scholarly journals Remote sensing of volcanic CO<sub>2</sub>, HF, HCl, SO<sub>2</sub>, and BrO in the downwind plume of Mt. Etna

2017 ◽  
Vol 10 (1) ◽  
pp. 1-14 ◽  
Author(s):  
André Butz ◽  
Anna Solvejg Dinger ◽  
Nicole Bobrowski ◽  
Julian Kostinek ◽  
Lukas Fieber ◽  
...  
Keyword(s):  
Remote Sensing ◽  
The Other ◽  
Background Concentration ◽  
Volcanic Gases ◽  
Vertical Column ◽  
Volcanic Plumes ◽  
Mt Etna ◽  
The Fourier Transform ◽  
Carbon Dioxide Co2 ◽  
Shortwave Infrared

Abstract. Remote sensing of the gaseous composition of non-eruptive, passively degassing volcanic plumes can be a tool to gain insight into volcano interior processes. Here, we report on a field study in September 2015 that demonstrates the feasibility of remotely measuring the volcanic enhancements of carbon dioxide (CO2), hydrogen fluoride (HF), hydrogen chloride (HCl), sulfur dioxide (SO2), and bromine monoxide (BrO) in the downwind plume of Mt. Etna using portable and rugged spectroscopic instrumentation. To this end, we operated the Fourier transform spectrometer EM27/SUN for the shortwave-infrared (SWIR) spectral range together with a co-mounted UV spectrometer on a mobile platform in direct-sun view at 5 to 10 km distance from the summit craters. The 3 days reported here cover several plume traverses and a sunrise measurement. For all days, intra-plume HF, HCl, SO2, and BrO vertical column densities (VCDs) were reliably measured exceeding 5  × 1016, 2  × 1017, 5  × 1017, and 1  × 1014 molec cm−2, with an estimated precision of 2.2  × 1015, 1.3  × 1016, 3.6  × 1016, and 1.3  × 1013 molec cm−2, respectively. Given that CO2, unlike the other measured gases, has a large and well-mixed atmospheric background, derivation of volcanic CO2 VCD enhancements (ΔCO2) required compensating for changes in altitude of the observing platform and for background concentration variability. The first challenge was met by simultaneously measuring the overhead oxygen (O2) columns and assuming covariation of O2 and CO2 with altitude. The atmospheric CO2 background was found by identifying background soundings via the co-emitted volcanic gases. The inferred ΔCO2 occasionally exceeded 2  ×  1019 molec cm−2 with an estimated precision of 3.7  ×  1018 molec cm−2 given typical atmospheric background VCDs of 7 to 8  ×  1021 molec cm−2. While the correlations of ΔCO2 with the other measured volcanic gases confirm the detection of volcanic CO2 enhancements, correlations were found of variable significance (R2 ranging between 0.88 and 0.00). The intra-plume VCD ratios ΔCO2 ∕ SO2, SO2 ∕ HF, SO2 ∕ HCl, and SO2 ∕ BrO were in the range 7.1 to 35.4, 5.02 to 21.2, 1.54 to 3.43, and 2.9  ×  103 to 12.5  ×  103, respectively, showing pronounced day-to-day and intra-day variability.

scholarly journals Remote sensing of volcanic CO<sub>2</sub>, HF, HCl, SO<sub>2</sub>, and BrO in the downwind plume of Mt. Etna

2016 ◽  
Author(s):  
André Butz ◽  
Anna Solvejg Dinger ◽  
Nicole Bobrowski ◽  
Julian Kostinek ◽  
Lukas Fieber ◽  
...  
Keyword(s):  
Remote Sensing ◽  
The Other ◽  
Background Concentration ◽  
Volcanic Gases ◽  
Vertical Column ◽  
Volcanic Plumes ◽  
Mt Etna ◽  
The Fourier Transform ◽  
Carbon Dioxide Co2 ◽  
Shortwave Infrared

