contents and Md values. After 1,020 cal year B.P., the lowest values of Md and Standard deviation (Sd) and the highest contents of EM2 and clay suggest that the Yangtze River delta has been severely affected by anthropogenic activity. The variability of the East Asian monsoon intensity in the Yangtze River delta strongly correlates with other East Asian monsoon paleoclimate records in China. These results are important for investigations into the interactions between regional systems and global change in monsoonal climatic regions and can provide an example of the evolution of a large scale geomorphic feature resulting from river-sea interaction.

Quartz grain characteristics of the late Pleistocene hard clay in the Yangtze River delta and implications for sedimentary environment and provenance

2020 ◽  
Vol 97 ◽  
pp. 199-215
Author(s):  
Chao Wu ◽  
Peng Qian ◽  
Xiangmin Zheng ◽  
Limin Zhou ◽  
Hui Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Late Pleistocene ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
The Yrd ◽  
The Yangtze River Delta ◽  
Quartz Grains ◽  
Scanning Electron

AbstractThe sedimentologic fingerprinting in detrital deposit is vital to reconstruct sedimentary environments and discriminate sources. In this study, grain size and microtextural characteristics of quartz from the late Pleistocene hard clay in the Yangtze River delta (YRD) were analyzed by using a laser particle size analyzer and a scanning electron microscope. Subaqueous quartz from the Yangtze River and Yellow River sediments and eolian quartz from the Chinese Loess Plateau loess were also analyzed by scanning electron microscopy to obtain the microtextural characteristics. Quartz grains of the hard clay were characterized by poor sorting, fine skew, bimodal grain-size distributions, and numerous eolian microtextures. The comparison of the quartz grain characteristics of the hard clay with these in eolian loess indicated that the hard clay belonged to an eolian deposition. Moreover, the fine quartz grains of the hard clay were dominated by eolian microtextural characteristics, representing long-distance transportation. The coarse quartz grains of the hard clay exhibited more subaqueous microtextural characteristics, which indicated that the coarse fraction of the hard clay was derived from the proximal source regions in the YRD. The determination of buried eolian deposition with multiple sources in the YRD implies a southward westerly jet stream, strengthened eolian dust transportation, and extensive aridification in the YRD due to the increased Northern Hemisphere ice sheets in Marine Oxygen Isotope Stage 2.

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.

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

High-resolution anthropogenic ammonia emission inventory for the Yangtze River Delta, China

Chemosphere ◽  
2020 ◽  
Vol 251 ◽  
pp. 126342 ◽  
Author(s):  
Xingna Yu ◽  
Li Shen ◽  
Xinhong Hou ◽  
Liang Yuan ◽  
Yuepeng Pan ◽  
...  
Keyword(s):  
High Resolution ◽  
Yangtze River ◽  
Emission Inventory ◽  
Yangtze River Delta ◽  
River Delta ◽  
Ammonia Emission ◽  
The Yangtze River ◽  
The Yangtze River Delta
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