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259 results on '"Vrekoussis, Mihalis"'

4. Submicron aerosol pollution in Greater Cairo (Egypt): A new type of urban haze?

Author

Christodoulou, Aliki, Bezantakos, Spyros, Bourtsoukidis, Efstratios, Stavroulas, Iasonas, Pikridas, Michael, Oikonomou, Konstantina, Iakovides, Minas, Hassan, Salwa K., Boraiy, Mohamed, El-Nazer, Mostafa, Wheida, Ali, Abdelwahab, Magdy, Sarda-Estève, Roland, Rigler, Martin, Biskos, Giorgos, Afif, Charbel, Borbon, Agnes, Vrekoussis, Mihalis, Mihalopoulos, Nikos, Sauvage, Stéphane, and Sciare, Jean

Published
2024
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9. Proportional relationships between carbonaceous aerosols and trace gases in city plumes of Europe and East Asia

Author

Deroubaix, Adrien, primary, Vountas, Marco, additional, Gaubert, Benjamin, additional, Andrés Hernández, Maria Dolores, additional, Borrmann, Stephan, additional, Brasseur, Guy, additional, Holanda, Bruna, additional, Kanaya, Yugo, additional, Kaiser, Katharina, additional, Kluge, Flora, additional, Krüger, Ovid Oktavian, additional, Labuhn, Inga, additional, Lichtenstern, Michael, additional, Pfeilsticker, Klaus, additional, Pöhlker, Mira, additional, Schlager, Hans, additional, Schneider, Johannes, additional, Siour, Guillaume, additional, Swain, Basudev, additional, Tuccella, Paolo, additional, Vinjamuri, Kameswara S., additional, Vrekoussis, Mihalis, additional, Weyland, Benjamin, additional, and Burrows, John P., additional

Published
2024
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10. The Unmanned Systems Research Laboratory (USRL): A New Facility for UAV-Based Atmospheric Observations

Author

Kezoudi, Maria, Keleshis, Christos, Antoniou, Panayiota, Biskos, George, Bronz, Murat, Constantinides, Christos, Desservettaz, Maximillien, Gao, Ru-Shan, Girdwood, Joe, Harnetiaux, Jonathan, Kandler, Konrad, Leonidou, Andreas, Liu, Yunsong, Lelieveld, Jos, Marenco, Franco, Mihalopoulos, Nikos, Močnik, Griša, Neitola, Kimmo, Paris, Jean-Daniel, Pikridas, Michael, Sarda-Esteve, Roland, Stopford, Chris, Unga, Florin, Vrekoussis, Mihalis, Sciare, Jean, Kezoudi, Maria, Keleshis, Christos, Antoniou, Panayiota, Biskos, George, Bronz, Murat, Constantinides, Christos, Desservettaz, Maximillien, Gao, Ru-Shan, Girdwood, Joe, Harnetiaux, Jonathan, Kandler, Konrad, Leonidou, Andreas, Liu, Yunsong, Lelieveld, Jos, Marenco, Franco, Mihalopoulos, Nikos, Močnik, Griša, Neitola, Kimmo, Paris, Jean-Daniel, Pikridas, Michael, Sarda-Esteve, Roland, Stopford, Chris, Unga, Florin, Vrekoussis, Mihalis, and Sciare, Jean

Abstract

The Unmanned Systems Research Laboratory (USRL) of the Cyprus Institute is a new mobile exploratory platform of the EU Research Infrastructure Aerosol, Clouds and Trace Gases Research InfraStructure (ACTRIS). USRL offers exclusive Unmanned Aerial Vehicle (UAV)-sensor solutions that can be deployed anywhere in Europe and beyond, e.g., during intensive field campaigns through a transnational access scheme in compliance with the drone regulation set by the European Union Aviation Safety Agency (EASA) for the research, innovation, and training. UAV sensor systems play a growing role in the portfolio of Earth observation systems. They can provide cost-effective, spatial in-situ atmospheric observations which are complementary to stationary observation networks. They also have strong potential for calibrating and validating remote-sensing sensors and retrieval algorithms, mapping close-to-the-ground emission point sources and dispersion plumes, and evaluating the performance of atmospheric models. They can provide unique information relevant to the short- and long-range transport of gas and aerosol pollutants, radiative forcing, cloud properties, emission factors and a variety of atmospheric parameters. Since its establishment in 2015, USRL is participating in major international research projects dedicated to (1) the better understanding of aerosol-cloud interactions, (2) the profiling of aerosol optical properties in different atmospheric environments, (3) the vertical distribution of air pollutants in and above the planetary boundary layer, (4) the validation of Aeolus satellite dust products by utilizing novel UAV-balloon-sensor systems, and (5) the chemical characterization of ship and stack emissions. A comprehensive overview of the new UAV-sensor systems developed by USRL and their field deployments is presented here. This paper aims to illustrate the strong scientific potential of UAV-borne measurements in the atmospheric sciences and the need for their integratio

Published
2024

12. Assessing the global contribution of marine, terrestrial bioaerosols, and desert dust to ice-nucleating particle concentrations.

Author

Chatziparaschos, Marios, Myriokefalitakis, Stelios, Kalivitis, Nikos, Daskalakis, Nikos, Nenes, Athanasios, Ageitos, María Gonçalves, Costa-Surós, Montserrat, Pérez García-Pando, Carlos, Vrekoussis, Mihalis, and Kanakidou, Maria

