scholarly journals Regional and Urban-Scale Environmental Influences of Oceanic DMS Emissions over Coastal China Seas

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 849 ◽  
Author(s):  
Shanshan Li ◽  
Yan Zhang ◽  
Junri Zhao ◽  
Golam Sarwar ◽  
Shengqian Zhou ◽  
...  
Keyword(s):  
Bohai Sea ◽  
Regional Scale ◽  
The Yellow Sea ◽  
East China ◽  
China Seas ◽  
The East China Sea ◽  
Different Seasons ◽  
Fine Mode ◽  
Atmospheric Sulfur ◽  
Coastal China

Marine biogenic dimethyl sulfide (DMS) is an important natural source of sulfur in the atmosphere, which may play an important role in air quality. In this study, the WRF-CMAQ model is employed to assess the impact of DMS on the atmospheric environment at the regional scale of eastern coastal China and urban scale of Shanghai in 2017. A national scale database of DMS concentration in seawater is established based on the historical DMS measurements in the Yellow Sea, the Bohai Sea and the East China Sea in different seasons during 2009~2017. Results indicate that the sea-to-air emission flux of DMS varies greatly in different seasons, with the highest in summer, followed by spring and autumn, and the lowest in winter. The annual DMS emissions from the Yellow Sea, the Bohai Sea and the East China Sea are 0.008, 0.059, and 0.15 Tg S a−1, respectively. At the regional scale, DMS emissions increase atmospheric sulfur dioxide (SO2) and sulfate (SO42−) concentrations over the East China seas by a maximum of 8% in summer and a minimum of 2% in winter, respectively. At the urban scale, the addition of DMS emissions increase the SO2 and SO42− levels by 2% and 5%, respectively, and reduce ozone (O3) in the air of Shanghai by 1.5%~2.5%. DMS emissions increase fine-mode ammonium particle concentration distribution by 4% and 5%, and fine-mode nss-SO42− concentration distributions by 4% and 9% in the urban and marine air, respectively. Our results indicate that although anthropogenic sources are still the dominant contributor of atmospheric sulfur burden in China, biogenic DMS emissions source cannot be ignored.

scholarly journals Detrital Zircon U-Pb Ages in the East China Seas: Implications for Provenance Analysis and Sediment Budgeting

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 398
Author(s):  
Xiangtong Huang ◽  
Jiaze Song ◽  
Wei Yue ◽  
Zhongbo Wang ◽  
Xi Mei ◽  
...  
Keyword(s):  
East China Sea ◽  
Yellow Sea ◽  
Bohai Sea ◽  
East China ◽  
China Seas ◽  
Provenance Analysis ◽  
The East China Sea ◽  
The Bohai Sea ◽  
China Sea ◽  
Source Regions

Linking marine sinks to potential terrestrial sources is one of most intriguing but challenging aspects of sediment source-to-sink studies. In this study, we analyzed 23 zircon samples (3271 filtered best ages) from surface sediments of the east China seas (ECSs) that cover a large portion of the Bohai Sea, Yellow Sea, East China Sea to part of the northeastern South China Sea. The results of U-Pb age distributions exhibit variable signatures in different seas. The Bohai Sea is characterized by 4 age populations at 203–286 Ma, 383–481 Ma, 1830–1940 Ma and 2480–2548 Ma, whereas the southern Yellow Sea and the East China Sea are featured by 5 age populations at 176–223 Ma, 383–481 Ma, 732–830 Ma, 1830–1940 Ma and 2480–2548 Ma. We propose that the presence or absence of the population of 732–830 Ma in the Yangtze Craton (YC) and the North China Craton (NCC) is a possible geochronological signature to distinguish zircon grains derived from the two source regions. Furthermore, on the basis of multidimensional scaling (MDS), U-Pb ages in the sediments of the Bohai Sea, East China Sea and the Taiwan Strait could be correspondently linked to those of the Yellow River, the Yangtze River and Taiwan rivers. The good linkages support the view that U-Pb age distributions of detrital zircons in the margin seas are mainly controlled by fluvial discharges, and ultimately, by the tectonic history of the corresponding source regions. Using a sediment forward mixing model, we obtained the relative sediment contributions and spatial variations of five most important river discharges in the region. The mixing results suggest that the major rivers in the region, i.e., the Yangtze and the Yellow Rivers, are the dominant sediment contributors to the continental margin, and their mixing coefficients could be used to infer relative sediment budgeting. In addition, spatial variations in mixing coefficient in the East China Sea indicate that sediment mixing and partitioning processes in the marine depositional environment have played a part role in propagating the provenance signals as a result of interaction of oceanic currents and tides. The combined method between provenance analysis and mixing modeling provides a feasible way to appreciate sediment budgeting in the geological past.

