scholarly journals A Sensitivity Study of the 4.8 µm Carbon Dioxide Absorption Band in the MWIR Spectral Range

2020 ◽  
Vol 12 (1) ◽  
pp. 172 ◽  
Author(s):  
Vito Romaniello ◽  
Claudia Spinetti ◽  
Malvina Silvestri ◽  
Maria Fabrizia Buongiorno
Keyword(s):  
Carbon Dioxide ◽  
Absorption Band ◽  
Strong Dependence ◽  
Point Sources ◽  
Channel Width ◽  
Anthropogenic Sources ◽  
Co2 Absorption ◽  
Industrial Emissions ◽  
Surface Temperatures ◽  
Concentration Changes

The measurements of gas concentrations in the atmosphere are recently developed thanks to the availability of gases absorbing spectral channels in space sensors and strictly depending on the instrument performances. In particular, measuring the sources of carbon dioxide is of high interest to know the distribution, both spatial and vertical, of this greenhouse gas and quantify the natural/anthropogenic sources. The present study aims to understand the sensitivity of the CO2 absorption band at 4.8 µm to possibly detect and measure the spatial distribution of emissions from point sources (i.e., degassing volcanic plumes, fires, and industrial emissions). With the aim to define the characteristics of future multispectral imaging space radiometers, the performance of the CO2 4.8 µm absorption band was investigated. Simulations of the “Top of Atmosphere” (TOA) radiance have been performed by using real input data to reproduce realistic scenarios on a volcanic high elevation point source (>2 km): actual atmospheric background of CO2 (~400 ppm) and vertical atmospheric profiles of pressure, temperature, and humidity obtained from probe balloons. The sensitivity of the channel to the CO2 concentration has been analyzed also varying surface temperatures as environmental conditions from standard to high temperature. Furthermore, response functions of operational imaging sensors in the middle wave infrared spectral region were used. The channel width values of 0.15 µm and 0.30 µm were tested in order to find changes in the gas concentration. Simulations provide results about the sensitivity necessary to appreciate carbon dioxide concentration changes considering a target variation of 10 ppm in gas column concentration. Moreover, the results show the strong dependence of at-sensor radiance on the surface temperature: radiances sharply increase, from 1 Wm−2sr−1µm−1 (in the “standard condition”) to >1200 Wm−2sr−1µm−1 (in the warmest case) when temperatures increase from 300 to 1000 K. The highest sensitivity has been obtained considering the channel width equal to 0.15 µm with noise equivalent delta temperature (NEDT) values in the range from 0.045 to 0.56 K at surface temperatures ranging from 300 to 1000 K.

Sensitivity studies of the 4.8 micron carbon dioxide absorption band for high temperature events

2020 ◽  
Author(s):  
Vito Romaniello ◽  
Claudia Spinetti ◽  
Malvina Silvestri ◽  
Maria Fabrizia Buongiorno
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Absorption Band ◽  
Strong Dependence ◽  
Standard Condition ◽  
Channel Width ◽  
Transfer Model ◽  
Industrial Emissions ◽  
Surface Temperatures ◽  
Concentration Changes

<p>Measuring the sources of carbon dioxide is of high interest in order to know the distribution of this greenhouse gas and quantify the natural/anthropogenic emissions. The aim of the present study is to understand the capability of the absorption band at 4.8 µm to detect and measure the CO<sub>2</sub> emissions from different HTEs (High Temperature Events) like degassing plumes from active volcanic sources, fires and industrial emissions. The performance of this channel was investigated by using the MODTRAN (MODerate resolution atmospheric TRANsmission) radiative transfer model. Simulations of the TOA (Top Of Atmosphere) radiance have been performed by using real input data to reproduce realistic scenarios on a volcanic high elevation point source (>2 km). The sensitivity of the channel has been analysed varying CO<sub>2</sub> concentrations (in the range 0-1000 ppm) and surface temperatures from standard (300 K) to high temperature (1000 K). Moreover, typical response functions of imaging sensors carried on aircraft and operating in the Middle Wave InfraRed (MWIR) spectral region were used: the channel width values of 0.15 µm and 0.30 µm were tested. Simulations provide results about the sensitivity necessary to appreciate carbon dioxide concentration changes considering a target variation of 10 ppm in the gas column concentration. The results show the strong dependence of at-sensor radiance on the surface temperature: radiances sharply increase, from 1 Wm<sup>-2</sup>sr<sup>-1</sup>µm<sup>-1</sup> (in the standard condition) to >1200 Wm<sup>-2</sup>sr<sup>-1</sup>µm<sup>-1</sup> (in the warmest case). The highest sensitivity has been obtained considering the channel width equal to 0.15 µm with noise equivalent delta temperature (NEDT) values in the range from 0.045 to 0.560 K at surface temperatures ranging from 300 to 1000 K. Furthermore, data acquired by the multispectral MASTER (Modis ASTER) airborne simulator on Kilauea volcano (Hawaii), during the January/February 2018 campaign, were considered. The aim is to estimate lava flow/lake temperatures and to test the channel at 4.8 µm for retrieving CO<sub>2</sub> emissions on volcanic craters.</p>