Abstract

Aerosol-cloud interactions, and particularly ice crystals in mixed-phase clouds (MPC), stand as a key source of uncertainty in climate change assessments. State-of-the-art laboratory-based parameterizations were introduced into a global chemistry-transport model to investigate the contribution of mineral dust, marine primary organic aerosol (MPOA), and terrestrial primary biological aerosol particles (PBAP) to ice nucleating particles (INP) in MPC. INP originating from PBAP (INPPBAP) are found to be the primary source of INP at low altitudes between -10°C and -20°C, particularly in the tropics, with a pronounced peak in the Northern Hemisphere (NH) during boreal summer. INPPBAP contributes about 27% (in the NH) and 30% (in the SH) of the INP population. Dust-derived INP (INPD) show a prominent presence at high altitudes in all seasons, dominating at temperatures below -25°C, constituting 68% of the INP average column burden. MPOA-derived INP (INPMPOA) dominate in the Southern Hemisphere (SH), particularly at subpolar and polar latitudes at low altitudes for temperatures below -16°C, representing approximately 46% of INP population in the SH. When evaluated against available global observational INP data, the model achieves its highest predictability across all temperature ranges when both INPD and INPMPOA are included. The additional introduction of INPPBAP slightly reduces model skills for temperatures lower than -16oC; however, INPPBAP are the main contributors to warm-temperature ice nucleation events. Therefore, consideration of dust and marine and terrestrial bioaerosol as INP precursors is required to simulate ice nucleation in climate models. In this respect, emissions, ice-nucleating activity of each particle type and its evolution during atmospheric transport require further investigations. [ABSTRACT FROM AUTHOR]

Published
2024
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13. The Atmospheric Oxidizing Capacity in China: Part 2. Sensitivity to emissions of primary pollutants.

Author

Dai, Jianing, Brasseur, Guy P., Vrekoussis, Mihalis, Kanakidou, Maria, Qu, Kun, Zhang, Yijuan, Zhang, Hongliang, and Wang, Tao

Subjects
PHOTOCHEMICAL smog, POLLUTANTS, AIR pollutants, GREENHOUSE gas mitigation, VOLATILE organic compounds, CHEMICAL models, NITROGEN oxides, RADICALS (Chemistry)
Abstract

The Atmospheric Oxidation Capacity (AOC), often referred to as the self-cleansing ability of the atmosphere, considerably affects the concentrations of photochemical air pollutants. Despite substantial reductions in anthropogenic emissions of key chemical compounds in China, the mechanisms that determine the changes in the atmospheric oxidation capacity are still not sufficiently understood. Here, a regional chemical transport model is employed to quantify the sensitivity of air pollutants and photochemical parameters to specified emission reductions in China for conditions of January and July 2018 as representative. The model simulations show that, in winter, a 50 % decrease in nitrogen oxides (NOx) emissions leads to an 8–10 ppbv (15–20 %) increase in surface ozone concentrations across China. In summer, the ozone concentration decreases by 2–8 ppbv (3–12 %) in NOx-limited areas, while ozone increases by up to 12 ppbv (15 %) in volatile organic compounds (VOCs)-limited areas. This ozone increase is associated with a reduced NOx-titration effect and higher levels of hydroperoxyl (HO2) radical due to decreased aerosol uptake. With an additional 50 % reduction in anthropogenic VOCs emission, the predicted ozone concentration decreases by 5–12 ppbv (6–15 %) in the entire geographic area of China, with an exception in the areas, where the role of BVOCs is crucial to ozone formation. Further, the adopted reduction in NOx emission leads to an increase of AOC by 18 % in VOC-limited areas. This specific increase is associated with the combined effect of enhanced radical cycles associated with the photolysis of oxidized VOCs (OVOCs) and the oxidation of alkenes by hydroxyl (OH) radical and O3. A large reduction of daytime AOC in summer results from the reduction in anthropogenic VOCs emission, with a dominant contribution from the reaction of OH radical with reduced alkenes, followed by the reactions with depleted aromatics and OVOCs. This study highlights that photolysis of OVOCs and oxidation of alkenes in urban areas when NOx emission is reduced leads to an increase in O3. To mitigate ozone rises in urban areas, a joint reduction in the emission of NOx and specific VOCs species, including alkenes and aromatics and photodegradable OVOCs, should be implemented. [ABSTRACT FROM AUTHOR]

Published
2024
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15. Rethinking the role of transport and photochemistry in regional ozone pollution: insights from ozone concentration and mass budgets

Author

Qu, Kun, Wang, Xuesong, Cai, Xuhui, Yan, Yu, Jin, Xipeng, Vrekoussis, Mihalis, Kanakidou, Maria, Brasseur, Guy P., Shen, Jin, Xiao, Teng, Zeng, Limin, and Zhang, Yuanhang

Abstract

Understanding the role of transport and photochemistry is essential to mitigate tropospheric ozone (O3) pollution within a region. In previous studies, the O3 concentration budget has been widely used to determine the contributions of two processes to the variations of O3 concentrations. These studies often conclude that local photochemistry is the main cause of regional O3 pollution; however, they fail to explain why O3 in a targeted region is often primarily derived from O3 and/or its precursors transported from the outside regions, as reported by many studies of O3 source apportionment. Here, we present a method to calculate the hourly contributions of O3-related processes to the variations of not only the mean O3 concentration but also the total O3 mass (the corresponding budgets are noted as the O3 concentration and mass budget, respectively) within the atmospheric boundary layer (ABL) of the concerned region. Based on the modelling results of WRF-CMAQ (Weather Research and Forecasting and Community Multiscale Air Quality), the two O3 budgets were applied to comprehensively understand the effects of transport and photochemistry on the O3 pollution over the Pearl River Delta (PRD) region in China. Quantified results demonstrate the different role of transport and photochemistry when comparing the two O3 budgets: photochemistry drives the rapid increase of O3 concentrations during the day, whereas transport, especially vertical exchange through the ABL top, controls both rapid O3 mass increase in the morning and decrease in the afternoon. The diurnal changes of the transport contributions in the two O3 budgets highlight the influences of the ABL diurnal cycle and regional wind fields on regional O3 pollution. Through high contributions to the O3 mass increase in the morning, transport determines that most O3 in the PRD originates from the global background and emissions outside the region. However, due to the simultaneous rapid increase of ABL volumes, this process only has a relatively limited effect on O3 concentration increase compared to photochemistry, and transport effect on the regional sources of O3 cannot be illustrated by the O3 concentration budget. For future studies targeting O3 and other secondary pollutants with moderately long atmospheric lifetimes (e.g. fine particulate matter and some of its components), insights from both concentration and mass budgets are required to fully understand the role of transport, chemistry and other related processes.