Abstract. Remote sensing of the gaseous composition of non-eruptive, passively degassing volcanic plumes can be a tool to gain insight into volcano interior processes. Here, we report on a field study in September 2015 that demonstrates the feasibility of remotely measuring the volcanic enhancements of carbon dioxide (CO2), hydrogen fluoride (HF), hydrogen chloride (HCl), sulfur dioxide (SO2), and bromine monoxide (BrO) in the downwind plume of Mt. Etna using portable and rugged spectroscopic instrumentation. To this end, we operated the Fourier Transform Spectrometer EM27/SUN for the shortwave-infrared (SWIR) spectral range together with a co-mounted UV spectrometer on a mobile platform in direct-sun view at 5 to 10 km distance from the summit craters. The three days reported here cover several plume traverses and a sunrise measurement. For all days, intra-plume HF, HCl, SO2, and BrO vertical column densities (VCDs) were reliably measured exceeding 5 × 1016 molec/cm2, 2 × 1017 molec/cm2, 5 × 1017 molec/cm2, and 1 × 1014 molec/cm2, with an estimated precision of 2.2 × 1015 molec/cm2, 1.3 × 1016 molec/cm2, 3.6 × 1016 molec/cm2, and 1.3 × 1013 molec/cm2, respectively. Given that CO2, unlike the other measured gases, has a large and well-mixed atmospheric background, derivation of volcanic CO2 VCD enhancements (ΔCO2) required compensating for changes in altitude of the observing platform and for background concentration variability. The first challenge was met by simultaneously measuring the overhead oxygen (O2) columns and assuming covariation of O2 and CO2 with altitude. The atmospheric CO2 background was found by identifying background soundings via the co-emitted volcanic gases. The inferred ΔCO2 occasionally exceeded 2 × 1019 molec/cm2 with an estimated precision of 3.7 × 1018 molec/cm2 given typical atmospheric background VCDs of 7 to 8 × 1021 molec/cm2. While the correlations of ΔCO2 with the other measured volcanic gases confirm the detection of volcanic CO2 enhancements, correlations were found of variable significance (R2 ranging between 0.88 and 0.00). The intra-plume VCD ratios ΔCO2 / SO2, SO2 / HF, SO2 / HCl, and SO2 / BrO were in the range 7.1 to 35.2, 5.02 to 10.5, 1.54 to 3.43, and 2.9 × 103 to 12.5 × 103, respectively, showing pronounced day-to-day and intra-day variability.

scholarly journals The BrIdge voLcanic LIdar—BILLI: A Review of Data Collection and Processing Techniques in the Italian Most Hazardous Volcanic Areas

2020 ◽  
Vol 10 (18) ◽  
pp. 6402
Author(s):  
Stefano Parracino ◽  
Simone Santoro ◽  
Luca Fiorani ◽  
Marcello Nuvoli ◽  
Giovanni Maio ◽  
...  
Keyword(s):  
Data Collection ◽  
Co2 Flux ◽  
Volcanic Eruptions ◽  
Co2 Concentration ◽  
Volcanic Hazards ◽  
Volcanic Gases ◽  
Volcanic Gas ◽  
Mt Etna ◽  
Carbon Dioxide Co2 ◽  
Processing Techniques

Volcanologists have demonstrated that carbon dioxide (CO2) fluxes are precursors of volcanic eruptions. Controlling volcanic gases and, in particular, the CO2 flux, is technically challenging, but we can retrieve useful information from magmatic/geological process studies for the mitigation of volcanic hazards including air traffic security. Existing techniques used to probe volcanic gas fluxes have severe limitations such as the requirement of near-vent in situ measurements, which is unsafe for operators and deleterious for equipment. In order to overcome these limitations, a novel range-resolved DIAL-Lidar (Differential Absorption Light Detection and Ranging) has been developed as part of the ERC (European Research Council) Project “BRIDGE”, for sensitive, remote, and safe real-time CO2 observations. Here, we report on data collection, processing techniques, and the most significant findings of the experimental campaigns carried out at the most hazardous volcanic areas in Italy: Pozzuoli Solfatara (Phlegraen Fields), Stromboli, and Mt. Etna. The BrIdge voLcanic LIdar—BILLI has successfully obtained accurate measurements of in-plume CO2 concentration and flux. In addition, wind velocity has also been retrieved. It has been shown that the measurements of CO2 concentration performed by BILLI are comparable to those carried out by volcanologists with other standard techniques, heralding a new era in the observation of long-term volcanic gases.

scholarly journals Application of Liquid Hydrogen Carriers in Hydrogen Steelmaking

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1392
Author(s):  
Joakim Andersson
Keyword(s):  
Process Integration ◽  
Direct Reduction ◽  
The Other ◽  
Liquid Form ◽  
Industrial Carbon ◽  
Capital Costs ◽  
Attractive Option ◽  
Thermochemical Processes ◽  
Carbon Dioxide Co2 ◽  
Capacity Cost

