317 results on '"Broquet, Grégoire"'
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2. Evaluation of light atmospheric plume inversion methods using synthetic XCO[formula omitted] satellite images to compute Paris CO[formula omitted] emissions
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Danjou, Alexandre, Broquet, Grégoire, Lian, Jinghui, Bréon, François-Marie, and Lauvaux, Thomas
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- 2024
- Full Text
- View/download PDF
3. Satellite-based estimates of decline and rebound in China's CO$_2$ emissions during COVID-19 pandemic
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Zheng, Bo, Geng, Guannan, Ciais, Philippe, Davis, Steven J., Martin, Randall V., Meng, Jun, Wu, Nana, Chevallier, Frederic, Broquet, Gregoire, Boersma, Folkert, van der A, Ronald, Lin, Jintai, Guan, Dabo, Lei, Yu, He, Kebin, and Zhang, Qiang
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Physics - Atmospheric and Oceanic Physics ,Physics - Physics and Society - Abstract
Changes in CO$_2$ emissions during the COVID-19 pandemic have been estimated from indicators on activities like transportation and electricity generation. Here, we instead use satellite observations together with bottom-up information to track the daily dynamics of CO$_2$ emissions during the pandemic. Unlike activity data, our observation-based analysis can be independently evaluated and can provide more detailed insights into spatially-explicit changes. Specifically, we use TROPOMI observations of NO$_2$ to deduce ten-day moving averages of NO$_x$ and CO$_2$ emissions over China, differentiating emissions by sector and province. Between January and April 2020, China's CO$_2$ emissions fell by 11.5% compared to the same period in 2019, but emissions have since rebounded to pre-pandemic levels owing to the fast economic recovery in provinces where industrial activity is concentrated.
- Published
- 2020
4. Local Anomalies in the Column‐Averaged Dry Air Mole Fractions of Carbon Dioxide Across the Globe During the First Months of the Coronavirus Recession
- Author
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Chevallier, Frédéric, Zheng, Bo, Broquet, Grégoire, Ciais, Philippe, Liu, Zhu, Davis, Steven J, Deng, Zhu, Wang, Yilong, Bréon, François‐Marie, and O'Dell, Christopher W
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Climate Action ,carbon dioxide ,emissions ,OCO‐ ,2 ,Paris Agreement ,plume ,satellite ,OCO‐2 ,Meteorology & Atmospheric Sciences - Abstract
We use a global transport model and satellite retrievals of the carbon dioxide (CO2) column average to explore the impact of CO2 emissions reductions that occurred during the economic downturn at the start of the Covid-19 pandemic. The changes in the column averages are substantial in a few places of the model global grid, but the induced gradients are most often less than the random errors of the retrievals. The current necessity to restrict the quality-assured column retrievals to almost cloud-free areas appears to be a major obstacle in identifying changes in CO2 emissions. Indeed, large changes have occurred in the presence of clouds, and in places that were cloud free in 2020, the comparison with previous years is hampered by different cloud conditions during these years. We therefore recommend to favor all-weather CO2 monitoring systems, at least in situ, to support international efforts to reduce emissions.
- Published
- 2020
5. Evaluation of light atmospheric plume inversion methods using synthetic XCO2 satellite images to compute Paris CO2 emissions
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Danjou, Alexandre, primary, Broquet, Grégoire, additional, Lian, Jinghui, additional, Bréon, François-Marie, additional, and Lauvaux, Thomas, additional
- Published
- 2024
- Full Text
- View/download PDF
6. Carbon and greenhouse gas budgets of Europe: trends, interannual and spatial variability, and their drivers
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Lauerwald, Ronny, primary, Bastos, Ana, additional, McGrath, Matthew J, additional, Petrescu, Ana-Maria-Roxana, additional, Ritter, François, additional, Andrew, Robbie M, additional, Berchet, Antoine, additional, Broquet, Grégoire, additional, Brunner, Dominik, additional, Chevallier, Frederic, additional, Cescatti, Alessandro, additional, Filipek, Sara, additional, Fortems-Cheiney, Audrey, additional, Forzieri, Giovanni, additional, Friedlingstein, Pierre, additional, Fuchs, Richard, additional, Gerbig, Christoph, additional, Houweling, Sander, additional, Ke, Piyu, additional, Lerink, Bas J.W., additional, Li, Wei, additional, Li, Xiaojun, additional, Luijkx, Ingrid Theodora, additional, Monteil, Guillaume, additional, Munassar, Saqr, additional, Nabuurs, Gert-Jan, additional, Patra, Prabir K., additional, Peylin, Philippe, additional, Pongratz, Julia, additional, Regnier, Pierre, additional, SAUNOIS, Marielle, additional, Schelhaas, Mart-Jan, additional, Scholze, Marko, additional, Sitch, Stephen, additional, Thompson, Rona L., additional, Tian, Hanqin, additional, Tsuruta, Aki, additional, Wilson, Chris, additional, Wigneron, Jean-Pierre, additional, YAO, YITONG, additional, Zaehle, Sönke, additional, Ciais, Philippe, additional, and Li, Wanjing, additional
- Published
- 2024
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7. NOx emissions in France in 2019–2021 as estimated by the high-spatial-resolution assimilation of TROPOMI NO2 observations.
- Author
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Plauchu, Robin, Fortems-Cheiney, Audrey, Broquet, Grégoire, Pison, Isabelle, Berchet, Antoine, Potier, Elise, Dufour, Gaëlle, Coman, Adriana, Savas, Dilek, Siour, Guillaume, and Eskes, Henk
- Abstract
Since 2018, the TROPOspheric Monitoring Instrument (TROPOMI) on board the Sentinel-5 Precursor (S5P) has provided unprecedented images of nitrogen dioxide (NO2) tropospheric columns at a relatively high spatial resolution with a daily revisit. This study aims at assessing the potential of TROPOMI–PAL data to estimate the national to urban NOx emissions in France from 2019 to 2021, using the variational mode of the recent Community Inversion Framework (CIF) coupled to the CHIMERE regional transport model at a spatial resolution of 10 km × 10 km. The seasonal to inter-annual variations in the French NOx emissions are analyzed. Special attention is paid to the current capability to quantify strong anomalies in the NOx emissions at intra-annual scales, such as the ones due to the COVID-19 pandemic, by using TROPOMI NO2 observations. At the annual scale, the inversions suggest a decrease in the average emissions over 2019–2021 of - 3 % compared to the national budget from the Copernicus Atmosphere Monitoring Service regional inventory (CAMS-REG) for the year 2016, which is used as a prior estimate of the national-scale emissions for each year by the Bayesian inversion framework. This is lower than the decrease of - 14 % from 2016 to the average over 2019–2021 in the estimates of the French Technical Reference Center for Air Pollution and Climate Change (CITEPA). The lower decrease in the inversion results may be linked in large part to the limited level of constraint brought by the TROPOMI data, due to the observation coverage and the ratio between the current level of errors in the observation and the chemistry-transport model, and to the NO2 signal from the French anthropogenic sources. Focusing on local analysis and selecting the days during which the TROPOMI coverage is good over a specific local source, we compute the reductions in the anthropogenic NOx emission estimates by the inversions from spring 2019 to spring 2020. These reductions are particularly pronounced for the largest French urban areas with high emission levels (e.g., - 26 % from April 2019 to April 2020 in the Paris urban area), reflecting reductions in the intensity of vehicle traffic reported during the lockdown period. However, the system does not show large emission decreases for some of the largest cities in France (such as Bordeaux, Nice and Toulouse), even though they were also impacted by the lockdown measures. Despite the current limitations for the monitoring of emissions at the national scale, or for some of the largest cities in France, these results open positive perspectives regarding the ability to support the validation or improvement of inventories with satellite observations, at least at the local level. This leads to discussions on the need for a stepwise improvement of the inversion configuration for a better extraction and extrapolation in space and time of the information from the satellite observations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