Published
2023

16. A multi-model study on the impacts of continuous volcanic activity on air quality in the surrounding communities

Author

Poulidis, Alexandros, Takishita, Kosei, Iguchi, Masato, and Vrekoussis, Mihalis

Abstract

Chemistry modelling can be employed to study regional air quality and inform mitigation strategies. To accurately represent air quality, realistic emission data for all natural and anthropogenic sources need to be supplied. Volcanic emissions represent a significant challenge, due to their unpredictable nature. As a result, only a small number of volcanoes are included in emission datasets, focusing only SO2, despite the potential release of micron-scale volcanic ash that can affect particulate matter (PM) concentrations. These emissions can be especially important in the case of volcanoes with long periods of passive emissions and intermittent eruptions, as in the case of Sakurajima volcano in southern Japan. Due to its high level of activity since 1955 and the large nearby population, Sakurajima is one of the most closely-monitored volcanoes in the world. The permanent deployment of equipment such as tiltmeters and tephra collectors has allowed for the accurate estimation of volcanic ash emissions, giving us the unique opportunity to provide realistic input data for air quality modelling. Emissions were simulated using two models: WRF-chem, a chemistry model, and FALL3D a volcanic emission transport model. Simulations are carried out for 2019, covering anthropogenic, biomass burning and non-volcanogenic natural emissions (WRF-chem) and volcanic emissions (FALL3D), with results validated against daily surface observations of airborne concentrations (PM and SO2) and monthly ashfall values within the Kagoshima prefecture. Overall, results provide the first direct comparison of the ratio between volcanogenic and non-volcanogenic emissions and confirm the importance of the former., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023

17. Investigating the Link Between Glyoxal and Biogenic Activities

Author

Alvarado, Leonardo M. A., Richter, Andreas, Vrekoussis, Mihalis, Wittrock, Folkard, Hilboll, Andreas, Schreier, Stefan F., Burrows, John P., Blondel, Philippe, Series editor, Guilyardi, Eric, Series editor, Rabassa, Jorge, Series editor, Horwood, Clive, Series editor, Lohmann, Gerrit, editor, Meggers, Helge, editor, Unnithan, Vikram, editor, Wolf-Gladrow, Dieter, editor, Notholt, Justus, editor, and Bracher, Astrid, editor

Published
2015
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20. National CO2 budgets (2015–2020) inferred from atmospheric CO2 observations in support of the global stocktake

Author

Byrne, Brendan, primary, Baker, David F., additional, Basu, Sourish, additional, Bertolacci, Michael, additional, Bowman, Kevin W., additional, Carroll, Dustin, additional, Chatterjee, Abhishek, additional, Chevallier, Frédéric, additional, Ciais, Philippe, additional, Cressie, Noel, additional, Crisp, David, additional, Crowell, Sean, additional, Deng, Feng, additional, Deng, Zhu, additional, Deutscher, Nicholas M., additional, Dubey, Manvendra K., additional, Feng, Sha, additional, García, Omaira E., additional, Griffith, David W. T., additional, Herkommer, Benedikt, additional, Hu, Lei, additional, Jacobson, Andrew R., additional, Janardanan, Rajesh, additional, Jeong, Sujong, additional, Johnson, Matthew S., additional, Jones, Dylan B. A., additional, Kivi, Rigel, additional, Liu, Junjie, additional, Liu, Zhiqiang, additional, Maksyutov, Shamil, additional, Miller, John B., additional, Miller, Scot M., additional, Morino, Isamu, additional, Notholt, Justus, additional, Oda, Tomohiro, additional, O'Dell, Christopher W., additional, Oh, Young-Suk, additional, Ohyama, Hirofumi, additional, Patra, Prabir K., additional, Peiro, Hélène, additional, Petri, Christof, additional, Philip, Sajeev, additional, Pollard, David F., additional, Poulter, Benjamin, additional, Remaud, Marine, additional, Schuh, Andrew, additional, Sha, Mahesh K., additional, Shiomi, Kei, additional, Strong, Kimberly, additional, Sweeney, Colm, additional, Té, Yao, additional, Tian, Hanqin, additional, Velazco, Voltaire A., additional, Vrekoussis, Mihalis, additional, Warneke, Thorsten, additional, Worden, John R., additional, Wunch, Debra, additional, Yao, Yuanzhi, additional, Yun, Jeongmin, additional, Zammit-Mangion, Andrew, additional, and Zeng, Ning, additional

Published
2023
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21. Global sensitivity analysis of a one-dimensional ocean biogeochemical model

Author

Mamnun, Nabir, Völker, Christoph, Krumscheid, Sebastian, Vrekoussis, Mihalis, Nerger, Lars, Mamnun, Nabir, Völker, Christoph, Krumscheid, Sebastian, Vrekoussis, Mihalis, and Nerger, Lars

Abstract

Ocean biogeochemical (BGC) models are a powerful tool for investigating ocean biogeochemistry and the global carbon cycle. The potential benefits emanating from BGC simulations and predictions are broad, with significant societal impacts from fisheries management to carbon dioxide removal and policy-making. These models contain numerous parameters, each coupled with large uncertainties, leading to significant uncertainty in the model outputs. This study performs a global sensitivity analysis (GSA) of an ocean BGC model to identify the uncertain parameters that impact the variability of model outputs most. The BGC model Regulated Ecosystem Model 2 is used in a one-dimensional configuration at two ocean sites in the North Atlantic (BATS) and the Mediterranean Sea (DYFAMED). Variance-based Sobol' indices are computed to identify the most influential parameters for each site for the quantities of interest (QoIs) commonly considered for the calibration and validation of BGC models. The most sensitive parameters are the chlorophyll to nitrogen ratio, chlorophyll degradation rate, zooplankton grazing and excretion parameters, photosynthesis parameters, and nitrogen and carbon remineralization rate. Overall, the sensitivities of most QoIs were similar across the two sites; however, some differences emerged because of different mixed layer depths. The results suggest that implementing multiple zooplankton function types in BGC models can improve BGC predictions. Further, explicitly implementing heterotrophic bacteria in the model can better simulate the carbon export production and CO2 fluxes. The study offers a comprehensive list of the most important BGC parameters that need to be quantified for future modeling applications and insights for BGC model developments.

