scholarly journals Diurnal and Seasonal Variations of Carbon Dioxide (CO2) Concentration in Urban, Suburban, and Rural Areas around Tokyo

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 367 ◽  
Author(s):  
Ryoichi Imasu ◽  
Yuka Tanabe

Site environments and instrumental characteristics of carbon dioxide (CO2) measurements operated by local governments in the Kanto Plain, the center of which is Tokyo, were summarized for this study. The observation sites were classified into environments of three types: urban, suburban, and woodland. Based on a few decades of accumulated hourly data, the diurnal and seasonal variations of CO2 concentrations were analyzed as a composite of anomalies from annual means recorded for each site. In urban areas, the highest concentrations appear before midnight in winter. The second peak corresponds to the morning rush hour and the strengthening of the inversion layer. Suburban areas can be characterized as having the highest concentration before dawn and the lowest concentration during the daytime in summer in association with the activation of respiration and photosynthesis of vegetation. In these areas, concentration peaks also appear during the morning rush hour. Woodland areas show background features, with the highest concentration in early spring, which are higher than the global background by about 5 ppmv.

Author(s):  
Ryoichi Imasu ◽  
Yuka Tanabe

Site environments and instrumental characteristics of carbon dioxide (CO2) measurements operated by local governments in the Kanto Plain, the center of which is Tokyo were summarized for this study. The observation sites were classified into environments of three types: urban, suburban, and woodland. Based on a few decades of accumulated hourly data, the diurnal and seasonal variations of CO2 concentrations were analyzed as a composite of anomalies from annual means recorded for each site. In urban areas, the highest concentrations appear before midnight in winter. The second peak corresponds to the morning rush hour and strengthening of the inversion layer. Suburban areas can be characterized as having the highest concentration before dawn and the lowest concentration during the daytime in summer in association with the activation of respiration and photosynthesis of vegetation. In these areas, concentration peaks also appear during the morning rush hour. Woodland areas show background features, with the highest concentration in early spring: higher than the global background by about 5 ppmv.


2019 ◽  
Author(s):  
Kamau Wright ◽  
Robert Galvez

Abstract Simulations and experiments are conducted to model, simulate, test and demonstrate the effect of plasma discharges on decomposition of carbon dioxide (CO2). A pin-to-plane discharge is employed in gas samples containing CO2. A high voltage plasma system is used which was previously shown to be able to decrease CO2 concentration in gas samples. The discharge is modeled and described, including monitoring electrical parameters such as current and voltage. The present study investigated plasma decomposition of carbon dioxide experimentally, and through simulation. A plasma micro-discharge was utilized to better understand plasma-CO2 interactions. Enhancements are suggested to help increase the efficiency and yield of the plasma-CO2 decomposition process. Gas samples are analyzed over time using a CO2 meter.


2017 ◽  
Vol 10 (2) ◽  
pp. 667-680 ◽  
Author(s):  
Shohei Nomura ◽  
Hitoshi Mukai ◽  
Yukio Terao ◽  
Toshinobu Machida ◽  
Yukihiro Nojiri

Abstract. We developed a battery-powered carbon dioxide (CO2) measurement system for monitoring at the summit of Mt. Fuji (3776 m a.s.l.), which experiences very low temperatures (below −20 °C) and severe environmental conditions without access to gridded electricity for 10 months (from September to June). Our measurement system used 100 batteries to run the measurement unit during these months. These batteries were charged during the 2-month summer season when gridded electricity was available, using a specially designed automatic battery-charging system. We installed this system in summer 2009 at the Mt. Fuji weather station; observations of atmospheric CO2 concentration were taken through December 2015. Measurements were never interrupted by a lack of battery power except for two cases in which lightning damaged a control board. Thus we obtained CO2 data during about 94 % of the 6-year period. Analytical performances (stability and accuracy) were better than 0.1 ppm, as tested by checking working standards and comparisons with flask sampling.Observational results showed that CO2 mole fractions at Mt. Fuji demonstrated clear seasonal variation. The trend and the variability of the CO2 growth rate observed at Mt. Fuji were very similar to those of the Mauna Loa Observatory (MLO). Seasonally, the concentration at Mt. Fuji was 2–10 ppm lower in summer and 2–12 ppm higher in winter than those at MLO. The lower concentrations at Mt. Fuji in summer are mainly attributed to episodes of air mass transport from Siberia or China, where CO2 is taken up by the terrestrial biosphere. On the other hand, the relatively higher concentrations in winter seem to reflect the high percentage of air masses originating from China or Southeast Asia during this period, which carry increased anthropogenic carbon dioxide. These results show that Mt. Fuji is not very influenced by local sources but rather by the sources and sinks over a very large region.Thus we conclude that, as this system could provide stable measurement data with relatively easy operation for 6 years at Mt. Fuji, it could be a useful monitoring technique for remote background sites elsewhere.


Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1373
Author(s):  
Amir Izzuddin Adnan ◽  
Mei Yin Ong ◽  
Saifuddin Nomanbhay ◽  
Pau Loke Show

Carbon dioxide is the most influential gas in greenhouse gasses and its amount in the atmosphere reached 412 µmol/mol in August 2020, which increased rapidly, by 48%, from preindustrial levels. A brand-new chemical industry, namely organic chemistry and catalysis science, must be developed with carbon dioxide (CO2) as the source of carbon. Nowadays, many techniques are available for controlling and removing carbon dioxide in different chemical processes. Since the utilization of CO2 as feedstock for a chemical commodity is of relevance today, this study will focus on how to increase CO2 solubility in culture media used for growing microbes. In this work, the CO2 solubility in a different medium was investigated. Sodium hydroxide (NaOH) and monoethanolamine (MEA) were added to the culture media (3.0 g/L dipotassium phosphate (K2HPO4), 0.2 g/L magnesium chloride (MgCl2), 0.2 g/L calcium chloride (CaCl2), and 1.0 g/L sodium chloride (NaCl)) for growing microbes in order to observe the difference in CO2 solubility. Factors of temperature and pressure were also studied. The determination of CO2 concentration in the solution was measured by gas analyzer. The result obtained from optimization revealed a maximum CO2 concentration of 19.029 mol/L in the culture media with MEA, at a pressure of 136.728 kPa, operating at 20.483 °C.


2019 ◽  
Vol 9 (2) ◽  
pp. 209
Author(s):  
Anselem C. Nweke

This paper examines the implication of rural- urban migration on Nigeria Society using Anambra state as focus of the study. Cities have been growing both through natural increase and through stampede from rural areas in Nigeria. People migrate to urban areas based on the prevailing conditions they fund themselves and the reasons for the migration vary from one individual to another depending on the situation that informs the decision to migrate. In most rural areas, the effect of rural-urban migration was a rapid deterioration of the rural economy leading to poverty and food scarcity. The cause of the phenomenon has been described as the push factors in the rural areas and the pull factors in the urban areas. The objective of this paper is to identify the implication of rural-urban migration on Nigeria society. It is a survey research. Thus, 1200 questionnaire were distributed among the selected local governments in Anambra State. The analysis was run using Runs test and mode analysis. The result of the analysis found the effect of people migrating from rural areas to urban centres on the society to include: increase in prostitution in the urban centres; increase in squalor settlement in the urban centres; and people are doing all sorts of odd jobs in order to survive in urban centres. The paper therefore recommends that the government should make and implement a policy on provision of functional social amenities such as electricity, pipe borne water etc. in the rural areas. Good schools and qualified teachers should be made available in the rural areas and establishment of industries in both rural and urban areas that will to an extent accommodate unemployed youths.


2016 ◽  
Vol 56 (1) ◽  
pp. 108 ◽  
Author(s):  
Mei Bai ◽  
David W. T. Griffith ◽  
Frances A. Phillips ◽  
Travis Naylor ◽  
Stephanie K. Muir ◽  
...  

Accurate measurements of methane (CH4) emissions from feedlot cattle are required for verifying greenhouse gas (GHG) accounting and mitigation strategies. We investigate a new method for estimating CH4 emissions by examining the correlation between CH4 and carbon dioxide (CO2) concentrations from two beef cattle feedlots in Australia representing southern temperate and northern subtropical locations. Concentrations of CH4 and CO2 were measured at the two feedlots during summer and winter, using open-path Fourier transform infrared spectroscopy. There was a strong correlation for the concentrations above background of CH4 and CO2 with concentration ratios of 0.008 to 0.044 ppm/ppm (R2 >0.90). The CH4/CO2 concentration ratio varied with animal diet and ambient temperature. The CH4/CO2 concentration ratio provides an alternative method to estimate CH4 emissions from feedlots when combined with CO2 production derived from metabolisable energy or heat production.