8. The ddeq Python library for point source quantification from remote sensing images (version 1.0).
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Kuhlmann, Gerrit, Koene, Erik, Meier, Sandro, Santaren, Diego, Broquet, Grégoire, Chevallier, Frédéric, Hakkarainen, Janne, Nurmela, Janne, Amorós, Laia, Tamminen, Johanna, and Brunner, Dominik
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GAUSSIAN beams ,FACTORIES ,CARBON dioxide ,CITIES & towns ,POWER plants ,AIRBORNE-based remote sensing - Abstract
Atmospheric emissions from anthropogenic hotspots, i.e., cities, power plants and industrial facilities, can be determined from remote sensing images obtained from airborne and space-based imaging spectrometers. In this paper, we present a Python library for data-driven emission quantification (ddeq) that implements various computationally light methods such as the Gaussian plume inversion, cross-sectional flux method, integrated mass enhancement method and divergence method. The library provides a shared interface for data input and output and tools for pre- and post-processing of data. The shared interface makes it possible to easily compare and benchmark the different methods. The paper describes the theoretical basis of the different emission quantification methods and their implementation in the ddeq library. The application of the methods is demonstrated using Jupyter notebooks included in the library, for example, for NO 2 images from the Sentinel-5P/TROPOMI satellite and for synthetic CO 2 and NO 2 images from the Copernicus CO 2 Monitoring (CO2M) satellite constellation. The library can be easily extended for new datasets and methods, providing a powerful community tool for users and developers interested in emission monitoring using remote sensing images. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
9. Recent Changes in Global Photosynthesis and Terrestrial Ecosystem Respiration Constrained From Multiple Observations
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Li, Wei, Ciais, Philippe, Wang, Yilong, Yin, Yi, Peng, Shushi, Zhu, Zaichun, Bastos, Ana, Yue, Chao, Ballantyne, Ashley P, Broquet, Grégoire, Canadell, Josep G, Cescatti, Alessandro, Chen, Chi, Cooper, Leila, Friedlingstein, Pierre, Le Quéré, Corinne, Myneni, Ranga B, and Piao, Shilong
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Life on Land ,GPP trend ,Bayesian constraint ,terrestrial ecosystem respiration ,Meteorology & Atmospheric Sciences - Abstract
To assess global carbon cycle variability, we decompose the net land carbon sink into the sum of gross primary productivity (GPP), terrestrial ecosystem respiration (TER), and fire emissions and apply a Bayesian framework to constrain these fluxes between 1980 and 2014. The constrained GPP and TER fluxes show an increasing trend of only half of the prior trend simulated by models. From the optimization, we infer that TER increased in parallel with GPP from 1980 to 1990, but then stalled during the cooler periods, in 1990–1994 coincident with the Pinatubo eruption, and during the recent warming hiatus period. After each of these TER stalling periods, TER is found to increase faster than GPP, explaining a relative reduction of the net land sink. These results shed light on decadal variations of GPP and TER and suggest that they exhibit different responses to temperature anomalies over the last 35 years.
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- 2018
10. NOx emissions in France in 2019–2021 as estimated by the high spatial resolution assimilation of TROPOMI NO2 observations
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Plauchu, Robin, primary, Fortems-Cheiney, Audrey, additional, Broquet, Grégoire, additional, Pison, Isabelle, additional, Berchet, Antoine, additional, Potier, Elise, additional, Dufour, Gaëlle, additional, Coman, Adriana, additional, Savas, Dilek, additional, Siour, Guillaume, additional, and Eskes, Henk, additional
- Published
- 2024
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11. Supplementary material to "The ddeq Python library for point source quantification from remote sensing images (Version 1.0)"
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Kuhlmann, Gerrit, primary, Koene, Erik F. M., additional, Meier, Sandro, additional, Santaren, Diego, additional, Broquet, Grégoire, additional, Chevallier, Frédéric, additional, Hakkarainen, Janne, additional, Nurmela, Janne, additional, Amorós, Laia, additional, Tamminen, Johanna, additional, and Brunner, Dominik, additional
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- 2024
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12. The ddeq Python library for point source quantification from remote sensing images (Version 1.0)
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Kuhlmann, Gerrit, primary, Koene, Erik F. M., additional, Meier, Sandro, additional, Santaren, Diego, additional, Broquet, Grégoire, additional, Chevallier, Frédéric, additional, Hakkarainen, Janne, additional, Nurmela, Janne, additional, Amorós, Laia, additional, Tamminen, Johanna, additional, and Brunner, Dominik, additional
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- 2024
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13. Supplementary material to "Reconciliation of observation- and inventory- based methane emissions for eight large global emitters"
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Petrescu, Ana Maria Roxana, primary, Peters, Glen P., additional, Engelen, Richard, additional, Houweling, Sander, additional, Brunner, Dominik, additional, Tsuruta, Aki, additional, Matthews, Bradley, additional, Patra, Prabir K., additional, Belikov, Dmitry, additional, Thompson, Rona L., additional, Höglund-Isaksson, Lena, additional, Zhang, Wenxin, additional, Segers, Arjo J., additional, Etiope, Giuseppe, additional, Ciotoli, Giancarlo, additional, Peylin, Philippe, additional, Chevallier, Frédéric, additional, Aalto, Tuula, additional, Andrew, Robbie M., additional, Bastviken, David, additional, Berchet, Antoine, additional, Broquet, Grégoire, additional, Conchedda, Giulia, additional, Gütschow, Johannes, additional, Haussaire, Jean-Matthieu, additional, Lauerwald, Ronny, additional, Markkanen, Tiina, additional, van Peet, Jacob C. A., additional, Pison, Isabelle, additional, Regnier, Pierre, additional, Solum, Espen, additional, Scholze, Marko, additional, Tenkanen, Maria, additional, Tubiello, Francesco N., additional, van der Werf, Guido R., additional, and Worden, John R., additional
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- 2024
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14. Benchmarking data-driven inversion methods for the estimation of local CO2 emissions from XCO2 and NO2 satellite images
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Santaren, Diego, primary, Hakkarainen, Janne, additional, Kuhlmann, Gerrit, additional, Koene, Erik, additional, Chevallier, Frédéric, additional, Ialongo, Iolanda, additional, Lindqvist, Hannakaisa, additional, Nurmela, Janne, additional, Tamminen, Johanna, additional, Amoros, Laia, additional, Brunner, Dominik, additional, and Broquet, Grégoire, additional
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- 2024
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15. Reconciliation of observation- and inventory- based methane emissions for eight large global emitters
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Petrescu, Ana Maria Roxana, primary, Peters, Glen P., additional, Engelen, Richard, additional, Houweling, Sander, additional, Brunner, Dominik, additional, Tsuruta, Aki, additional, Matthews, Bradley, additional, Patra, Prabir K., additional, Belikov, Dmitry, additional, Thompson, Rona L., additional, Höglund-Isaksson, Lena, additional, Zhang, Wenxin, additional, Segers, Arjo J., additional, Etiope, Giuseppe, additional, Ciotoli, Giancarlo, additional, Peylin, Philippe, additional, Chevallier, Frédéric, additional, Aalto, Tuula, additional, Andrew, Robbie M., additional, Bastviken, David, additional, Berchet, Antoine, additional, Broquet, Grégoire, additional, Conchedda, Giulia, additional, Gütschow, Johannes, additional, Haussaire, Jean-Matthieu, additional, Lauerwald, Ronny, additional, Markkanen, Tiina, additional, van Peet, Jacob C. A., additional, Pison, Isabelle, additional, Regnier, Pierre, additional, Solum, Espen, additional, Scholze, Marko, additional, Tenkanen, Maria, additional, Tubiello, Francesco N., additional, van der Werf, Guido R., additional, and Worden, John R., additional
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- 2024
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16. Fossil fuel CO2 emissions over metropolitan areas from space: A multi-model analysis of OCO-2 data over Lahore, Pakistan
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Lei, Ruixue, Feng, Sha, Danjou, Alexandre, Broquet, Grégoire, Wu, Dien, Lin, John C., O'Dell, Christopher W., and Lauvaux, Thomas
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- 2021
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17. Deep learning applied to CO2 power plant emissions quantification using simulated satellite images.