scholarly journals CO2 Retrieval over Clouds from the OCO Mission: Model Simulations and Error Analysis

2009 ◽  
Vol 26 (6) ◽  
pp. 1090-1104 ◽  
Author(s):  
Jérôme Vidot ◽  
Ralf Bennartz ◽  
Christopher W. O’Dell ◽  
René Preusker ◽  
Rasmus Lindstrot ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Absorption Band ◽  
Liquid Water ◽  
Spectral Characteristics ◽  
Optimal Estimation ◽  
High Spectral Resolution ◽  
Oxygen Absorption ◽  
Co2 Absorption ◽  
Mixing Ratio ◽  
Cloud Properties

Abstract Spectral characteristics of the future Orbiting Carbon Observatory (OCO) sensor, which will be launched in January 2009, were used to infer the carbon dioxide column-averaged mixing ratio over liquid water clouds over ocean by means of radiative transfer simulations and an inversion process based on optimal estimation theory. Before retrieving the carbon dioxide column-averaged mixing ratio over clouds, cloud properties such as cloud optical depth, cloud effective radius, and cloud-top pressure must be known. Cloud properties were not included in the prior in the inversion but are retrieved within the algorithm. The high spectral resolution of the OCO bands in the oxygen absorption spectral region around 0.76 μm, the weak CO2 absorption band around 1.61 μm, and the strong CO2 absorption band around 2.06 μm were used. The retrieval of all parameters relied on an optimal estimation technique that allows an objective selection of the channels needed to reach OCO’s requirement accuracy. The errors due to the radiometric noise, uncertainties in temperature profile, surface pressure, spectral shift, and presence of cirrus above the liquid water clouds were quantified. Cirrus clouds and spectral shifts are the major sources of errors in the retrieval. An accurate spectral characterization of the OCO bands and an effective mask for pixels contaminated by cirrus would mostly eliminate these errors.

scholarly journals Multi-Oxygenated Organic Compounds in Fine Particulate Matter Collected in the Western Mediterranean Area

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 94
Author(s):  
Esther Borrás ◽  
Luis Antonio Tortajada-Genaro ◽  
Francisco Sanz ◽  
Amalia Muñoz
Keyword(s):  
Particulate Matter ◽  
Carboxylic Acids ◽  
Organic Compounds ◽  
Organic Pollutants ◽  
Mediterranean Area ◽  
Western Mediterranean ◽  
Anthropogenic Sources ◽  
Gas Chromatography Mass Spectrometry ◽  
Industrial Emissions ◽  
Tetradecanoic Acid

The chemical characterization of aerosols, especially fine organic fraction, is a relevant atmospheric challenge because their composition highly depends on localization. Herein, we studied the concentration of multi-oxygenated organic compounds in the western Mediterranean area, focusing on sources and the effect of air patterns. The organic aerosol fraction ranged 3–22% of the total organic mass in particulate matter (PM)2.5. Seventy multi-oxygenated organic pollutants were identified by gas chromatography–mass spectrometry, including n-alkanones, n-alcohols, anhydrosugars, monocarboxylic acids, dicarboxylic acids, and keto-derivatives. The highest concentrations were found for carboxylic acids, such as linoleic acid, tetradecanoic acid and, palmitic acid. Biomarkers for vegetation sources, such as levoglucosan and some fatty acids were detected at most locations. In addition, carboxylic acids from anthropogenic sources—mainly traffic and cooking—have been identified. The results indicate that the organic PM fraction in this region is formed mainly from biogenic pollutants, emitted directly by vegetation, and from the degradation products of anthropogenic and biogenic volatile organic pollutants. Moreover, the chemical profile suggested that this area is interesting for aerosol studies because several processes such as local costal breezes, industrial emissions, and desert intrusions affect fine PM composition.