2017 ◽  
Vol 68 (9) ◽  
pp. 1585 ◽  
Author(s):  
Stephen R. Midway ◽  
Caleb T. Hasler ◽  
Tyler Wagner ◽  
Cory D. Suski

Carbon dioxide (CO2) in fresh-water environments is poorly understood, yet in marine environments CO2 can affect fish behaviour, including predator–prey relationships. To examine changes in predator success in elevated CO2, we experimented with predatory Micropterus salmoides and Pimephales promelas prey. We used a two-factor fully crossed experimental design; one factor was 4-day (acclimation) CO2 concentration and the second factor CO2 concentration during 20-min predation experiments. Both factors had three treatment levels, including ambient partial pressure of CO2 (pCO2; 0–1000 μatm), low pCO2 (4000–5000 μatm) and high pCO2 (8000–10000 μatm). Micropterus salmoides was exposed to both factors, whereas P. promelas was not exposed to the acclimation factor. In total, 83 of the 96P. promelas were consumed (n=96 trials) and we saw no discernible effect of CO2 on predator success or time to predation. Failed strikes and time between failed strikes were too infrequent to model. Compared with marine systems, our findings are unique in that we not only saw no changes in prey capture success with increasing CO2, but we also used CO2 treatments that were substantially higher than those in past experiments. Our work demonstrated a pronounced resiliency of freshwater predators to elevated CO2 exposure, and a starting point for future work in this area.


Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6436
Author(s):  
Mai Hu ◽  
Bing Chen ◽  
Lu Yao ◽  
Chenguang Yang ◽  
Xiang Chen ◽  
...  

Research on carbon dioxide (CO2) geological and biogeochemical cycles in the ocean is important to support the geoscience study. Continuous in-situ measurement of dissolved CO2 is critically needed. However, the time and spatial resolution are being restricted due to the challenges of very high submarine pressure and quite low efficiency in water-gas separation, which, therefore, are emerging the main barriers to deep sea investigation. We develop a fiber-integrated sensor based on cavity ring-down spectroscopy for in-situ CO2 measurement. Furthermore, a fast concentration retrieval model using exponential fit is proposed at non-equilibrium condition. The in-situ dissolved CO2 measurement achieves 10 times faster than conventional methods, where an equilibrium condition is needed. As a proof of principle, near-coast in-situ CO2 measurement was implemented in Sanya City, Haina, China, obtaining an effective dissolved CO2 concentration of ~950 ppm. The experimental results prove the feasibly for fast dissolved gas measurement, which would benefit the ocean investigation with more detailed scientific data.


2021 ◽  
Vol 5 (1) ◽  
pp. p65
Author(s):  
R. Vardanjans ◽  
L. Cirule

Preterm neonates often have to spend a long time in incubator which simulates necessary enviromental conditions to maintain patients in stable condition. Authors have found neglected problem with Carbon Dioxide (CO2) concentration in newborn inhaled gas when using “oxygen hood” into infant incubator that has not been studied very closely. Methods in this experiement were carried out as condition monitoring while changing some parameters and positions. Results have shown that CO2 level is letally high in some aspects. Situation is alarming as CO2 level in incubator is not limited by current regulation, as IEC60601-2-19: 2009 +A1:2016. Currently the Incubator manufacturers declare that CO2 maximal concentration should be periodically checked by users, which are hospitals. Some commercially available incubators have the maximum allowed CO2 level 8000 ppm, which is much higher than recommended 2000 ppm CO2 level in indoor working place. There is no limitation of maximal level of CO2 using “oxygen hood”, which are specified in incubator operation manual. This paper goal is to show the correlation of CO2 level versus gas flow into oxygen hood.


2021 ◽  
Vol 10 (1) ◽  
pp. 53
Author(s):  
Septianto Aldiansyah

Kendari City is the capital of Southeast Sulawesi Province with a population of 345,110 people. The number of residents can trigger a narrowing of RTH (RTH) due to meeting the need for land over time. RTH in urban areas ideally is 30% of the total area with 20% public RTH and 10% private RTH. This study aims for RTH based on the comparison of the area of the RTH Regional Spatial Plan (RTRW) and the actual RTH, the population, the ability to produce oxygen (O2) and absorption of carbon dioxide (CO2) in the actual RTH. This research uses quantitative descriptive research in evaluating RTH. The results showed that public RTH in the RTRW still lacked 6.93% so that it was still necessary to review the RTRW to meet these needs. The current RTH is also still less than the minimum standard of RTH in Kendari City of 7.01% in public RTH. If it is accumulated, the current availability of RTH still does not meet the minimum standard of RTH in Kendari City. The availability of oxygen (O2) and absorption of carbon dioxide (CO2) in Kendari City can still meet the needs of residents in Kendari City.


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