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Dumont Le Brazidec, Joffrey, Vanderbecken, Pierre, Farchi, Alban, Broquet, Grégoire, Kuhlmann, Gerrit, and Bocquet, Marc
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DEEP learning ,REMOTE-sensing images ,POWER plants ,CARBON dioxide ,CONVOLUTIONAL neural networks ,GREENHOUSE gases ,AIR pollutants - Abstract
The quantification of emissions of greenhouse gases and air pollutants through the inversion of plumes in satellite images remains a complex problem that current methods can only assess with significant uncertainties. The anticipated launch of the CO2M (Copernicus Anthropogenic Carbon Dioxide Monitoring) satellite constellation in 2026 is expected to provide high-resolution images of CO2 (carbon dioxide) column-averaged mole fractions (XCO2), opening up new possibilities. However, the inversion of future CO2 plumes from CO2M will encounter various obstacles. A challenge is the low CO2 plume signal-to-noise ratio due to the variability in the background and instrumental errors in satellite measurements. Moreover, uncertainties in the transport and dispersion processes further complicate the inversion task. To address these challenges, deep learning techniques, such as neural networks, offer promising solutions for retrieving emissions from plumes in XCO2 images. Deep learning models can be trained to identify emissions from plume dynamics simulated using a transport model. It then becomes possible to extract relevant information from new plumes and predict their emissions. In this paper, we develop a strategy employing convolutional neural networks (CNNs) to estimate the emission fluxes from a plume in a pseudo- XCO2 image. Our dataset used to train and test such methods includes pseudo-images based on simulations of hourly XCO2 , NO2 (nitrogen dioxide), and wind fields near various power plants in eastern Germany, tracing plumes from anthropogenic and biogenic sources. CNN models are trained to predict emissions from three power plants that exhibit diverse characteristics. The power plants used to assess the deep learning model's performance are not used to train the model. We find that the CNN model outperforms state-of-the-art plume inversion approaches, achieving highly accurate results with an absolute error about half of that of the cross-sectional flux method and an absolute relative error of ∼ 20 % when only the XCO2 and wind fields are used as inputs. Furthermore, we show that our estimations are only slightly affected by the absence of NO2 fields or a detection mechanism as additional information. Finally, interpretability techniques applied to our models confirm that the CNN automatically learns to identify the XCO2 plume and to assess emissions from the plume concentrations. These promising results suggest a high potential of CNNs in estimating local CO2 emissions from satellite images. [ABSTRACT FROM AUTHOR]
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- 2024
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18. Using metal oxide gas sensors for the estimate of methane controlled releases: reconstruction of the methane mole fraction time-series and quantification of the release rates and locations
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Rivera Martinez, Rodrigo Andres, primary, Kumar, Pramod, additional, Laurent, Olivier, additional, Broquet, Grégoire, additional, Caldow, Christopher, additional, Cropley, Ford, additional, Santaren, Diego, additional, Shah, Adil, additional, Mallet, Cécile, additional, Ramonet, Michel, additional, Rivier, Leonard, additional, Juery, Catherine, additional, Duclaux, Olivier, additional, Bouchet, Caroline, additional, Allegrini, Elisa, additional, Utard, Hervé, additional, and Ciais, Philippe, additional
- Published
- 2023
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19. Optimal selection of satellite XCO2 images over cities for urban CO2 emission monitoring using a global adaptive-mesh model
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Danjou, Alexandre, primary, Broquet, Grégoire, additional, Schuh, Andrew, additional, Bréon, François-Marie, additional, and Lauvaux, Thomas, additional
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- 2023
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20. Towards understanding the variability in source contribution of CO2 using high-resolution simulations of atmospheric δ13CO2 signatures in the Greater Toronto Area, Canada
- Author
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Domenikos, Stephanie Pugliese, Vogel, Felix R., Murphy, Jennifer G., Moran, Michael D., Stroud, Craig A., Ren, Shuzhan, Zhang, Junhua, Zheng, Qiong, Worthy, Douglas, Huang, Lin, and Broquet, Gregoire
- Published
- 2019
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21. NOx emissions in France in 2019–2021 as estimated by the high spatial resolution assimilation of TROPOMI NO2 observations.
- Author
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Plauchu, Robin, Fortems-Cheiney, Audrey, Broquet, Grégoire, Pison, Isabelle, Berchet, Antoine, Potier, Elise, Dufour, Gaëlle, Coman, Adriana, Savas, Dilek, Siour, Guillaume, and Eskes, Henk
- Subjects
SPATIAL resolution ,CITIES & towns ,KALMAN filtering ,AIR pollution ,COVID-19 pandemic ,CLIMATE change - Abstract
Since 2018, TROPOMI on-board Sentinel-5P provides unprecedented images of NO
2 tropospheric columns at a relatively high spatial resolution with a daily revisit. This study aims at assessing the potential of the TROPOMI-PAL data to estimate the national to urban NOx emissions in France from 2019 to 2021, using the variational mode of the recent Community Inversion Framework coupled to the CHIMERE regional transport model at a spatial resolution of 10×10 km2 . The seasonal to inter-annual variations of the NOx French emissions are analyzed. A specific attention is paid to the current capability to quantify strong anomalies in the NOx emissions at intra-annual scales such as the ones due to the COVID-19 pandemic, by using TROPOMI NO2 observations. The inversions lead to a decrease of the average emissions over 2019–2021 compared to 2016 of -3 % at national scale, which is lower than the decrease of -14 % between these years in the estimates of the French Technical Center for Air Pollution and Climate Change (CITEPA). This may be linked especially to the limited level of constraint brought by the TROPOMI data, due to the observation coverage and the ratio between the current level of errors in the observation and the chemistry-transport model, and the NO2 signal from the French anthropogenic sources. Focusing on local analysis and selecting the days during which the TROPOMI coverage is good over a specific local source, we compute the reductions in the NOx anthropogenic emission estimates by the inversions from spring 2019 to spring 2020. These reductions are particularly pronounced for the largest French urban areas (e.g., -26 % from April 2019 to April 2020 in the Paris urban area) and along major roadways, consistently with the reduction in the intensity of vehicle traffic reported during the lockdown period. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