Steelmaking is responsible for approximately one third of total industrial carbon dioxide (CO2) emissions. Hydrogen (H2) direct reduction (H-DR) may be a feasible route towards the decarbonization of primary steelmaking if H2 is produced via electrolysis using fossil-free electricity. However, electrolysis is an electricity-intensive process. Therefore, it is preferable that H2 is predominantly produced during times of low electricity prices, which is enabled by storage of H2. This work compares the integration of H2 storage in four liquid carriers, methanol (MeOH), formic acid (FA), ammonia (NH3) and perhydro-dibenzyltoluene (H18-DBT), in H-DR processes. In contrast to conventional H2 storage methods, these carriers allow for H2 storage in liquid form at ambient moderate overpressures, reducing the storage capacity cost. The main downside to liquid H2 carriers is that thermochemical processes are necessary for both the storage and release processes, often with significant investment and operational costs. The carriers are compared using thermodynamic and economic data to estimate operational and capital costs in the H-DR context considering process integration options. It is concluded that the use of MeOH is promising compared to both the other considered carriers. For large storage volumes, MeOH-based H2 storage may also be an attractive option for the underground storage of compressed H2. The other considered liquid H2 carriers suffer from large thermodynamic barriers for hydrogenation (FA) or dehydrogenation (NH3, H18-DBT) and higher investment costs. However, for the use of MeOH in an H-DR process to be practically feasible, questions regarding process flexibility and the optimal sourcing of CO2 and heat must be answered.

The infrared spectrum of CS

1984 ◽  
Vol 62 (12) ◽  
pp. 1414-1419 ◽  
Author(s):  
R. J. Winkel Jr. ◽  
Sumner P. Davis ◽  
Rubén Pecyner ◽  
James W. Brault
Keyword(s):  
Fourier Transform ◽  
Infrared Emission ◽  
Solar Observatory ◽  
Band Head ◽  
The Other ◽  
Fourier Transform Spectrometer ◽  
National Solar Observatory ◽  
Carbon Monosulfide ◽  
Vibration Rotation ◽  
The Fourier Transform

The infrared emission spectrum of carbon monosulfide was observed as a sequence of vibration–rotation bands in the X1Σ+ state, with strong heads of the Δν = 2 sequence degraded to the red. Eight bands of 12C32S were identified, and bands corresponding to the isotope 12C34S were also observed. The most prominent band head, that of the (2–0) band, is at 2585 cm−1, with the other heads spaced approximately 26 cm−1 to smaller wavenumbers. Our data, taken with the Fourier transform spectrometer at the National Solar Observatory (Kitt Peak) include the first reported laboratory observations of the band heads and as many as 200 lines in each band. These observations allowed the calculation of vibrational and rotational constants to higher order than previously reported.

scholarly journals Algorithm theoretical baseline for formaldehyde retrievals from S5P TROPOMI and from the QA4ECV project

2018 ◽  
Vol 11 (4) ◽  
pp. 2395-2426 ◽  
Author(s):  
Isabelle De Smedt ◽  
Nicolas Theys ◽  
Huan Yu ◽  
Thomas Danckaert ◽  
Christophe Lerot ◽  
...  
Keyword(s):  
Near Infrared ◽  
Horizontal Resolution ◽  
Retrieval Algorithm ◽  
User Requirements ◽  
Vertical Column ◽  
Ultraviolet Range ◽  
Order Of Magnitude ◽  
Shortwave Infrared ◽  
Double Channel ◽  
The Eu

Abstract. On board the Copernicus Sentinel-5 Precursor (S5P) platform, the TROPOspheric Monitoring Instrument (TROPOMI) is a double-channel, nadir-viewing grating spectrometer measuring solar back-scattered earthshine radiances in the ultraviolet, visible, near-infrared, and shortwave infrared with global daily coverage. In the ultraviolet range, its spectral resolution and radiometric performance are equivalent to those of its predecessor OMI, but its horizontal resolution at true nadir is improved by an order of magnitude. This paper introduces the formaldehyde (HCHO) tropospheric vertical column retrieval algorithm implemented in the S5P operational processor and comprehensively describes its various retrieval steps. Furthermore, algorithmic improvements developed in the framework of the EU FP7-project QA4ECV are described for future updates of the processor. Detailed error estimates are discussed in the light of Copernicus user requirements and needs for validation are highlighted. Finally, verification results based on the application of the algorithm to OMI measurements are presented, demonstrating the performances expected for TROPOMI.

