scholarly journals Quantification of CO<sub>2</sub> and CH<sub>4</sub> emissions over Sacramento, California, based on divergence theorem using aircraft measurements

2019 ◽  
Vol 12 (5) ◽  
pp. 2949-2966 ◽  
Author(s):  
Ju-Mee Ryoo ◽  
Laura T. Iraci ◽  
Tomoaki Tanaka ◽  
Josette E. Marrero ◽  
Emma L. Yates ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Greenhouse Gas ◽  
Greenhouse Gas Emission ◽  
Sampling Strategy ◽  
Divergence Theorem ◽  
Emission Sources ◽  
Flight Pattern ◽  
Factors Affecting ◽  
Emission Fluxes ◽  
Emission Estimate

Abstract. Emission estimates of carbon dioxide (CO2) and methane (CH4) and the meteorological factors affecting them are investigated over Sacramento, California, using an aircraft equipped with a cavity ring-down greenhouse gas sensor as part of the Alpha Jet Atmospheric eXperiment (AJAX) project. To better constrain the emission fluxes, we designed flights in a cylindrical pattern and computed the emission fluxes from two flights using a kriging method and Gauss's divergence theorem. Differences in wind treatment and assumptions about background concentrations affect the emission estimates by a factor of 1.5 to 7. The uncertainty is also impacted by meteorological conditions and distance from the emission sources. The vertical layer averaging affects the flux estimate, but the choice of raw wind or mass-balanced wind is more important than the thickness of the vertical averaging for mass-balanced wind for both urban and local scales. The importance of vertical mass transfer for flux estimates is examined, and the difference in the total emission estimate with and without vertical mass transfer is found to be small, especially at the local scale. The total flux estimates accounting for the entire circumference are larger than those based solely on measurements made in the downwind region. This indicates that a closed-shape flight profile can better contain total emissions relative to a one-sided curtain flight because most cities have more than one point source and wind direction can change with time and altitude. To reduce the uncertainty of the emission estimate, it is important that the sampling strategy account not only for known source locations but also possible unidentified sources around the city. Our results highlight that aircraft-based measurements using a closed-shape flight pattern are an efficient and useful strategy for identifying emission sources and estimating local- and city-scale greenhouse gas emission fluxes.

scholarly journals Quantification of CO<sub>2</sub> and CH<sub>4</sub> emissions over Sacramento, California based on divergence theorem using aircraft measurements

2018 ◽  
Author(s):  
Ju-Mee Ryoo ◽  
Laura T. Iraci ◽  
Tomoaki Tanaka ◽  
Josette E. Marrero ◽  
Emma L. Yates ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Greenhouse Gas ◽  
Greenhouse Gas Emission ◽  
Divergence Theorem ◽  
Flight Pattern ◽  
Factors Affecting ◽  
Mixing Ratios ◽  
Emission Fluxes ◽  
Carbon Dioxide Co2 ◽  
Modeling Strategy

Abstract. Emission estimates of carbon dioxide (CO2) and methane (CH4) and the meteorological factors affecting them are investigated over Sacramento, California, using an aircraft equipped with a cavity ring–down greenhouse gas sensor as part of the Alpha Jet Atmospheric eXperiment (AJAX) project. To better constrain the emissions fluxes, we designed flights in a cylindrical pattern and computed the emission fluxes from three flights using a kriging method and Gauss's divergence theorem. The CO2 and CH4 mixing ratios at the downwind side of Sacramento show relatively consistent patterns across the three flights, but the fluxes vary – as a function of different wind patterns on a given flight day. The wind variability, seasonality, and assumptions about background concentrations affect the emissions estimates, by a factor of 1.5 to 8. The uncertainty is also impacted by meteorological conditions and distance from the emissions sources. The largest CH4 mixing ratio was found over a local landfill. The importance of vertical mass transfer for flux estimates is examined, but the difference in the total emission estimate with and without vertical mass transfer is found to be small, especially at the local scale. The total flux estimates accounting for the entire circumference are larger than those based solely on the downwind region. This indicates that a closed-shape flight profile can better contain total emissions relative to one-sided curtain flight because most cities have more than one point source and wind direction can change with time and altitude. To reduce the uncertainty of the emissions estimate, it is important that the sampling and modeling strategy account not only for known source locations but also possible unidentified sources around the city. Our results highlight that aircraft-based measurements using a closed shape flight pattern are an efficient and useful strategy for identifying emission sources and estimating local and city-scale greenhouse gas emission fluxes.

scholarly journals Greenhouse gas emission fluxes from peat bogs in the Arak Lake Basin in 2021

