Numerical analysis of the impact of anthropogenic emissions on the urban environment of Singapore

Author(s):  
Vivek Kumar Singh ◽  
M.O. Mughal ◽  
Alberto Martilli ◽  
Juan A. Acero ◽  
Jordan Ivanchev ◽  
...  
Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 707
Author(s):  
Petros Vasilakos ◽  
Yongtao Hu ◽  
Armistead Russell ◽  
Athanasios Nenes

Formation of aerosol from biogenic hydrocarbons relies heavily on anthropogenic emissions since they control the availability of species such as sulfate and nitrate, and through them, aerosol acidity (pH). To elucidate the role that acidity and emissions play in regulating Secondary Organic Aerosol (SOA), we utilize the 2013 Southern Oxidant and Aerosol Study (SOAS) dataset to enhance the extensive mechanism of isoprene epoxydiol (IEPOX)-mediated SOA formation implemented in the Community Multiscale Air Quality (CMAQ) model (Pye et al., 2013), which was then used to investigate the impact of potential future emission controls on IEPOX OA. We found that the Henry’s law coefficient for IEPOX was the most impactful parameter that controls aqueous isoprene OA products, and a value of 1.9 × 107 M atm−1 provides the best agreement with measurements. Non-volatile cations (NVCs) were found in higher-than-expected quantities in CMAQ and exerted a significant influence on IEPOX OA by reducing its production by as much as 30% when present. Consistent with previous literature, a strong correlation of isoprene OA with sulfate, and little correlation with acidity or liquid water content, was found. Future reductions in SO2 emissions are found to not affect this correlation and generally act to increase the sensitivity of IEPOX OA to sulfate, even in extreme cases.


2018 ◽  
Vol 373 (1760) ◽  
pp. 20170301 ◽  
Author(s):  
Richard A. Betts ◽  
Chris D. Jones ◽  
Jeff. R. Knight ◽  
Ralph. F. Keeling ◽  
John. J. Kennedy ◽  
...  

In early 2016, we predicted that the annual rise in carbon dioxide concentration at Mauna Loa would be the largest on record. Our forecast used a statistical relationship between observed and forecast sea surface temperatures in the Niño 3.4 region and the annual CO 2 rise. Here, we provide a formal verification of that forecast. The observed rise of 3.4 ppm relative to 2015 was within the forecast range of 3.15 ± 0.53 ppm, so the prediction was successful. A global terrestrial biosphere model supports the expectation that the El Niño weakened the tropical land carbon sink. We estimate that the El Niño contributed approximately 25% to the record rise in CO 2 , with 75% due to anthropogenic emissions. The 2015/2016 CO 2 rise was greater than that following the previous large El Niño in 1997/1998, because anthropogenic emissions had increased. We had also correctly predicted that 2016 would be the first year with monthly mean CO 2 above 400 ppm all year round. We now estimate that atmospheric CO 2 at Mauna Loa would have remained above 400 ppm all year round in 2016 even if the El Niño had not occurred, contrary to our previous expectations based on a simple extrapolation of previous trends. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’.


2013 ◽  
Vol 30 (05) ◽  
pp. 1350020 ◽  
Author(s):  
ZHUPING LIU ◽  
QIUHONG ZHAO ◽  
SHOUYANG WANG ◽  
JIANMING SHI

This paper investigates the impact of partial information sharing in a three-echelon supply chain. Partial information sharing means that information sharing occurs only between the distributor and the retailer, but not between the distributor and the manufacturer. This paper contributes to the literature by summarizing the circumstances in which information sharing between the retailer and the distributor benefits the manufacturer. In addition, our study points out that such information sharing does not always bring benefits to the manufacturer and that in some cases the information sharing may harm the manufacturer. We explain the reasons why this can happen and give managerial intuition for our results. Using numerical analysis, we illustrate the impact of partial information sharing on the agents in the supply chain with the change of the autoregressive coefficient in the demand process.


Author(s):  
Ken FURUDOI ◽  
Shigeki SAKAI ◽  
Kazuo MURAKAMI ◽  
Yoshiyuki NAKAMURA ◽  
Ikuo ABE ◽  
...  

Author(s):  
O de Rincón ◽  
M Sánchez ◽  
V Millano ◽  
R de Gutiérrez ◽  
J Maldonado ◽  
...  
Keyword(s):  

2020 ◽  
Vol 2 (5) ◽  
pp. 19-24
Author(s):  
P. Evdokimov

the article describes the problems of assessing the anthropogenic impact of human activity on natural com-plexes surrounding urbanized territories. Among the main research tasks are development of methodological foundations for assessing the quanti-tative and qualitative composition at anthropogenic impact on natural complexes surrounding urban areas. The main method of this research include a dialectical approach that focuses on generally accepted logi-cal research methods (analysis, systematic approach, generalization) and their synthesis using relevant in-formation materials. The author considered various methods of assessing the impact of various factors on the environment, and also carried out the examination of urban decisions related to the appointment of a category (status) the natural resources included in the urban environment in Moscow. The Russian capital is a European metropolis, the largest city-millionaire in Europe and a typical object of research to identify the effects of various anthropogenic factors. The implementation at economic activity in the metropolis is accompanied by the emergence of problems, the solution of which has not been found yet. Analysis of methods for assessing the impact at the various factors on the environment was carried out taking into account the provisions in regulatory documents governing the appointment for protected areas urban environment. Provisions of regulatory documents and decisions of executive authorities designed to use natural (forest) resources in urban environments. The absence of approved methods for assessing certain types of land plots with a protected status was identified. The main factors affecting the quality of biogeocenosis were identified. The main features of the applica-tion methods for assessing the status and possibility in recreational development in territories of varying de-grees at development are considered.


The quality of surface water remains an important issue today. This is particularly acute for water bodies located in the urban-basin geosystems. Purpose. To estimate pressure of atmospheric precipitation within the urban landscape basin geosystem on the river water (by example of the Kharkiv river). Methods. Field landscaping, ecological, landscape-geochemical; analytical; system analysis; chemical analytical; statistical Results. An assessment of the state of surface waters under the impact from the surface runoff of atmospheric origin during 2014-2016, and partly from 2017-2019, formed under the influence of the transport (partly residential) subsystem of the urban area and surface waters in Kharkiv. On the salt content, the characteristic of water quality is "moderately polluted" (1,6); on the tropho-saprobiological indicators, the quality of water is characterized as "polluted" (from 3.1 to 2.75 along the river). It is in this context the impact of waters, which is formed in the conditions of the urban environment for the quality of natural waters, is well demonstrated. The presence of high values of pollutants and natural factors. The assessment of the quality of water on the content of specific indicators is "moderately polluted" (from 2.28 to 1.85). Conclusions. The water of the Kharkiv region, which has a strong influence from the urban environment, has a grade III quality; the water is "moderately polluted". Environmental assessment indicates the impact of surface runoff already on the middle part of the river, which increases in accordance with the conditions of the operation of urban landscapes and anthropogenic (transport) load.


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