22. Detection and long-term quantification of methane emissions from an active landfill.
- Author
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Kumar, Pramod, Caldow, Christopher, Broquet, Grégoire, Shah, Adil, Laurent, Olivier, Yver-Kwok, Camille, Ars, Sebastien, Defratyka, Sara, Gichuki, Susan Warao, Lienhardt, Luc, Lozano, Mathis, Paris, Jean-Daniel, Vogel, Felix, Bouchet, Caroline, Allegrini, Elisa, Kelly, Robert, Juery, Catherine, and Ciais, Philippe
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FUGITIVE emissions ,LANDFILL gases ,GREENHOUSE gases ,LANDFILLS ,INFRASTRUCTURE (Economics) ,MOLE fraction ,ATMOSPHERIC pressure - Abstract
Landfills are a significant source of fugitive methane (CH 4) emissions, which should be precisely and regularly monitored to reduce and mitigate net greenhouse gas emissions. In this study, we present long-term, in situ, near-surface, mobile atmospheric CH 4 mole fraction measurements (complemented by meteorological measurements from a fixed station) from 21 campaigns that cover approximately 4 years from September 2016 to December 2020. These campaigns were utilized to regularly quantify the total CH 4 emissions from an active landfill in France. We use a simple atmospheric inversion approach based on a Gaussian plume dispersion model to derive CH 4 emissions. Together with the measurements near the soil surface, mainly dedicated to the identification of sources within the landfill, measurements of CH 4 made on the landfill perimeter (near-field) helped us to identify the main emission areas and to provide some qualitative insights about the rank of their contributions to total emissions from the landfill. The two main area sources correspond, respectively, to a covered waste sector with infrastructure with sporadic leakages (such as wells, tanks, pipes, etc.) and to the last active sector receiving waste during most of the measurement campaigns. However, we hardly managed to extract a signal representative of the overall landfill emissions from the near-field measurements, which limited our ability to derive robust estimates of the emissions when assimilating them in the atmospheric inversions. The analysis shows that the inversions based on the measurements from a remote road further away from the landfill (far-field) yielded reliable estimates of the total emissions but provided less information on the spatial variability of emissions within the landfill. This demonstrates the complementarity between the near- and far-field measurements. According to these inversions, the total CH 4 emissions have a large temporal variability and range from ∼ 0.4 to ∼ 7 t CH 4 d -1 , with an average value of ∼ 2.1 t CH 4 d -1. We find a weak negative correlation between these estimates of the CH 4 emissions and atmospheric pressure for the active landfill. However, this weak emission–pressure relationship is based on a relatively small sample of reliable emission estimates with large sampling gaps. More frequent robust estimations are required to better understand this relationship for an active landfill. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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23. Development and deployment of a mid-cost CO2 sensor monitoring network to support atmospheric inverse modeling for quantifying urban CO2 emissions in Paris.
- Author
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Lian, Jinghui, Laurent, Olivier, Chariot, Mali, Lienhardt, Luc, Ramonet, Michel, Utard, Hervé, Lauvaux, Thomas, Bréon, François-Marie, Broquet, Grégoire, Cucchi, Karina, Millair, Laurent, and Ciais, Philippe
- Subjects
SENSOR networks ,CAVITY-ringdown spectroscopy ,ATMOSPHERIC models ,SOCIAL networks ,INFORMATION storage & retrieval systems ,MULTISCALE modeling ,QUALITY control - Abstract
To effectively monitor the highly heterogeneous urban CO
2 emissions using atmospheric observations, there is a need to deploy cost-effective CO2 sensors at multiple locations within the city with sufficient accuracy to capture the concentration gradients in urban environments. Its measurements could be used as input of an atmospheric inversion system for the quantification of emissions at the sub-city scale or separate specific sectors. Such quantification would offer valuable insights into the efficacy of local initiatives and could also identify unknown emission hotspots that require attention. Here we present the development and evaluation of a mid-cost CO2 instrument designed for continuous monitoring of atmospheric CO2 concentrations with a target accuracy of 1 ppm on hourly mean measurement. We assess the sensor sensitivity in relation to environmental factors such as humidity, pressure, temperature and CO2 signal, which leads to the development of an effective calibration algorithm. Since July 2020, eight mid-cost instruments have been installed within the city of Paris and its vicinity to provide continuous CO2 measurements, complementing the seven high-precision Cavity Ring-Down Spectroscopy (CRDS) stations that have been in operation since 2016. A data processing system, called CO2calqual, has been implemented to automatically handle data quality control, calibration and storage, which enables the management of extensive real-time CO2 measurements from the monitoring network. Colocation assessments with the high-precision instrument show that the accuracies of the eight mid-cost instruments are within the range of 1.0 to 2.4 ppm for hourly afternoon (12–17 UTC) measurements. The long-term stability issues require manual data checks and instrument maintenance. The analyses show that CO2 measurements can provide evidence for underestimations of CO2 emissions in the Paris region and a lack of several emission point sources in the emission inventory. Our study demonstrates promising prospects in integrating mid-cost measurements along with high precision data into the subsequent atmospheric inverse modeling to improve the accuracy of quantifying the fine-scale CO2 emissions in the Paris metropolitan area. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
24. Development and deployment of a mid-cost CO2 sensor monitoring network to support atmospheric inverse modeling for quantifying urban CO2 emissions in Paris.
- Author
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Jinghui Lian, Laurent, Olivier, Chariot, Mali, Lienhardt, Luc, Ramonet, Michel, Utard, Hervé, Lauvaux, Thomas, Bréon, François-Marie, Broquet, Grégoire, Cucchi, Karina, Millair, Laurent, and Ciais, Philippe
- Subjects
SENSOR networks ,CAVITY-ringdown spectroscopy ,ATMOSPHERIC models ,SOCIAL networks ,INFORMATION storage & retrieval systems ,MULTISCALE modeling ,QUALITY control - Abstract
To effectively monitor the highly heterogeneous urban CO
2 emissions using atmospheric observations, there is a need to deploy cost-effective CO2 sensors at multiple locations within the city with sufficient accuracy to capture the concentration gradients in urban environments. Its measurements could be used as input of an atmospheric inversion system for the quantification of emissions at the sub-city scale or separate specific sectors. Such quantification would offer valuable insights into the efficacy of local initiatives and could also identify unknown emission hotspots that require attention. Here we present the development and evaluation of a mid-cost CO2 instrument designed for continuous monitoring of atmospheric CO2 concentrations with a target accuracy of 1 ppm on hourly mean measurement. We assess the sensor sensitivity in relation to environmental factors such as humidity, pressure, temperature and CO2 signal, which leads to the development of an effective calibration algorithm. Since July 2020, eight mid-cost instruments have been installed within the city of Paris and its vicinity to provide continuous CO2 measurements, complementing the seven high-precision Cavity Ring-Down Spectroscopy (CRDS) stations that have been in operation since 2016. A data processing system, called CO2 calqual, has been implemented to automatically handle data quality control, calibration and storage, which enables the management of extensive real-time CO2 measurements from the monitoring network. Colocation assessments with the high-precision instrument show that the accuracies of the eight mid-cost instruments are within the range of 1.0 to 2.4 ppm for hourly afternoon (12–17 UTC) measurements. The long-term stability issues require manual data checks and instrument maintenance. The analyses show that CO2 measurements can provide evidence for underestimations of CO2 emissions in the Paris region and a lack of several emission point sources in the emission inventory. Our study demonstrates promising prospects in integrating mid-cost measurements along with high precision data into the subsequent atmospheric inverse modeling to improve the accuracy of quantifying the fine-scale CO2 emissions in the Paris metropolitan area. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
25. Benchmarking data-driven inversion methods for the estimation of 1 local CO2 emissions from XCO2 and NO2 satellite images.