scholarly journals Czech Building Stock: Renovation Wave Scenarios and Potential for CO2 Savings until 2050

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2455
Author(s):  
Antonín Lupíšek ◽  
Tomáš Trubačík ◽  
Petr Holub
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Climate Change Mitigation ◽  
Emission Factors ◽  
Anthropogenic Sources ◽  
Building Stock ◽  
National Debate ◽  
Energy Consumptions ◽  
Change Mitigation

One of the major anthropogenic sources of greenhouse gases is the operation of building stock. Improving its energy efficiency has the potential to significantly contribute to achieving climate change mitigation targets. The purpose of this study was to roughly estimate such potential for the operation of the national building stock of Czechia to steer the national debate on the development of related national plans. The estimation is based on a simplified energy model of the Czech building stock that consists of sub-models of residential and nonresidential building stocks, for which their future energy consumptions, shares of energy carriers and sources, and emission factors were modeled in four scenarios. Uncertainties from the approximation of the emission factors were investigated in a sensitivity analysis. The results showed that the operation of the Czech building stock in 2016 totaled 36.9 Mt CO2, which represented 34.6% of the total national carbon dioxide emissions. The four building stock scenarios could produce reductions in the carbon dioxide emissions of between 28% and 93% by 2050, when also considering on-side production from photovoltaics. The implementation of the most ambitious scenario would represent a drop in national CO2 yearly emissions by 43.2% by 2050 (compared to 2016).

scholarly journals Assessment of carbon dioxide separation by amine solutions using electrolyte non-random two-liquid and Peng-Robinson models: Carbon dioxide absorption efficiency

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Arash Esmaeili ◽  
◽  
Zhibang Liu ◽  
Yang Xiang ◽  
Jimmy Yun ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Co2 Concentration ◽  
Liquid Hydrocarbon ◽  
Absorption Efficiency ◽  
High Reactivity ◽  
Proper Solution ◽  
Co2 Absorption ◽  
Carbon Dioxide Absorption ◽  
Operational Conditions ◽  
Wide Range

A high pressure carbon dioxide (CO2) absorption from a specific gas in a conventional column has been evaluated by the Aspen HYSYS simulator using a wide range of single absorbents and blended solutions to estimate the outlet CO2 concentration, absorption efficiency and CO2 loading to choose the most proper solution in terms of CO2 capture for environmental concerns. The property package (Acid Gas-Chemical Solvent) which is compatible with all applied solutions for the simulation in this study, estimates the properties based on an electrolyte non-random two-liquid (E- NRTL) model for electrolyte thermodynamics and Peng-Robinson equation of state for the vapor and liquid hydrocarbon phases. Among all the investigated single amines as well as blended solutions, piperazine (PZ) and the mixture of piperazine and monoethanolamine (MEA) have been found as the most effective absorbents respectively for CO2 absorption with high reactivity based on the simulated operational conditions.

Quantifying the contribution of regional methane emissions to the global methane budget between 2008 and 2018 using the TOMCAT chemical transport model

2021 ◽  
Author(s):  
Emily Dowd ◽  
Christopher Wilson ◽  
Martyn Chipperfield ◽  
Manuel Gloor
Keyword(s):  
Carbon Dioxide ◽  
Land Surface ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Transport Model ◽  
Chemical Transport ◽  
Methane Emissions ◽  
Anthropogenic Sources ◽  
Chemical Transport Model ◽  
Methane Budget