Published
2023

23. Retrieval of greenhouse gases from GOSAT and GOSAT-2 using the FOCAL algorithm

Author

Noël, Stefan, Reuter, Maximilian, Buchwitz, Michael, Borchardt, Jakob, Hilker, Michael, Schneising, Oliver, Bovensmann, Heinrich, Burrows, John P., Di Noia, Antonio, Parker, Robert J., Suto, Hiroshi, Yoshida, Yukio, Buschmann, Matthias, Deutscher, Nicholas M., Feist, Dietrich G., Griffith, David W. T., Hase, Frank, Kivi, Rigel, Liu, Cheng, Morino, Isamu, Notholt, Justus, Oh, Young-Suk, Ohyama, Hirofumi, Petri, Christof, Pollard, David F., Rettinger, Markus, Roehl, Coleen M., Rousogenous, Constantina, Sha, Mahesh K., Shiomi, Kei, Strong, Kimberly, Sussmann, Ralf, Té, Yao, Velazco, Voltaire A., Vrekoussis, Mihalis, and Warneke, Thorsten

Subjects
remote sensing, GOSAT-2, FOCAL, Earth sciences, Atmospheric Science, CH4, Satellite, TCCON, ddc:550, CO2, retrieval, GOSAT
Abstract

We show new results from an updated version of the Fast atmOspheric traCe gAs retrievaL (FOCAL) retrieval method applied to measurements of the Greenhouse gases Observing SATellite (GOSAT) and its successor GOSAT-2. FOCAL was originally developed for estimating the total column carbon dioxide mixing ratio (XCO2) from spectral measurements made by the Orbiting Carbon Observatory-2 (OCO-2). However, depending on the available spectral windows, FOCAL also successfully retrieves total column amounts for other atmospheric species and their uncertainties within one single retrieval. The main focus of the current paper is on methane (XCH4; full-physics and proxy product), water vapour (XH2O) and the relative ratio of semi-heavy water (HDO) to water vapour (δD). Due to the extended spectral range of GOSAT-2, it is also possible to derive information on carbon monoxide (XCO) and nitrous oxide (XN2O) for which we also show first results. We also present an update on XCO2 from both instruments. For XCO2, the new FOCAL retrieval (v3.0) significantly increases the number of valid data compared with the previous FOCAL retrieval version (v1) by 50 % for GOSAT and about a factor of 2 for GOSAT-2 due to relaxed pre-screening and improved post-processing. All v3.0 FOCAL data products show reasonable spatial distribution and temporal variations. Comparisons with the Total Carbon Column Observing Network (TCCON) result in station-to-station biases which are generally in line with the reported TCCON uncertainties. With this updated version of the GOSAT-2 FOCAL data, we provide a first total column average XN2O product. Global XN2O maps show a gradient from the tropics to higher latitudes on the order of 15 ppb, which can be explained by variations in tropopause height. The new GOSAT-2 XN2O product compares well with TCCON. Its station-to-station variability is lower than 2 ppb, which is about the magnitude of the typical N2O variations close to the surface. However, both GOSAT-2 and TCCON measurements show that the seasonal variations in the total column average XN2O are on the order of 8 ppb peak-to-peak, which can be easily resolved by the GOSAT-2 FOCAL data. Noting that only few XN2O measurements from satellites exist so far, the GOSAT-2 FOCAL product will be a valuable contribution in this context.

Published
2023

24. The atmospheric oxidizing capacity in China – Part 1: Roles of different photochemical processes.

Author

Dai, Jianing, Brasseur, Guy P., Vrekoussis, Mihalis, Kanakidou, Maria, Qu, Kun, Zhang, Yijuan, Zhang, Hongliang, and Wang, Tao

Subjects
AIR pollutants, PEROXY radicals, CHEMICAL models, HYDROXYL group, METEOROLOGICAL research
Abstract

Atmospheric oxidation capacity (AOC) characterizes the ability of the atmosphere to scavenge air pollutants. However, the processes involved in China, where anthropogenic emissions have changed dramatically in the past decade, are not fully understood. A detailed analysis of different parameters that determine the AOC in China is presented on the basis of numerical simulations performed with the regional chemical–meteorological Weather Research and Forecasting model with Chemistry (WRF-Chem). The model shows that the aerosol effects related to extinction and heterogeneous processes produce a decrease in surface ozone of approximately 8–10 ppbv in NO x -limited rural areas and an increase of 5–10 ppbv in VOC-limited urban areas. In this latter case, the ozone increase is noticeable for aerosol concentrations ranging from 20 to 45 µ g m -3 in July 2018. The ozone reduction in NO x -sensitive regions is due to the combined effect of nitrogen dioxide and peroxy radical uptake on particles and of the light extinction by aerosols, which affects the photodissociation rates. The ozone increase in VOC-sensitive areas is attributed to the uptake of NO 2 by aerosols, which is offset by the reduced ozone formation associated with HO 2 uptake and with aerosol extinction. Our study concludes that more than 90 % of the daytime AOC is due to the reaction of the hydroxyl radical with VOCs and carbon monoxide. In urban areas, during summertime, the main contributions to daytime AOC are the reactions of OH with alkene (30 %–50 %), oxidized volatile organic compounds (OVOCs) (33 %–45 %), and carbon monoxide (20 %–45 %). In rural areas, the largest contribution results from the reaction of OH with alkenes (60 %). Nocturnal AOC is dominantly attributed to the reactions with the nitrate radical (50 %–70 %). Our results shed light on the contribution of aerosol-related NO x loss and the high reactivity of alkenes for photochemical pollution. With the reduction in aerosols and anthropogenic ozone precursors, the chemistry of nitrogen and temperature-sensitive VOCs will become increasingly important. More attention needs to be paid to the role of photodegradable OVOCs and nocturnal oxidants in the formation of secondary pollutants. [ABSTRACT FROM AUTHOR]

Published
2023
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28. The temperature sensitivity of mono- and sesquiterpene emissions from terrestrial vegetation: Insights from a meta-analysis 

Author

Bourtsoukidis, Efstratios, primary, Pozzer, Andrea, additional, Williams, Jonathan, additional, Makowski, David, additional, Peñuelas, Josep, additional, Matthaios, Vasileios, additional, Economou, Theo, additional, Lazoglou, Georgia, additional, Yañez-Serrano, Ana Maria, additional, Nölscher, Anke, additional, Lelieveld, Jos, additional, Ciais, Philippe, additional, Vrekoussis, Mihalis, additional, Daskalakis, Nikos, additional, and Sciare, Jean, additional

Published
2023
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30. Submicron Aerosol Pollution in Greater Cairo (Egypt): A New Type of Urban Haze?