- Author
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Santaren, Diego, Hakkarainen, Janne, Kuhlmann, Gerrit, Koene, Erik, Chevallier, Frédéric, Ialongo, Iolanda, Lindqvist, Hannakaisa, Nurmela, Janne, Tamminen, Johanna, Amorós, Laia, Brunner, Dominik, and Broquet, Grégoire
- Subjects
REMOTE-sensing images ,LANDSAT satellites ,GEOSTATIONARY satellites ,STANDARD deviations ,CARBON emissions ,ATMOSPHERIC transport ,CLOUDINESS - Abstract
The largest anthropogenic emissions of carbon dioxide (CO
2 ) come from local sources such as cities and power plants. The upcoming Copernicus CO2 Monitoring Mission (CO2M) will provide satellite images of the CO2 and NO2 plumes associated with these sources at a resolution of 2 km x 2 km and with a swath of 250 km. These images could be exploited with atmospheric plume inversion methods to estimate local CO2 emissions at the time of the satellite overpass and the corresponding uncertainties. To support the development of the operational processing of satellite column-average XCO2 and NO2 imagery, this study evaluates "data-driven inversion methods", i.e., computationally light inversion methods that directly process information from satellite images, local winds and meteorological data, without resorting to computationally expensive dynamical atmospheric transport models. We have designed an objective benchmarking exercise to analyse and compare the performance of five different data-driven inversion methods: two implementations with different complexity for the cross-sectional flux approach (CSF and LCSF) and one implementation for the Integrated Mass Enhancement (IME), the Divergence (Div) and the Gaussian Plume model inversion (GP) approaches. This exercise is based on pseudo-data experiments with simulations of synthetic "true" emissions, meteorological and concentration fields, and CO2M observations in a domain of 750 km x 650 km centred on Eastern Germany over 1-year. The performance of the methods is quantified in terms of accuracy in the single-image (from individual images) or annual average (from the full series of images) emission estimates and in terms of number of instant estimates for the city of Berlin and 15 power plants in this domain. Several ensembles of estimations are conducted, using different scenarios for the available synthetic datasets. These ensembles are used to analyse the sensitivity of the performance to the loss of data due to cloud cover, to the uncertainty in the wind or to the added value of simultaneous NO2 images. The GP and the LCSF methods generate the most accurate estimates from individual images with similar Interquartile Ranges (IQR) in the deviations between the emission estimates and the true emissions between ~20 % and ~60 % for all scenarios. When taking the cloud cover into account, these methods produce respectively 274 and 318 instant estimates from the *500 daily images that cover significant portions of the plumes from the sources. Filtering the results based on the associated uncertainty estimates can improve the statistics of the IME and CSF methods, but at the cost of a large decrease in the number of estimates. Due to a reliable estimation of uncertainty and thus a suitable selection of estimates, the CSF method achieves similar if not better statistics of accuracy for instant estimates compared to the GP and LCSF methods after filtering. In general, the performances for retrieving single-image estimates are improved when, in addition to XCO2 data, collocated NO2 data are used to characterise the structure of plumes. With respect to the estimates of annual emissions, the root mean square errors (RMSE) are for the most realistic benchmarking scenario 20 % (GP), 27 % (CSF), 31 % (LCSF), 55 % (IME) and 79 % (Div). This study suggests that the Gaussian plume and/or the cross-sectional approaches are currently the most efficient tools to provide estimates of CO2 emissions from satellite images and their relatively light computational cost will enable analysis of the massive amount of data provided by future missions of satellite XCO2 imagery. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
26. Supplementary material to "Detection and long-term quantification of methane emissions from an active landfill"
- Author
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Kumar, Pramod, primary, Caldow, Christopher, additional, Broquet, Grégoire, additional, Shah, Adil, additional, Laurent, Olivier, additional, Yver-Kwok, Camille, additional, Ars, Sebastien, additional, Defratyka, Sara, additional, Gichuki, Susan, additional, Lienhardt, Luc, additional, Lozano, Mathis, additional, Paris, Jean-Daniel, additional, Vogel, Felix, additional, Bouchet, Caroline, additional, Allegrini, Elisa, additional, Kelly, Robert, additional, Juery, Catherine, additional, and Ciais, Philippe, additional
- Published
- 2023
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27. Detection and long-term quantification of methane emissions from an active landfill
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Kumar, Pramod, primary, Caldow, Christopher, additional, Broquet, Grégoire, additional, Shah, Adil, additional, Laurent, Olivier, additional, Yver-Kwok, Camille, additional, Ars, Sebastien, additional, Defratyka, Sara, additional, Gichuki, Susan, additional, Lienhardt, Luc, additional, Lozano, Mathis, additional, Paris, Jean-Daniel, additional, Vogel, Felix, additional, Bouchet, Caroline, additional, Allegrini, Elisa, additional, Kelly, Robert, additional, Juery, Catherine, additional, and Ciais, Philippe, additional
- Published
- 2023
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- View/download PDF
28. Can we use atmospheric CO2 measurements to verify emission trends reported by cities? Lessons from a 6-year atmospheric inversion over Paris
- Author
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Lian, Jinghui, primary, Lauvaux, Thomas, additional, Utard, Hervé, additional, Bréon, François-Marie, additional, Broquet, Grégoire, additional, Ramonet, Michel, additional, Laurent, Olivier, additional, Albarus, Ivonne, additional, Chariot, Mali, additional, Kotthaus, Simone, additional, Haeffelin, Martial, additional, Sanchez, Olivier, additional, Perrussel, Olivier, additional, Denier van der Gon, Hugo Anne, additional, Dellaert, Stijn Nicolaas Camiel, additional, and Ciais, Philippe, additional
- Published
- 2023
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29. Segmentation of XCO2 images with deep learning: application to synthetic plumes from cities and power plants
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Dumont Le Brazidec, Joffrey, primary, Vanderbecken, Pierre, additional, Farchi, Alban, additional, Bocquet, Marc, additional, Lian, Jinghui, additional, Broquet, Grégoire, additional, Kuhlmann, Gerrit, additional, Danjou, Alexandre, additional, and Lauvaux, Thomas, additional
- Published
- 2023
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30. Segmentation of XCO2 images with deep learning: application to synthetic plumes from cities and power plants
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Dumont Le Brazidec, Joffrey, Vanderbecken, Pierre, Farchi, Alban, Bocquet, Marc, Lian, Jinghui, Broquet, Grégoire, Kuhlmann, Gerrit, Danjou, Alexandre, and Lauvaux, Thomas
- Abstract
Under the Copernicus programme, an operational CO2 Monitoring Verification and Support system (CO2MVS) is being developed and will exploit data from future satellites monitoring the distribution of CO2 within the atmosphere. Methods for estimating CO2 emissions from significant local emitters (hotspots; i.e. cities or power plants) can greatly benefit from the availability of such satellite images that display the atmospheric plumes of CO2. Indeed, local emissions are strongly correlated to the size, shape, and concentration distribution of the corresponding plume, which is a visible consequence of the emission. The estimation of emissions from a given source can therefore directly benefit from the detection of its associated plumes in the satellite image. In this study, we address the problem of plume segmentation (i.e. the problem of finding all pixels in an image that constitute a city or power plant plume). This represents a significant challenge, as the signal from CO2 plumes induced by emissions from cities or power plants is inherently difficult to detect, since it rarely exceeds values of a few parts per million (ppm) and is perturbed by variable regional CO2 background signals and observation errors. To address this key issue, we investigate the potential of deep learning methods and in particular convolutional neural networks to learn to distinguish plume-specific spatial features from background or instrument features. Specifically, a U-Net algorithm, an image-to-image convolutional neural network with a state-of-the-art encoder, is used to transform an XCO2 field into an image representing the positions of the targeted plume. Our models are trained on hourly 1 km simulated XCO2 fields in the regions of Paris, Berlin, and several power plants in Germany. Each field represents the plume of the hotspot, with the background consisting of the signal of anthropogenic and biogenic CO2 surface fluxes near to or far from the targeted source and the simulated satellite observation errors. The performance of the deep learning method is thereafter evaluated and compared with a plume segmentation technique based on thresholding in two contexts, namely (1) where the model is trained and tested on data from the same region and (2) where the model is trained and tested in two different regions. In both contexts, our method outperforms the usual segmentation technique based on thresholding and demonstrates its ability to generalise in various cases, with respect to city plumes, power plant plumes, and areas with multiple plumes. Although less accurate than in the first context, the ability of the algorithm to extrapolate on new geographical data is conclusive, paving the way to a promising universal segmentation model trained on a well-chosen sample of power plants and cities and able to detect the majority of the plumes from all of them. Finally, the highly accurate results for segmentation suggest the significant potential of convolutional neural networks for estimating local emissions from spaceborne imagery.