2021 ◽  
Vol 937 (2) ◽  
pp. 022035
Author(s):  
Hang Cui
Keyword(s):  
Greenhouse Gas ◽  
Greenhouse Gas Emission ◽  
Growing Season ◽  
Peat Bogs ◽  
Lake Basin ◽  
Emission Flux ◽  
Ch4 Emission ◽  
Chromatography Method ◽  
Climatic Fluctuations ◽  
Emission Fluxes

Abstract Climate change has an important impact on greenhouse gas emissions from wetland ecosystems. The static box-meteorological chromatography method was used to determine the CO2 and CH4 emission fluxes of hummocky and hollow in the peat bogs in the Arak Lake Basin during the growing season in 2021. The results showed that the peaks of the CO2 and CH4 emission fluxes in the growing seasons of the hummocky and hollow appeared in July, and their value in May is the lowest. The average C02 emission flux (376.39±56.14 mg-m-2-h-1) during the growing season of hummocky is higher than that of hollow (167.36 mg-m-2-h-1), while the average emission flux of CH4 during the growing season of hummocky (2.00±0.31 mg-m-2-h-1) is lower than that of hollow (3.04 mg-m-2-h-1). The climatic fluctuations have caused differences in the CO2 and CH4 emission fluxes of the same micro-topography in the study area during the growing season between 2020 and 2021.

Barrier Factors Affecting Adoption of Green Building Technologies in Nigeria

2020 ◽  
Vol 17 (2) ◽  
pp. 37
Author(s):  
Amuda-Yusuf Ganiyu ◽  
Raheem Wasiu Mayowa ◽  
Adebiyi Ranti Taibat ◽  
Abdulraheem Maimunat Orire ◽  
Idris Soliu ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Greenhouse Gas ◽  
Greenhouse Gas Emission ◽  
Green Building ◽  
Relevant Information ◽  
Analysis Model ◽  
Green Products ◽  
Factors Affecting ◽  
Lack Of Information ◽  
Level Of Significance

Greenhouse gas emission from activities in the built environment is increasing exponentially due to increase in building operations. This study aims at determining factors that affect adoption of Green Building Technologies that normally reduce greenhouse gas emissions. To elicit relevant information, online structured questionnaire forms were administered on practitioners who have been involved in green building development in Nigeria. Mean score ranking was adopted in ranking the barriers to green building technologies, while discriminant analysis was performed to examine how organizations groups (client, consulting, contracting, academia) were distinguished on the barrier factors identified. Findings revealed that, out of the 23 barrier factors considered in this research, lack of institutions to formulate policies and set guidelines (mean score - 4.5) ranked 1st as barrier to adoption of green building technologies in Nigeria. This is closely followed by lack of information about green products (4.0), low level of awareness about sustainability issues (4.0), human resource and client knowledge, lack of knowledge about green building technologies, high cost of green products, while unavailability of sustainable materials and products ranked the lowest (2.7). Only nine factors at 0.05 level of significance entered the discriminant analysis model and emerged as variables with the most significant power in differentiating the organization groupings on the basis of perceived barriers to adoption of green building technologies. The study recommends that there should be strong political will from government, to establish institutions that formulate policies on green building technologies.Keywords: Barriers, Green Building, Green Building Technologies.

scholarly journals Greenhouse Gas Emission from Rice field in Indonesia: Challenge for future research and development

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Miranti Ariani ◽  
Eko Haryono ◽  
Eko Hanudin
Keyword(s):  
Research And Development ◽  
Greenhouse Gas ◽  
Rice Field ◽  
Greenhouse Gas Emission ◽  
Ghg Emissions ◽  
Interdisciplinary Approach ◽  
Rice Cultivar ◽  
Future Research ◽  
Factors Affecting ◽  
Farming Practice

Rice is an essential crop in Indonesia. Any aspects of rice to increase productivity have been well studied and documented; however, there are still lacking well-documented studies on its environmental aspects, including climate change. Many researches might already be conducted, but only a few have been published in a peer-reviewed journal. There is still a lack of robust data on greenhouse gas (GHG) emissions from the rice field in Indonesia, factors affecting and the technology on how to reduce it. From the reviewed publications, it was found out that research only conducted under a controlled environmental setting. More research on understanding the controlling factors (e.g., water management, rice cultivar, soil types, and fertilizer) of GHG emission from rice field is still needed. The result will introduce a sustainable farming practice,  with low in GHG emissions, high in productivity, simple to apply and generate more income to farmers. This review has identified the gaps for future research and development in Indonesia. The research should meet the need, either national or global strategies. Development of a new farming practice will succeed in the presence of government policies. Therefore an intensive interdisciplinary approach between researcher and other stakeholders should be conducted.

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