scholarly journals Mapping gaseous amines, ammonia, and their particulate counterparts in marine atmospheres of China's marginal seas: Part 2 – spatiotemporal heterogeneity, causes and hypothesis

2021 ◽  
Author(s):  
Yating Gao ◽  
Dihui Chen ◽  
Yanjie Shen ◽  
Yang Gao ◽  
Huiwang Gao ◽  
...  
Keyword(s):  
East China Sea ◽  
Yellow Sea ◽  
Bohai Sea ◽  
Chemical Conversion ◽  
The Yellow Sea ◽  
East China ◽  
Marine Atmosphere ◽  
The East China Sea ◽  
China Sea ◽  
Marginal Seas

Abstract. In this study, spatiotemporal heterogeneities in the concentrations of alkaline gases and their particulate counterparts in the marine atmosphere over China's marginal seas were investigated in terms of causes and chemical conversion during two winter cruise campaigns, using semi-continuous measurements made by an onboard URG-9000D Ambient Ion Monitor-Ion chromatograph (AIM-IC, Thermofisher). During the cruise campaign over the East China Sea on December 27, 2019–January 6, 2020, the concentrations of atmospheric trimethylamine (TMAgas) varied by approximately one order of magnitude, with an average (±standard deviation) of 0.10 ± 0.04 µg m−3. Corresponding means were 0.037 ± 0.011 µg m−3 over the Yellow Sea on 7–16 January 2020 and 0.031 ± 0.009 μg m−3 over the Yellow Sea and the Bohai Sea on 9–22 December 2019. In contrast, the simultaneously observed concentrations of TMA in PM2.5, detected as TMAH+, over the East China Sea were 0.098 ± 0.068 µg m−3 and substantially smaller than 0.28 ± 0.18 μg m−3 over the Yellow Sea and the Bohai Sea on 9–22 December 2019. A significant correlation between TMAgas and particulate TMAH+ was obtained over the East China Sea, but no correlation existed over the Yellow Sea and Bohai Sea. The proportional or disproportional variations in concentrations of TMAgas with particulate TMAH+ over the sea zones were likely attributed to the difference in enrichment of TMAH+ in the sea surface microlayer. In addition, spatiotemporal heterogeneities in concentrations of atmospheric ammonia (NH3gas), atmospheric dimethylamine (DMAgas), and DMA in PM2.5, detected as DMAH+, were also investigated. Case analyses were performed to illustrate the formation and chemical conversion of particulate aminium ions in marine aerosols. Finally, we hypothesized a release of basic gases and particulate counterparts from the ocean to the atmosphere, together with secondary formation of DMAH+ and chemical conversion of TMAH+, in the marine atmosphere.

Distribution and influencing factors of dissolved manganese in the Yellow Sea and the East China Sea

2021 ◽  
pp. 104002
Author(s):  
Yuan Zhang ◽  
Lei Li ◽  
Jingling Ren ◽  
Huijun He ◽  
Ruifeng Zhang ◽  
...  
Keyword(s):  
Influencing Factors ◽  
East China Sea ◽  
Yellow Sea ◽  
The Yellow Sea ◽  
East China ◽  
The East China Sea ◽  
China Sea
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