- Published
- 2023
31. Characterising the methane gas and environmental response of the Figaro Taguchi Gas Sensor (TGS) 2611-E00
- Author
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Shah, Adil, Laurent, Olivier, Lienhardt, Luc, Broquet, Grégoire, Rivera Martinez, Rodrigo, Allegrini, Elisa, Ciais, Philippe, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), ICOS-RAMCES (ICOS-RAMCES), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), and Suez Smart Solutions
- Subjects
[SDU]Sciences of the Universe [physics] - Abstract
In efforts to improve methane source characterisation, networks of cheap high-frequency in situ sensors are required, with parts-per-million-level methane mole fraction ([CH4]) precision. Low-cost semiconductor-based metal oxide sensors, such as the Figaro Taguchi Gas Sensor (TGS) 2611-E00, may satisfy this requirement. The resistance of these sensors decreases in response to the exposure of reducing gases, such as methane. In this study, we set out to characterise the Figaro TGS 2611-E00 in an effort to eventually yield [CH4] when deployed in the field. We found that different gas sources containing the same ambient 2 ppm [CH4] level yielded different resistance responses. For example, synthetically generated air containing 2 ppm [CH4] produced a lower sensor resistance than 2 ppm [CH4] found in natural ambient air due to possible interference from supplementary reducing gas species in ambient air, though the specific cause of this phenomenon is not clear. TGS 2611-E00 carbon monoxide response is small and incapable of causing this effect. For this reason, ambient laboratory air was selected as a testing gas standard to naturally incorporate such background effects into a reference resistance. Figaro TGS 2611-E00 resistance is sensitive to temperature and water vapour mole fraction ([H2O]). Therefore, a reference resistance using this ambient air gas standard was characterised for five sensors (each inside its own field logging enclosure) using a large environmental chamber, where logger enclosure temperature ranged between 8 and 38 ∘C and [H2O] ranged between 0.4 % and 1.9 %. [H2O] dominated resistance variability in the standard gas. A linear [H2O] and temperature model fit was derived, resulting in a root mean squared error (RMSE) between measured and modelled resistance in standard gas of between ±0.4 and ±1.0 kΩ for the five sensors, corresponding to a fractional resistance uncertainty of less than ±3 % at 25 ∘C and 1 % [H2O]. The TGS 2611-E00 loggers were deployed at a landfill site for 242 d before and 96 d after sensor testing. Yet the standard (i.e. ambient air) reference resistance model fit based on temperature and [H2O] could not replicate resistance measurements made in the field, where [CH4] was mostly expected to be close to the ambient background, with minor enhancements. This field disparity may have been due to variability in sensor cooling dynamics, a difference in ambient air composition during environmental chamber testing compared to the field or variability in natural sensor response, either spontaneously or environmentally driven. Despite difficulties in replicating a standard reference resistance in the field, we devised an excellent methane characterisation model up to 1000 ppm [CH4] by using the ratio between measured resistance with [CH4] enhancement and its corresponding reference resistance in standard gas. A bespoke power-type fit between resistance ratio and [CH4] resulted in an RMSE between the modelled and measured resistance ratio of no more than ±1 % Ω Ω−1 for the five sensors. This fit and its corresponding fit parameters were then inverted and the original resistance ratio values were used to derive [CH4], yielding an inverted model [CH4] RMSE of less than ±1 ppm, where [CH4] was limited to 28 ppm. Our methane response model allows other reducing gases to be included if necessary by characterising additional model coefficients. Our model shows that a 1 ppm [CH4] enhancement above the ambient background results in a resistance drop of between 1.4 % and 2.0 % for the five tested sensors. With future improvements in deriving a standard reference resistance, the TGS 2611-E00 offers great potential in measuring [CH4] with parts-per-million-level precision.
- Published
- 2023
32. The potential of a constellation of low earth orbit satellite imagers to monitor worldwide fossil fuel CO2 emissions from large cities and point sources
- Author
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Lespinas, Franck, Wang, Yilong, Broquet, Grégoire, Bréon, François-Marie, Buchwitz, Michael, Reuter, Maximilian, Meijer, Yasjka, Loescher, Armin, Janssens-Maenhout, Greet, Zheng, Bo, and Ciais, Philippe
- Published
- 2020
- Full Text
- View/download PDF
33. Can we use atmospheric CO2 measurements to verify emission trends reported by cities? Lessons from a six-year atmospheric inversion over Paris
- Author
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Lian, Jinghui, primary, Lauvaux, Thomas, additional, Utard, Hervé, additional, Bréon, François-Marie, additional, Broquet, Grégoire, additional, Ramonet, Michel, additional, Laurent, Olivier, additional, Albarus, Ivonne, additional, Chariot, Mali, additional, Kotthaus, Simone, additional, Haeffelin, Martial, additional, Sanchez, Olivier, additional, Perrussel, Olivier, additional, Denier van der Gon, Hugo Anne, additional, Dellaert, Stijn Nicolaas Camiel, additional, and Ciais, Philippe, additional
- Published
- 2023
- Full Text
- View/download PDF
34. Supplementary material to "Can we use atmospheric CO2 measurements to verify emission trends reported by cities? Lessons from a six-year atmospheric inversion over Paris"
- Author
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Lian, Jinghui, primary, Lauvaux, Thomas, additional, Utard, Hervé, additional, Bréon, François-Marie, additional, Broquet, Grégoire, additional, Ramonet, Michel, additional, Laurent, Olivier, additional, Albarus, Ivonne, additional, Chariot, Mali, additional, Kotthaus, Simone, additional, Haeffelin, Martial, additional, Sanchez, Olivier, additional, Perrussel, Olivier, additional, Denier van der Gon, Hugo Anne, additional, Dellaert, Stijn Nicolaas Camiel, additional, and Ciais, Philippe, additional
- Published
- 2023
- Full Text
- View/download PDF
35. Accounting for meteorological biases in simulated plumes using smarter metrics
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Vanderbecken, Pierre J., primary, Dumont Le Brazidec, Joffrey, additional, Farchi, Alban, additional, Bocquet, Marc, additional, Roustan, Yelva, additional, Potier, Élise, additional, and Broquet, Grégoire, additional
- Published
- 2023
- Full Text
- View/download PDF
36. Reducing uncertainties in decadal variability of the global carbon budget with multiple datasets
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Li, Wei, Ciais, Philippe, Wang, Yilong, Peng, Shushi, Broquet, Grégoire, Ballantyne, Ashley P., Canadell, Josep G., Cooper, Leila, Friedlingstein, Pierre, Le Quéré, Corinne, Myneni, Ranga B., Peters, Glen P., Piao, Shilong, and Pongratz, Julia
- Published
- 2016
37. Determining methane mole fraction at a landfill site using the Figaro Taguchi gas sensor 2611-C00 and wind direction measurementsElectronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/d3ea00138e
- Author