Author

Christodoulou, Aliki, primary, Bezantakos, Spyros, additional, Bourtsoukidis, Efstratios, additional, Stavroulas, Iasonas, additional, Pikridas, Michael, additional, Oikonomou, Konstantina, additional, Iakovides, Minas, additional, Hassan, Salwa K., additional, Boraiy, Mohamed, additional, El-Nazer, Mostafa, additional, Wheida, Ali, additional, Abdel Wahab, Magdy, additional, Sarda-Estève, Roland, additional, Rigler, Martin, additional, Biskos, Giorgos, additional, Afif, Charbel, additional, Borbon, Agnes, additional, Vrekoussis, Mihalis, additional, Mihalopoulos, Nikos, additional, Sauvage, Stéphane, additional, and Sciare, Jean, additional

Published
2023
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32. High temperature sensitivity of monoterpene emissions from global vegetation

Author

Bourtsoukidis, Efstratios, primary, Pozzer, Andrea, additional, Williams, Jonathan, additional, Makowski, David, additional, Penuelas, Josep, additional, Matthaios, Vaseilios, additional, Lazoglou, Georgia, additional, Yañez-Serrano, Ana, additional, Ciais, Philippe, additional, Lelieveld, Jos, additional, Vrekoussis, Mihalis, additional, Daskalakis, Nikolaos, additional, and Sciare, Jean, additional

Published
2022
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35. National CO2 budgets (2015–2020) inferred from atmospheric CO2 observations in support of the global stocktake

Author

Byrne, Brendan, Baker, David F., Basu, Sourish, Bertolacci, Michael, Bowman, Kevin W., Carroll, Dustin, Chatterjee, Abhishek, Chevallier, Frédéric, Ciais, Philippe, Cressie, Noel, Crisp, David, Crowell, Sean, Deng, Feng, Deng, Zhu, Deutscher, Nicholas Michael, Dubey, Manvendra K., Feng, Sha, García Rodríguez, Omaira Elena, Griffith, David W. T., Herkommer, Benedikt, Hu, Lei, Jacobson, Andrew R., Janardanan, Rajesh, Jeong, Sujong, Johnson, Matthew S., Jones, Dylan B. A., Kivi, Rigel, Liu, Junjie, Liu, Zhiqiang, Maksyutov, Shamil, Miller, John B., Morino, Isamu, Notholt, Justus, Oda, Tomohiro, O'Dell, Christopher, Oh, Young-Suk, Ohyama, Hirofumi, Patra, Prabir K., Peiro, Hélène, Petri, Christof, Philip, Sajeev, Pollard, David F., Poulter, Benjamin, Remaud, Marine, Schuh, Andrew, Sha, Mahesh Kumar, Shiomi, Kei, Strong, Kimberly, Sweeney, Colm, Te, Yao, Tian, Hanqin, Velazco, Voltaire A., Vrekoussis, Mihalis, Warneke, Thorsten, Worden, John, Wunch, Debra, Yao, Yuamzhi, Yun, Jeongmin, Zammit Mangion, Andrew, and Zeng, Ning

Subjects
Temperature increase, Carbon dioxide emission, Climate change
Abstract

Accurate accounting of emissions and removals of CO2 is critical for the planning and verification of emission reduction targets in support of the Paris Agreement. Here, we present a pilot dataset of country-specific net carbon exchange (NCE; fossil plus terrestrial ecosystem fluxes) and terrestrial carbon stock changes aimed at informing countries’ carbon budgets. These estimates are based on “top-down” NCE outputs from the v10 Orbiting Carbon Observatory (OCO-2) modeling intercomparison project (MIP), wherein an ensemble of inverse modeling groups conducted standardized experiments assimilating OCO-2 column-averaged dry-air mole fraction (XCO2 ) retrievals (ACOS v10), in situ CO2 measurements or combinations of these data. The v10 OCO-2 MIP NCE estimates are combined with “bottom-up” estimates of fossil fuel emissions and lateral carbon fluxes to estimate changes in terrestrial carbon stocks, which are impacted by anthropogenic and natural drivers. These flux and stock change estimates are reported annually (2015–2020) as both a global 1◦ × 1 ◦ gridded dataset and a country-level dataset and are available for download from the Committee on Earth Observation Satellites’ (CEOS) website: https://doi.org/10.48588/npf6-sw92 (Byrne et al., 2022). Across the v10 OCO-2 MIP experiments, we obtain increases in the ensemble median terrestrial carbon stocks of 3.29–4.58 PgCO2 yr−1 (0.90–1.25 PgC yr−1 ). This is a result of broad increases in terrestrial carbon stocks across the northern extratropics, while the tropics generally have stock losses but with considerable regional variability and differences between v10 OCO-2 MIP experiments. We discuss the state of the science for tracking emissions and removals using top-down methods, including current limitations and future developments towards top-down monitoring and verification systems. This research has been supported by the European Commission, Horizon 2020 Framework Programme (CoCO2 (grant no. 958927 856612/EMME-CARE)) and Copernicus Atmosphere Monitoring Service (grant no. CAMS73), the Australian Research Council (grant nos. DP190100180, DE180100203, DP160100598, LE0668470, DP140101552, DP110103118, DP0879468 and FT180100327), the Environmental Restoration and Conservation Agency (grant no. JPMEERF21S20800), the Korea Meteorological Administration (grant no. KMA2018-00320), the National Aeronautics and Space Administration (grant nos. 20-OCOST20-0004, 80NSSC18K0908, 80NSSC18K0976, 80NSSC20K0006, 80NSSC21K1068, 80NSSC21K1073, 80NSSC21K1077, 80NSSC21K1080, 80HQTR21T0069, NAG512247, NNG05GD07G, NNH17ZDA001N-OCO2 and NNX15AG93G), and the National Oceanic and Atmospheric Administration (grant no. NA18OAR4310266).