<p>Methane (CH<sub>4</sub>) is the second most important atmospheric greenhouse gas after carbon dioxide. Global concentrations of CH<sub>4</sub> have been rising in the last decade and our understanding of what is driving the increase remains incomplete. Natural sources, such as wetlands, contribute to the uncertainty of the methane budget. However, anthropogenic sources, such as fossil fuels, present an opportunity to mitigate the human contribution to climate change on a relatively short timescale, since CH<sub>4</sub> has a much shorter lifetime than carbon dioxide. Therefore, it is important to know the relative contributions of these sources in different regions.</p><p>We have investigated the inter-annual variation (IAV) and rising trend of CH<sub>4</sub> concentrations using a global 3-D chemical transport model, TOMCAT. We independently tagged several regional natural and anthropogenic CH<sub>4</sub> tracers in TOMCAT to identify their contribution to the atmospheric CH<sub>4</sub> concentrations over the period 2009 – 2018. The tagged regions were selected based on the land surface types and the predominant flux sector within each region and include subcontinental regions, such as tropical South America, boreal regions and anthropogenic regions such as Europe. We used surface CH<sub>4</sub> fluxes derived from a previous TOMCAT-based atmospheric inversion study (Wilson et al., 2020). These atmospheric inversions were constrained by satellite and surface flask observations of CH<sub>4</sub>, giving optimised monthly estimates for fossil fuel and non-fossil fuel emissions on a 5.6° horizontal grid. During the study period, the total optimised CH<sub>4</sub> flux grew from 552 Tg/yr to 593 Tg/yr. This increase in emissions, particularly in the tropics, contributed to the increase in atmospheric CH<sub>4 </sub>concentrations and added to the imbalance in the CH<sub>4</sub> budget. We will use the results of the regional tagged tracers to quantify the contribution of regional methane emissions at surface observation sites, and to quantify the contributions of the natural and anthropogenic emissions from the tagged regions to the IAV and the rising methane concentrations.</p><p>Wilson, C., Chipperfield, M. P., Gloor, M., Parker, R. J., Boesch, H., McNorton, J., Gatti, L. V., Miller, J. B., Basso, L. S., and Monks, S. A.: Large and increasing methane emissions from Eastern Amazonia derived from satellite data, 2010–2018, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1136, in review, 2020.</p>

Distinguishing human related, biological, and geological carbon dioxide in the air through isotopic surveying

2021 ◽  
Author(s):  
Giorgio Capasso ◽  
Roberto M.R. Di Martino ◽  
Antonio Caracausi ◽  
Rocco Favara
Keyword(s):  
Carbon Dioxide ◽  
Source Identification ◽  
Isotope Composition ◽  
Strong Dependence ◽  
Landfill Gas ◽  
Molar Fraction ◽  
Data Interpretation ◽  
Isotopic Signature ◽  
Atmospheric Sciences ◽  
Gas Source

<p>Stable isotopes have several applications in geosciences and specifically in volcanology, fluids vs earthquakes studies, environmental surveying, and atmospheric sciences. Both geological and human-related gas sources emit carbon dioxide promoting its molar fraction increase in the lower levels of the atmosphere. The strong dependence of global warming from the carbon dioxide (CO<sub>2</sub>) concentration in the air promoted the detailed investigation of the sources of CO<sub>2</sub>. Land use inspection and the correlated increase of air CO<sub>2</sub> concentration proved often the potential identification of the gas sources. Both the precise identification of the gas source and the specific contribution are still open challenges in environmental surveying. Isotopic signature allows both source identification and tracking fate of carbon dioxide (i.e. natural degassing in volcanic and active tectonic regions, photosynthetic fractionation in tree forests, and human-related emissions in urban zones). The isotopic signature allows evaluating the environmental impact of specific actions and better addressing the mitigation efforts by tracking fate of CO<sub>2</sub>.</p><p>This study aims to identify the CO<sub>2</sub> sources in different ecosystems by using a laser spectrometer that allowed to determine rapidly and with high precision the isotope composition of CO<sub>2</sub> in the space and/or at high frequency (up to 1Hz). Various environments include both volcanic, seismic and urban zones because of their strong effects on the low levels of the atmosphere were considered, showing how this kind of instruments can disclose new horizons, in many different applications and especially in the time domain. In the considered zones, both the anthropogenic and geological sources caused the increases of CO<sub>2</sub> molar fraction in the last few centuries. Suitable case studies were: i) the air CO<sub>2</sub> surveying at Palermo; ii) the soil CO<sub>2</sub> emissions at Vulcano (Aeolian Islands - Italy), and iii) the punctual vent CO<sub>2</sub> emissions at Umbertide (Perugia - Italy).</p><p>The results of this study show detailed investigation of both sources and fate of the CO<sub>2</sub> in various environments. The results of the isotope surveying in Palermo show that air CO<sub>2</sub> correlated with human activities (i.e. house heating, urban mobility, and landfill gas emissions). Comparison with air CO<sub>2</sub> at Umbertide shows the greater contribution of the geogenic reservoir near the active fault of Alto Tiberina Valley. Volcanic CO<sub>2</sub> distinguished from biological CO<sub>2</sub> by different isotopic signature in the soil gases of Vulcano. The soil CO<sub>2</sub> partitioning at the settled zone of Vulcano Porto occurred through both gas source identification and data interpretation through a specifically designed isotopic mixing model.</p><p>This study provides several innovative experimental solutions that are suitable to understand the complexity of carbon cycle and unexplored so far environmental scenarios.</p>