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Shah, Adil, Laurent, Olivier, Broquet, Grégoire, Philippon, Carole, Kumar, Pramod, Allegrini, Elisa, and Ciais, Philippe
- Abstract
Top-down (atmospheric measurement-based) methane fluxes from individual emitting facilities are needed to reduce uncertainties in the global methane budget. This typically requires in situmethane mole fraction ([CH4]), traditionally measured using high-precision optical sensors. We show that the semiconductor-based Figaro Taguchi Gas Sensor (TGS) is a cheaper alternative. Two TGS loggers were deployed near a landfill site. Logger-1 uses a pumped cell, containing one TGS 2602, two TGS 2611-C00 and one TGS 2611-E00; laboratory testing showed methane, ethane, carbon monoxide and hydrogen sulphide sensitivity for each TGS. Logger-2 uses an external fan, containing one TGS 2611-C00. The tested TGS 2611-C00 and TGS 2611-E00 units could yield [CH4] during landfill deployment, by first modelling a reference baseline resistance in field conditions, representative of background (reference) [CH4] sampling. Background sampling was identified using wind direction from a designated background segment, which yielded a baseline resistance model as a function of time (incorporating long-term background effects), water mole fraction and temperature. The ratio between measured TGS resistance and modelled baseline resistance was converted into [CH4], using a two-term modified power fit. Logger-1 methane fitting coefficients were derived during laboratory testing, while Logger-2 coefficients used a 1.49% field sampling subset, alongside a high-precision reference (HPR) instrument. Reconstructed minute-averaged Logger-2 [CH4] for TGS 2611-C00 was compared to the HPR up to 31.5 ppm [CH4] (excluding [CH4] fitting data), resulting in a ±0.55 ppm [CH4] root-mean squared error (RMSE), for 295.2 overall sampling days (excluding data gaps). Reconstructed Logger-1 [CH4] RMSE compared to the HPR was ±0.67 ppm and ±0.77 ppm for the two TGS 2611-C00 and ±1.17 ppm for the TGS 2611-E00, up to 29.3 ppm [CH4], for 147.9 overall sampling days. Field TGS 2611-C00 superiority above other Logger-1 sensors is supported by laboratory tests, which showed TGS 2611-C00 to be most methane-sensitive. In summary, we show that the TGS 2611-C00 is an ideal low-cost sensor to measure [CH4] from facility-scale sources, with a field RMSE below ±1 ppm. This work represents the first application of TGS resistance ratios to yield parts-per-million level [CH4] field measurements, using a dynamic baseline resistance model.
- Published
- 2024
- Full Text
- View/download PDF
38. French NOx emissions as estimated from TROPOMI-PAL NO2 observations
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Plauchu, Robin, primary, Fortems-Cheiney, Audrey, additional, Broquet, Grégoire, additional, Pison, Isabelle, additional, Berchet, Antoine, additional, Potier, Elise, additional, Coman, Adriana, additional, Savas, Dilek, additional, and Dufour, Gaëlle, additional
- Published
- 2023
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39. Anthropogenic NOx Emission Estimations over East China for 2015 and 2019 Using OMI Satellite Observations and the New Inverse Modeling System CIF-CHIMERE
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Savas, Dilek, primary, Dufour, Gaëlle, additional, Coman, Adriana, additional, Siour, Guillaume, additional, Fortems-Cheiney, Audrey, additional, Broquet, Grégoire, additional, Pison, Isabelle, additional, Berchet, Antoine, additional, and Bessagnet, Bertrand, additional
- Published
- 2023
- Full Text
- View/download PDF
40. Segmentation of XCO2 images with deep learning: application to synthetic plumes from cities and power plants
- Author
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Dumont Le Brazidec, Joffrey, primary, Vanderbecken, Pierre, additional, Farchi, Alban, additional, Bocquet, Marc, additional, Lian, Jinghui, additional, Broquet, Grégoire, additional, Kuhlmann, Gerrit, additional, Danjou, Alexandre, additional, and Lauvaux, Thomas, additional
- Published
- 2022
- Full Text
- View/download PDF
41. Characterising Methane Gas and Environmental Response of the Figaro Taguchi Gas Sensor (TGS) 2611-E00
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Shah, Adil, primary, Laurent, Olivier, additional, Lienhardt, Luc, additional, Broquet, Grégoire, additional, Rivera Martinez, Rodrigo, additional, Allegrini, Elisa, additional, and Ciais, Philippe, additional
- Published
- 2022
- Full Text
- View/download PDF
42. Impact of assimilating physical oceanographic data on modeled ecosystem dynamics in the California Current System
- Author
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Raghukumar, Kaustubha, Edwards, Christopher A., Goebel, Nicole L., Broquet, Gregoire, Veneziani, Milena, Moore, Andrew M., and Zehr, Jon P.
- Published
- 2015
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43. Detection and long-term quantification of methane emissions from an active landfill.
- Author
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Kumar, Pramod, Caldow, Christopher, Broquet, Grégoire, Shah, Adil, Laurent, Olivier, Yver-Kwok, Camille, Ars, Sebastien, Defratyka, Sara, Gichuki, Susan W., Lienhardt, Luc, Lozano, Mathis, Paris, Jean-Daniel, Vogel, Felix, Bouchet, Caroline, Allegrini, Elisa, Kelly, Robert, Juery, Catherine, and Ciais, Philippe
- Subjects
GREENHOUSE gases ,LANDFILLS ,DISPERSION (Atmospheric chemistry) ,ATMOSPHERIC methane ,MOLE fraction ,ATMOSPHERIC pressure ,METHANE - Abstract
Landfills are a significant source of fugitive methane (CH
4 ) emissions which should be precisely and regularly monitored to reduce and mitigate net greenhouse gas emissions. In this study, we present long-term in-situ near-surface mobile atmospheric CH4 mole fraction measurements (complemented by meteorological measurements from a fixed station) from 21 campaigns that cover approximately four-years from September 2016 to December 2020. These campaigns were utilized to regularly quantify the total CH4 emissions from an active landfill in France. We use a simple atmospheric inversion approach based on a Gaussian plume dispersion model to derive CH4 emissions. Together with the measurements near the soil surface mainly dedicated to the identification of sources within the landfill, measurements of CH4 made on the landfill perimeter (near-field) helped us to provide some qualitative insights about the respective weight of the main areas of emissions. However, we hardly managed to extract a signal representative of the overall landfill emissions from these measurements, which limited our ability to derive robust estimates of the emissions when assimilating them in the atmospheric inversions. The analysis shows that the inversions based on the measurements from a remote road further away from the landfill (far-field) yielded more reliable estimates. According to these estimates, the total CH4 emissions have a large temporal variability and range from ~0.4 t CH4 /d to ~7 t CH4 /d, with an average value of ~2.1 t CH4 /d. We find a weak negative correlation between these estimates of the CH4 emissions and atmospheric pressure for the active landfill. However, this weak emission-pressure relationship is based on a relatively small sample of reliable emission estimates with large sampling gaps. More frequent robust estimations are required to better understand this relationship for an active landfill. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