Published
2023

36. Uncertainties in ocean biogeochemical simulations: Application of ensemble data assimilation to a one-dimensional model

Author

Mamnun, Nabir, Völker, Christoph, Vrekoussis, Mihalis, and Nerger, Lars

Subjects
Global and Planetary Change, Ocean Engineering, Aquatic Science, Oceanography, Water Science and Technology
Abstract

Marine biogeochemical (BGC) models are highly uncertain in their parameterization. The value of the BGC parameters are poorly known and lead to large uncertainties in the model outputs. This study focuses on the uncertainty quantification of model fields and parameters within a one-dimensional (1-D) ocean BGC model applying ensemble data assimilation. We applied an ensemble Kalman filter provided by the Parallel Data Assimilation Framework (PDAF) into a 1-D vertical configuration of the BGC model Regulated Ecosystem Model 2 (REcoM2) at two BGC time-series stations: the Bermuda Atlantic Time-series Study (BATS) and the Dynamique des Flux Atmosphériques en Méditerranée (DYFAMED). We assimilated 5-day satellite chlorophyll-a (chl-a) concentration and monthly in situ net primary production (NPP) data for 3 years to jointly estimate 10 preselected key BGC parameters and the model state. The estimated set of parameters resulted in improvements in the model prediction up to 66% for the surface chl-a and 56% for NPP. Results show that assimilating satellite chl-a concentration data alone degraded the prediction of NPP. Simultaneous assimilation of the satellite chl-a data and in situ NPP data improved both surface chl-a and NPP simulations. We found that correlations between parameters preclude estimating parameters independently. Co-dependencies between parameters also indicate that there is not a unique set of optimal parameters. Incorporation of proper uncertainty estimation in BGC predictions, therefore, requires ensemble simulations with varying parameter values.

Published
2022
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38. Long-range transported pollution from the Middle East and its impact on carbonaceous aerosol sources over Cyprus

Author

Christodoulou, Aliki, primary, Stavroulas, Iasonas, additional, Vrekoussis, Mihalis, additional, Desservettaz, Maximillien, additional, Pikridas, Michael, additional, Bimenyimana, Elie, additional, Ivančič, Matic, additional, Rigler, Martin, additional, Goloub, Philippe, additional, Oikonomou, Konstantina, additional, Sarda-Estève, Roland, additional, Savvides, Chrysanthos, additional, Afif, Charbel, additional, Mihalopoulos, Nikos, additional, Sauvage, Stéphane, additional, and Sciare, Jean, additional

Published
2022
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39. Supplementary material to "Long-range transported pollution from the Middle East and its impact on carbonaceous aerosol sources over Cyprus"

Author

Christodoulou, Aliki, primary, Stavroulas, Iasonas, additional, Vrekoussis, Mihalis, additional, Desservettaz, Maximillien, additional, Pikridas, Michael, additional, Bimenyimana, Elie, additional, Ivančič, Matic, additional, Rigler, Martin, additional, Goloub, Philippe, additional, Oikonomou, Konstantina, additional, Sarda-Estève, Roland, additional, Savvides, Chrysanthos, additional, Afif, Charbel, additional, Mihalopoulos, Nikos, additional, Sauvage, Stéphane, additional, and Sciare, Jean, additional

Published
2022
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40. Ambient carbonaceous aerosol levels in Cyprus and the role of pollution transport from the Middle East.

Author

Christodoulou, Aliki, Stavroulas, Iasonas, Vrekoussis, Mihalis, Desservettaz, Maximillien, Pikridas, Michael, Bimenyimana, Elie, Kushta, Jonilda, Ivančič, Matic, Rigler, Martin, Goloub, Philippe, Oikonomou, Konstantina, Sarda-Estève, Roland, Savvides, Chrysanthos, Afif, Charbel, Mihalopoulos, Nikos, Sauvage, Stéphane, and Sciare, Jean

Subjects
CARBONACEOUS aerosols, POLLUTION, CHEMICAL properties, AIR masses, MATRIX decomposition, FOSSIL fuels
Abstract

The geographical origin and source apportionment of submicron carbonaceous aerosols (organic aerosols, OAs, and black carbon, BC) have been investigated here for the first time, deploying high time-resolution measurements at an urban background site of Nicosia, the capital city of Cyprus, in the eastern Mediterranean. This study covers a half-year period, encompassing both the cold and warm periods with continuous observations of the physical and chemical properties of PM 1 performed with an Aerosol Chemical Speciation Monitor (ACSM), an aethalometer, accompanied by a suite of various ancillary offline and online measurements. Carbonaceous aerosols were dominant during both seasons (cold and warm periods), with a contribution of 57 % and 48 % to PM 1 , respectively, and exhibited recurrent intense nighttime peaks (> 20–30 µ g m -3) during the cold period, associated with local domestic heating. The findings of this study show that high concentrations of sulfate (close to 3 µ g m -3) were continuously recorded, standing among the highest ever reported for Europe and originating from the Middle East region. Source apportionment of the OA and BC fractions was performed using the positive matrix factorization (PMF) approach and the combination of two models (aethalometer model and multilinear regression), respectively. Our study revealed elevated hydrocarbon-like organic aerosol (HOA) concentrations in Nicosia (among the highest reported for a European urban background site), originating from a mixture of local and regional fossil fuel combustion sources. Although air masses from the Middle East had a low occurrence and were observed mostly during the cold period, they were shown to strongly affect the mean concentrations levels of BC and OA in Nicosia during both seasons. Overall, the present study brings to our attention the need to further characterize primary and secondary carbonaceous aerosols in the Middle East, an undersampled region characterized by continuously increasing fossil fuel (oil and gas) emissions and extreme environmental conditions, which can contribute to photochemical ageing. [ABSTRACT FROM AUTHOR]

Published
2023
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41. Supplementary material to "Role of K-feldspar and quartz in global ice nucleation by mineral dust in mixed-phase clouds"