scholarly journals EXTRACTING BUILT-UP FEATURES IN COMPLEX BIOPHYSICAL ENVIRONMENTS BY USING A LANDSAT BANDS RATIO

2020 ◽  
Vol XLIV-M-2-2020 ◽  
pp. 79-85
Author(s):  
A. H. Ngandam Mfondoum ◽  
P. G. Gbetkom ◽  
R. Cooper ◽  
S. Hakdaoui ◽  
M. B. Mansour Badamassi
Keyword(s):  
Remote Sensing ◽  
Spatial Resolution ◽  
Satellite Data ◽  
Kappa Coefficient ◽  
Landsat 8 ◽  
Experimental Site ◽  
Soil Features ◽  
Mixed Pixels ◽  
Shortwave Infrared ◽  
Normalization Process

Abstract. This paper addresses the remote sensing challenging field of urban mixed pixels on a medium spatial resolution satellite data. The tentatively named Normalized Difference Built-up and Surroundings Unmixing Index (NDBSUI) is proposed by using Landsat-8 Operational Land Imager (OLI) bands. It uses the Shortwave Infrared 2 (SWIR2) as the main wavelength, the SWIR1 with the red wavelengths, for the built-up extraction. A ratio is computed based on the normalization process and the application is made on six cities with different urban and environmental characteristics. The built-up of the experimental site of Yaoundé is extracted with an overall accuracy of 95.51% and a kappa coefficient of 0.90. The NDBSUI is validated over five other sites, chosen according to Cameroon’s bioclimatic zoning. The results are satisfactory for the cities of Yokadouma and Kumba in the bimodal and monomodal rainfall zones, where overall accuracies are up to 98.9% and 97.5%, with kappa coefficients of 0.88 and 0.94 respectively, although these values are close to those of three other indices. However, in the cities of Foumban, Ngaoundéré and Garoua, representing the western highlands, the high Guinea savannah and the Sudano-sahelian zones where built-up is more confused with soil features, overall accuracies of 97.06%, 95.29% and 74.86%, corresponding to 0.918, 0.89 and 0.42 kappa coefficients were recorded. Difference of accuracy with EBBI, NDBI and UI are up to 31.66%, confirming the NDBSUI efficiency to automate built-up extraction and unmixing from surrounding noises with less biases.

scholarly journals Mapping the Unseen: Exploiting Super-Resolution for Semantic Segmentation in Low-Resolution Images

2020 ◽  
Author(s):  
Matheus B. Pereira ◽  
Jefersson Alex Dos Santos
Keyword(s):  
Remote Sensing ◽  
Pattern Recognition ◽  
Super Resolution ◽  
Remote Sensing Data ◽  
Semantic Segmentation ◽  
The Other ◽  
Aerial Imagery ◽  
Aerial Images ◽  
Remote Sensing Images ◽  
Low Resolution

High-resolution aerial images are usually not accessible or affordable. On the other hand, low-resolution remote sensing data is easily found in public open repositories. The problem is that the low-resolution representation can compromise pattern recognition algorithms, especially semantic segmentation. In this M.Sc. dissertation1 , we design two frameworks in order to evaluate the effectiveness of super-resolution in the semantic segmentation of low-resolution remote sensing images. We carried out an extensive set of experiments on different remote sensing datasets. The results show that super-resolution is effective to improve semantic segmentation performance on low-resolution aerial imagery, outperforming unsupervised interpolation and achieving semantic segmentation results comparable to highresolution data.

scholarly journals Detection of Volcanic Plumes by GPS: the 23 November 2013 Episode on Mt. Etna

2015 ◽  
Vol 57 ◽  
Author(s):  
Massimo Aranzulla ◽  
Flavio Cannavò ◽  
Simona Scollo
Keyword(s):  
Signal To Noise Ratio ◽  
Explosive Eruptions ◽  
Volcanic Plume ◽  
Test Case ◽  
Signal To Noise ◽  
Volcanic Plumes ◽  
Gps Network ◽  
Mt Etna ◽  
New Challenges ◽  
Aviation Operations