44. Deep learning applied to CO2 power plant emissions quantification using simulated satellite images.
- Author
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Dumont Le Brazidec, Joffrey, Vanderbecken, Pierre, Farchi, Alban, Broquet, Grégoire, Kuhlmann, Gerrit, and Bocquet, Marc
- Subjects
DEEP learning ,REMOTE-sensing images ,POWER plants ,GREENHOUSE gases ,CONVOLUTIONAL neural networks ,COAL-fired power plants ,AIR pollutants ,WIND power plants - Abstract
The quantification of emissions of greenhouse gases and air pollutants through the inversion of plumes in satellite images remains a complex problem that current methods can only assess with significant uncertainties. The anticipated launch of the CO
2 M satellite constellation in 2026 is expected to provide high-resolution images of CO2 column-averaged mole fractions (XCO2 ), opening up new possibilities. However, the inversion of future CO2 plumes from CO2 M will encounter various obstacles. A challenge is the CO2 plume low signal-to-noise ratio, due to the variability of the background and instrumental errors in satellite measurements. Moreover, uncertainties in the transport and dispersion processes further complicate the inversion task. To address these challenges, deep learning techniques, such as neural networks, offer promising solutions for retrieving emissions from plumes in XCO2 images. Deep learning models can be trained to identify emissions from plume dynamics simulated using a transport model. It then becomes possible to extract relevant information from new plumes and predict their emissions. In this paper, we employ convolutional neural networks (CNN) to estimate the emission fluxes from a plume in a pseudo XCO2 image. Our dataset used to train and test such methods includes pseudo images based on simulations of hourly XCO2 , NO2 and wind fields near various power plants in Eastern Germany, tracing plumes from anthropogenic and biogenic sources. CNN models are trained to predict emissions from three power plants that exhibit diverse characteristics. The power plants used to assess the deep learning model's performance are not used to train the model. We find that the CNN model outperforms state of the art plume inversion approaches, achieving highly accurate results with an absolute error about half of that of the cross-sectional flux method. Furthermore, we show that our estimations are only slightly affected by the absence of NO2 fields or a detection mechanism as additional information. Finally, interpretability techniques applied to our models confirm that the CNN automatically learns to identify the XCO2 plume and to assess emissions from the plume concentrations. These promising results suggest a high potential of CNNs in estimating local CO2 emissions from satellite images. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
45. New plume comparison metrics for the inversion of passive gases emissions
- Author
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Vanderbecken, Pierre J., primary, Dumont Le Brazidec, Joffrey, additional, Farchi, Alban, additional, Bocquet, Marc, additional, Roustan, Yelva, additional, Potier, Élise, additional, and Broquet, Grégoire, additional
- Published
- 2022
- Full Text
- View/download PDF
46. CarbonCGI road map to observe faint GHG source’s emissions with high resolution observing system
- Author
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Siméoni, Denis, primary, Graziosi, Francesco, additional, Broquet, Grégoire, additional, Kumar, Pramod, additional, Ciais, Philippe, additional, Vergely, Jean Luc, additional, Ferron, Stéphane, additional, Khodnevych, Vitalii, additional, Carlavan, Mikael, additional, Chétrite, Bruno, additional, Tetaz, Nicolas, additional, Delzenne, Christian, additional, Guercio, Nicolas, additional, Boesch, Hartmut, additional, Vogel, Leif, additional, Mariani, Flavio, additional, Windpassinger, Roman, additional, and Sierk, Bernd, additional
- Published
- 2022
- Full Text
- View/download PDF
47. Complementing XCO2 imagery with ground-based CO2 and 14CO2 measurements to monitor CO2 emissions from fossil fuels on a regional to local scale
- Author
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Potier, Elise, primary, Broquet, Grégoire, additional, Wang, Yilong, additional, Santaren, Diego, additional, Berchet, Antoine, additional, Pison, Isabelle, additional, Marshall, Julia, additional, Ciais, Philippe, additional, Bréon, François-Marie, additional, and Chevallier, Frédéric, additional
- Published
- 2022
- Full Text
- View/download PDF
48. Quantifying NOx emissions in Egypt using TROPOMI observations
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Rey-Pommier, Anthony, primary, Chevallier, Frédéric, additional, Ciais, Philippe, additional, Broquet, Grégoire, additional, Christoudias, Theodoros, additional, Kushta, Jonilda, additional, Hauglustaine, Didier, additional, and Sciare, Jean, additional
- Published
- 2022
- Full Text
- View/download PDF
49. Simulated XCO2 images and hotspot plumes formatted for deep learning methods and segmentation models weights
- Author
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Brazidec, Joffrey Dumont Le, Vanderbecken, Pierre, Farchi, Alban, Bocquet, Marc, Jinghui Lian, Broquet, Grégoire, Kuhlmann, Gerrit, Danjou, Alexandre, and Lauvaux, Thomas
- Abstract
Dataset and weights release for preprint "Segmentation of XCO2 images with deep learning: application to synthetic plumes from cities and power plants" Joffrey Dumont Le Brazidec et al.
- Published
- 2022
- Full Text
- View/download PDF
50. Can we use atmospheric CO2 measurements to verify emission trends reported by cities? Lessons from a six-year atmospheric inversion over Paris.
- Author
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Jinghui Lian, Lauvaux, Thomas, Utard, Hervé, Bréon, François-Marie, Broquet, Grégoire, Ramonet, Michel, Laurent, Olivier, Albarus, Ivonne, Chariot, Mali, Kotthaus, Simone, Haeffelin, Martial, Sanchez, Olivier, Perrussel, Olivier, van der Gon, Hugo Anne Denier, Camiel Dellaert, Stijn Nicolaas, and Ciais, Philippe
- Abstract
Existing CO
2 emissions reported by city inventories usually lag real-time by a year or more and are prone to large uncertainties. This study responds to the growing need for timely and precise estimation of urban CO2 emissions to support the present and future mitigation measures and policies. We focus on the Paris metropolitan area, the largest urban region in the European Union and the city with the densest atmospheric CO2 observation network in Europe. We performed long-term atmospheric inversions to quantify the citywide CO2 emissions, both fossil fuel and biogenic sources and sinks, over six years (2016-2021) using a Bayesian inverse modeling system. Our inversion framework benefits from a novel near-real-time hourly fossil fuel CO2 emission inventory (Origins.earth) at 1 km spatial resolution. In addition to the mid-afternoon observations, we attempt to assimilate morning CO2 concentrations based on the ability of the WRF-Chem transport model to simulate atmospheric boundary layer dynamics constrained by observed layer heights. Our results show a long-term decreasing trend by around 2% per year in annual CO2 emissions over the Paris region. The impact of COVID-19 pandemic led to a 13%±1% reduction in annual fossil fuel CO2 emissions in 2020 with respect to 2019. Then, annual emissions increased by 5.2% from 32.6±2.2 MtCO2 in 2020 to 34.3±2.3 MtCO2 in 2021. Based on a combination of up-to-date inventories, high-resolution atmospheric modeling, and highprecision observations, our current capacity could deliver near real-time CO2 emission estimates at city scale in less than a month, and the results agree within 10% with independent estimates from multiple city-scale inventories. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
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