Author

Chatziparaschos, Marios, primary, Daskalakis, Nikos, additional, Myriokefalitakis, Stelios, additional, Kalivitis, Nikos, additional, Nenes, Athanasios, additional, Gonçalves Ageitos, Maria, additional, Costa-Surós, Montserrat, additional, Pérez García-Pando, Carlos, additional, Zanoli, Medea, additional, Vrekoussis, Mihalis, additional, and Kanakidou, Maria, additional

Published
2022
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42. Role of K-feldspar and quartz in global ice nucleation by mineral dust in mixed-phase clouds

Author

Chatziparaschos, Marios, primary, Daskalakis, Nikos, additional, Myriokefalitakis, Stelios, additional, Kalivitis, Nikos, additional, Nenes, Athanasios, additional, Gonçalves Ageitos, Maria, additional, Costa-Surós, Montserrat, additional, Pérez García-Pando, Carlos, additional, Zanoli, Medea, additional, Vrekoussis, Mihalis, additional, and Kanakidou, Maria, additional

Published
2022
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43. Improvements of a low-cost CO2 commercial nondispersive near-infrared (NDIR) sensor for unmanned aerial vehicle (UAV) atmospheric mapping applications

Author

Liu, Yunsong, primary, Paris, Jean-Daniel, additional, Vrekoussis, Mihalis, additional, Antoniou, Panayiota, additional, Constantinides, Christos, additional, Desservettaz, Maximilien, additional, Keleshis, Christos, additional, Laurent, Olivier, additional, Leonidou, Andreas, additional, Philippon, Carole, additional, Vouterakos, Panagiotis, additional, Quéhé, Pierre-Yves, additional, Bousquet, Philippe, additional, and Sciare, Jean, additional

Published
2022
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44. Chemical and dynamical identification of emission outflows during the HALO campaign EMeRGe in Europe and Asia

Author

Förster, Eric, primary, Bönisch, Harald, additional, Neumaier, Marco, additional, Obersteiner, Florian, additional, Zahn, Andreas, additional, Hilboll, Andreas, additional, Kalisz Hedegaard, Anna Beata, additional, Daskalakis, Nikos, additional, Poulidis, Alexandros Panagiotis, additional, Vrekoussis, Mihalis, additional, Lichtenstern, Michael, additional, and Braesicke, Peter, additional

Published
2022
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45. Supplementary material to "Chemical and dynamical identification of emission outflows during the HALO campaign EMeRGe in Europe and Asia"

Author

Förster, Eric, primary, Bönisch, Harald, additional, Neumaier, Marco, additional, Obersteiner, Florian, additional, Zahn, Andreas, additional, Hilboll, Andreas, additional, Kalisz Hedegaard, Anna Beata, additional, Daskalakis, Nikos, additional, Poulidis, Alexandros Panagiotis, additional, Vrekoussis, Mihalis, additional, Lichtenstern, Michael, additional, and Braesicke, Peter, additional

Published
2022
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46. Supplementary material to "National CO2 budgets (2015–2020) inferred from atmospheric CO2 observations in support of the Global Stocktake"

Author

Byrne, Brendan, primary, Baker, David F., additional, Basu, Sourish, additional, Bertolacci, Michael, additional, Bowman, Kevin W., additional, Carroll, Dustin, additional, Chatterjee, Abhishek, additional, Chevallier, Frédéric, additional, Ciais, Philippe, additional, Cressie, Noel, additional, Crisp, David, additional, Crowell, Sean, additional, Deng, Feng, additional, Deng, Zhu, additional, Deutscher, Nicholas M., additional, Dubey, Manvendra, additional, Feng, Sha, additional, García, Omaira, additional, Griffith, David W. T., additional, Herkommer, Benedikt, additional, Hu, Lei, additional, Jacobson, Andrew R., additional, Janardanan, Rajesh, additional, Jeong, Sujong, additional, Johnson, Matthew S., additional, Jones, Dylan B. A., additional, Kivi, Rigel, additional, Liu, Junjie, additional, Liu, Zhiqiang, additional, Maksyutov, Shamil, additional, Miller, John B., additional, Miller, Scot M., additional, Morino, Isamu, additional, Notholt, Justus, additional, Oda, Tomohiro, additional, O’Dell, Christopher W., additional, Oh, Young-Suk, additional, Ohyama, Hirofumi, additional, Patra, Prabir K., additional, Peiro, Hélène, additional, Petri, Christof, additional, Philip, Sajeev, additional, Pollard, David F., additional, Poulter, Benjamin, additional, Remaud, Marine, additional, Schuh, Andrew, additional, Sha, Mahesh K., additional, Shiomi, Kei, additional, Strong, Kimberly, additional, Sweeney, Colm, additional, Té, Yao, additional, Tian, Hanqin, additional, Velazco, Voltaire A., additional, Vrekoussis, Mihalis, additional, Warneke, Thorsten, additional, Worden, John R., additional, Wunch, Debra, additional, Yao, Yuanzhi, additional, Yun, Jeongmin, additional, Zammit-Mangion, Andrew, additional, and Zeng, Ning, additional

Published
2022
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47. National CO2 budgets (2015–2020) inferred from atmospheric CO2 observations in support of the Global Stocktake