<p>The detection of volcanic plumes produced during explosive eruptions is important to improve our understanding on dispersal processes and reduce risks to aviation operations. The ability of Global Position-ing System (GPS) to retrieve volcanic plumes is one of the new challenges of the last years in volcanic plume detection. In this work, we analyze the Signal to Noise Ratio (SNR) data from 21 permanent stations of the GPS network of the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, that are located on the Mt. Etna (Italy) flanks. Being one of the most explosive events since 2011, the eruption of November 23, 2013 was chosen as a test-case. Results show some variations in the SNR data that can be correlated with the presence of an ash-laden plume in the atmosphere. Benefits and limitations of the method are highlighted.</p>

scholarly journals IMPACT EVALUATION OF CARBON DIOXIDE (CO2) IN BHOPAL DUE TO INCREASE IN NUMBER OF PASSENGER CARS

2019 ◽  
Vol 7 (7) ◽  
pp. 422-431
Author(s):  
Niranjan Mudliar ◽  
Paramjeet Singh
Keyword(s):  
Carbon Dioxide ◽  
Public Transport ◽  
Income Group ◽  
The Other ◽  
State Governments ◽  
Passenger Cars ◽  
Lower Income Group ◽  
The Government ◽  
Carbon Dioxide Co2 ◽  
The City

India has been progressing steadily since last two decades in terms of affordability of commodity and purchasing power of the common man. This has given rise to demand which leads to the continuous economic growth. Of course, support from the Government of India as well as various state Governments has come in the form of reforms and infrastructure funding. However this growth has also seen the disadvantage of erratic consumption by wealthy persons as compared to the economically weaker sections, for example on one side there is heavy demand of passenger cars by the higher income group who uses it sparingly but on the other side people of the lower income group who are more in numbers have to rely on public transport. This imbalance creates a wider gap between public affordability to consume a particular commodity like passenger cars. On one side there are persons who buy the latest model introduced by the manufacturer in spite of having sufficient numbers at their disposal and on the other side basic lowest level model are out of reach of some persons in the society, who rely on two-wheeler or public transport which is not reliable. This has not only created a huge gap in public expenditure but has also impact the environment. With year on year increase in number of vehicles in tier 2 cities like Bhopal, there is tremendous influence on the carbon dioxide (CO2) in and around the city. Past decade saw increase in maximum temperatures during summer rise by 3 – 4 degrees above normal in Bhopal and there is clear effect on the monsoon pattern too which has become inconsistent with rains reaching 120 mm in three days. Earlier this quantity was spread over a month. The last major season of winter is seen getting reduced to two months only from the earlier four, again with temperatures dropping suddenly below normal etc. This effect must be the result of increasing number of passenger vehicles in the city apart from other factors which also need detailed study for their influence.

scholarly journals An Intercomparison of Ground-Based Solar FTIR Measurements of Atmospheric Gases at Eureka, Canada

2008 ◽  
Vol 25 (11) ◽  
pp. 2028-2036 ◽  
Author(s):  
C. Paton-Walsh ◽  
R. L. Mittermeier ◽  
W. Bell ◽  
H. Fast ◽  
N. B. Jones ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Atmospheric Composition ◽  
The Sun ◽  
Composition Change ◽  
Atmospheric Gases ◽  
Vertical Column ◽  
Error Bars ◽  
Carbon Dioxide Co2 ◽  
Level Of Agreement

Abstract The authors report the results of an intercomparison of vertical column amounts of hydrogen chloride (HCl), hydrogen fluoride (HF), nitrous oxide (N2O), nitric acid (HNO3), methane (CH4), ozone (O3), carbon dioxide (CO2), and nitrogen (N2) derived from the spectra recorded by two ground-based Fourier transform infrared (FTIR) spectrometers operated side-by-side using the sun as a source. The procedure used to record spectra and derive vertical column amounts follows the format of previous instrument intercomparisons organized by the Network for the Detection of Atmospheric Composition Change (NDACC), formerly known as the Network for Detection of Stratospheric Change (NDSC). For most gases the differences were typically around 3%, and in about half of the results the error bars given by the standard deviation of the measurements from each instrument did not overlap. The worst level of agreement was for HF where differences of over 5% were typical. The level of agreement achieved during this intercomparison is a little worse than that achieved in previous intercomparisons between ground-based FTIR spectrometers.

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