scholarly journals A study on CO2 absorption using hybrid solvents in packed columns

2019 ◽  
Author(s):  
Ravinder Kumar ◽  
Mohammad Hossein Ahmadi ◽  
Dipen Kumar Rajak ◽  
Mohammad Alhuyi Nazari
Keyword(s):  
Carbon Dioxide ◽  
Co2 Capture ◽  
Power Plants ◽  
Large Scale ◽  
Carbon Dioxide Capture ◽  
Packed Column ◽  
Absorption Efficiency ◽  
Co2 Absorption ◽  
Process Industries ◽  
Carbon Dioxide Co2

Abstract Greenhouse gases emissions from large scale industries as well as gasoline based vehicles are mainly responsible for global warming since the 1980s. At present, it has triggered global efforts to reduce the level of GHG. The contribution of carbon dioxide (CO2) in polluting the environment is at a peak due to the excessive use of coal in power plants. So, serious attention is required to reduce the level of CO2 using advanced technologies. Carbon dioxide capture and storage may play an important role in this direction. In process industries, various carbon dioxide capture techniques can be used to reduce CO2 emissions. However, post-combustion carbon dioxide capture is on top priority. Nowadays the researcher is focusing their work on CO2 capture using hybrid solvent. This work highlights a review of carbon dioxide capture using various kind of hybrid solvent in a packed column. The various challenges for absorption efficiency enhancement and future direction are also discussed in the present work. It is concluded through the literature survey that hybrid solvent shows better efficiency in comparison to the aqueous solution used for CO2 capture.

scholarly journals Chemical Composition and Source Apportionment of PM2.5 in Urban Areas of Xiangtan, Central South China

2019 ◽  
Vol 16 (4) ◽  
pp. 539 ◽  
Author(s):  
Xiaoyao Ma ◽  
Zhenghui Xiao ◽  
Lizhi He ◽  
Zongbo Shi ◽  
Yunjiang Cao ◽  
...  
Keyword(s):  
Source Apportionment ◽  
South China ◽  
Urban Areas ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Vehicle Exhaust ◽  
Industrial Emissions ◽  
Wind Speeds

Xiangtan, South China, is characterized by year-round high relative humidity and very low wind speeds. To assess levels of PM2.5, daily samples were collected from 2016 to 2017 at two urban sites. The mass concentrations of PM2.5 were in the range of 30–217 µg/m3, with the highest concentrations in winter and the lowest in spring. Major water-soluble ions (WSIIs) and total carbon (TC) accounted for 58–59% and 21–24% of the PM2.5 mass, respectively. Secondary inorganic ions (SO42−, NO3−, and NH4+) dominated the WSIIs and accounted for 73% and 74% at the two sites. The concentrations of K, Fe, Al, Sb, Ca, Zn, Mg, Pb, Ba, As, and Mn in the PM2.5 at the two sites were higher than 40 ng/m3, and decreased in the order of winter > autumn > spring. Enrichment factor analysis indicates that Co, Cu, Zn, As, Se, Cd, Sb, Tl, and Pb mainly originates from anthropogenic sources. Source apportionment analysis showed that secondary inorganic aerosols, vehicle exhaust, coal combustion and secondary aerosols, fugitive dust, industrial emissions, steel industry are the major sources of PM2.5, contributing 25–27%, 21–22%, 19–21%, 16–18%, 6–9%, and 8–9% to PM2.5 mass.

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