Author

Byrne, Brendan, primary, Baker, David F., additional, Basu, Sourish, additional, Bertolacci, Michael, additional, Bowman, Kevin W., additional, Carroll, Dustin, additional, Chatterjee, Abhishek, additional, Chevallier, Frédéric, additional, Ciais, Philippe, additional, Cressie, Noel, additional, Crisp, David, additional, Crowell, Sean, additional, Deng, Feng, additional, Deng, Zhu, additional, Deutscher, Nicholas M., additional, Dubey, Manvendra, additional, Feng, Sha, additional, García, Omaira, additional, Griffith, David W. T., additional, Herkommer, Benedikt, additional, Hu, Lei, additional, Jacobson, Andrew R., additional, Janardanan, Rajesh, additional, Jeong, Sujong, additional, Johnson, Matthew S., additional, Jones, Dylan B. A., additional, Kivi, Rigel, additional, Liu, Junjie, additional, Liu, Zhiqiang, additional, Maksyutov, Shamil, additional, Miller, John B., additional, Miller, Scot M., additional, Morino, Isamu, additional, Notholt, Justus, additional, Oda, Tomohiro, additional, O’Dell, Christopher W., additional, Oh, Young-Suk, additional, Ohyama, Hirofumi, additional, Patra, Prabir K., additional, Peiro, Hélène, additional, Petri, Christof, additional, Philip, Sajeev, additional, Pollard, David F., additional, Poulter, Benjamin, additional, Remaud, Marine, additional, Schuh, Andrew, additional, Sha, Mahesh K., additional, Shiomi, Kei, additional, Strong, Kimberly, additional, Sweeney, Colm, additional, Té, Yao, additional, Tian, Hanqin, additional, Velazco, Voltaire A., additional, Vrekoussis, Mihalis, additional, Warneke, Thorsten, additional, Worden, John R., additional, Wunch, Debra, additional, Yao, Yuanzhi, additional, Yun, Jeongmin, additional, Zammit-Mangion, Andrew, additional, and Zeng, Ning, additional

Published
2022
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48. Retrieval of greenhouse gases from GOSAT and GOSAT-2 using the FOCAL algorithm

Author

Noël, Stefan, primary, Reuter, Maximilian, additional, Buchwitz, Michael, additional, Borchardt, Jakob, additional, Hilker, Michael, additional, Schneising, Oliver, additional, Bovensmann, Heinrich, additional, Burrows, John P., additional, Di Noia, Antonio, additional, Parker, Robert J., additional, Suto, Hiroshi, additional, Yoshida, Yukio, additional, Buschmann, Matthias, additional, Deutscher, Nicholas M., additional, Feist, Dietrich G., additional, Griffith, David W. T., additional, Hase, Frank, additional, Kivi, Rigel, additional, Liu, Cheng, additional, Morino, Isamu, additional, Notholt, Justus, additional, Oh, Young-Suk, additional, Ohyama, Hirofumi, additional, Petri, Christof, additional, Pollard, David F., additional, Rettinger, Markus, additional, Roehl, Coleen, additional, Rousogenous, Constantina, additional, Sha, Mahesh Kumar, additional, Shiomi, Kei, additional, Strong, Kimberly, additional, Sussmann, Ralf, additional, Té, Yao, additional, Velazco, Voltaire A., additional, Vrekoussis, Mihalis, additional, and Warneke, Thorsten, additional

Published
2022
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49. Nitrous Oxide Profiling from Infrared Radiances (NOPIR): Algorithm description, application to 10 years of IASI observations and quality assessment

Author

Vandenbussche, Sophie, Langerock, Bavo, Vigouroux, Corinne, Buschmann, Matthias, Deutscher, Nicholas M., Feist, Dietrich G., García, Omaira E., Hannigan, James W., Hase, Frank, Kivi, Rigel, Kumps, Nicolas, Makarova, Maria V., Millet, Dylan B., Morino, Isamu, Nagahama, Tomoo, Notholt, Justus, Ohyama, Hirofumi, Ortega, Ivan, Petri, Christof, Rettinger, Markus, Schneider, Matthias, Servais, Christian P., Sha, Mahesh K., Shiomi, Kei, Smale, Dan, Strong, Kimberly, Sussmann, Ralf, Té, Yao, Velazco, Voltaire A., Vrekoussis, Mihalis, Warneke, Thorsten, Wells, Kelley C., Wunch, Debra, Zhou, Minqiang, and De Mazière, Martine

Subjects
Nitrous oxide, IASI, Retrieval, TCCON, Greenhouse gas, nitrous oxide, greenhouse gas, retrieval, validation, Earth sciences, Satellite, Validation, ddc:550, remote sensing N2O, General Earth and Planetary Sciences, NDACC, long-term record
Abstract

Nitrous oxide (N$_{2}$O) is the third most abundant anthropogenous greenhouse gas (after carbon dioxide and methane), with a long atmospheric lifetime and a continuously increasing concentration due to human activities, making it an important gas to monitor. In this work, we present a new method to retrieve N$_{2}$O concentration profiles (with up to two degrees of freedom) from each cloud-free satellite observation by the Infrared Atmospheric Sounding Interferometer (IASI), using spectral micro-windows in the N$_{2}$O ν$_{3}$ band, the Radiative Transfer for TOVS (RTTOV) tools and the Tikhonov regularization scheme. A time series of ten years (2011–2020) of IASI N$_{2}$O profiles and integrated partial columns has been produced and validated with collocated ground-based Network for the Detection of Atmospheric Composition Change (NDACC) and Total Carbon Column Observing Network (TCCON) data. The importance of consistency in the ancillary data used for the retrieval for generating consistent time series has been demonstrated. The Nitrous Oxide Profiling from Infrared Radiances (NOPIR) N$_{2}$O partial columns are of very good quality, with a positive bias of 1.8 to 4% with respect to the ground-based data, which is less than the sum of uncertainties of the compared values. At high latitudes, the comparisons are a bit worse, due to either a known bias in the ground-based data, or to a higher uncertainty in both ground-based and satellite retrievals.

Published
2022

50. Data and scripts for manuscript 'Efficacy of high-resolution satellite observations in inverse modeling of carbon monoxide emissions'

Author

Nüß, Johann Rasmus, Daskalakis, Nikos, Piwowarczyk, Fabian Günther, Gkouvousis, Angelos, Schneising, Oliver, Buchwitz, Michael, Kanakidou, Maria, Krol, Maarten C., Vrekoussis, Mihalis, Nüß, Johann Rasmus, Daskalakis, Nikos, Piwowarczyk, Fabian Günther, Gkouvousis, Angelos, Schneising, Oliver, Buchwitz, Michael, Kanakidou, Maria, Krol, Maarten C., and Vrekoussis, Mihalis

Abstract

Collection of analysis and plotting scripts and model in- and output needed to reproduce the simulations, figures and analysis for the manuscript "Efficacy of high-resolution satellite observations in inverse modeling of carbon monoxide emissions" authored by Nüß et al. See the included README for more information on what each file includes.

Published
2022

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