12 results on '"Ed Dlugokencky"'
Search Results
2. Methane budget estimates in Finland from the CarbonTracker Europe-CH4 data assimilation system
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Aki Tsuruta, Tuula Aalto, Leif Backman, Maarten C. Krol, Wouter Peters, Sebastian Lienert, Fortunat Joos, Paul A. Miller, Wenxin Zhang, Tuomas Laurila, Juha Hatakka, Ari Leskinen, Kari E. J. Lehtinen, Olli Peltola, Timo Vesala, Janne Levula, Ed Dlugokencky, Martin Heimann, Elena Kozlova, Mika Aurela, Annalea Lohila, Mari Kauhaniemi, and Angel J. Gomez-Pelaez
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ch4 flux ,atmospheric ch4 ,finland ,data assimilation ,flux estimation ,Meteorology. Climatology ,QC851-999 - Abstract
We estimated the CH4 budget in Finland for 2004–2014 using the CTE-CH4 data assimilation system with an extended atmospheric CH4 observation network of seven sites from Finland to surrounding regions (Hyytiälä, Kjølnes, Kumpula, Pallas, Puijo, Sodankylä, and Utö). The estimated average annual total emission for Finland is 0.6 ± 0.5 Tg CH4 yr−1. Sensitivity experiments show that the posterior biospheric emission estimates for Finland are between 0.3 and 0.9 Tg CH4 yr−1, which lies between the LPX-Bern-DYPTOP (0.2 Tg CH4 yr−1) and LPJG-WHyMe (2.2 Tg CH4 yr−1) process-based model estimates. For anthropogenic emissions, we found that the EDGAR v4.2 FT2010 inventory (0.4 Tg CH4 yr−1) is likely to overestimate emissions in southernmost Finland, but the extent of overestimation and possible relocation of emissions are difficult to derive from the current observation network. The posterior emission estimates were especially reliant on prior information in central Finland. However, based on analysis of posterior atmospheric CH4, we found that the anthropogenic emission distribution based on a national inventory is more reliable than the one based on EDGAR v4.2 FT2010. The contribution of total emissions in Finland to global total emissions is only about 0.13%, and the derived total emissions in Finland showed no trend during 2004–2014. The model using optimized emissions was able to reproduce observed atmospheric CH4 at the sites in Finland and surrounding regions fairly well (correlation , bias ppb), supporting adequacy of the observations to be used in atmospheric inversion studies. In addition to global budget estimates, we found that CTE-CH4 is also applicable for regional budget estimates, where small scale (11 in this case) optimization is possible with a dense observation network.
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- 2019
- Full Text
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3. Declining, seasonal-varying emissions of sulfur hexafluoride from the United States
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Phil DeCola, Lei Hu, Deborah Ottinger, Stephanie Bogle, Stephen Montzka, Ed Dlugokencky, Arlyn Andrews, Kirk Thoning, Colm Sweeney, Geoff Geoff, Lauren Aepli, and Andrew Crotwell
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Atmospheric Science - Abstract
Sulfur hexafluoride (SF6) is the most potent greenhouse gas (GHG), and its atmospheric abundance, albeit small, has been increasing rapidly. Although SF6 is used to assess atmospheric transport modeling and its emissions influence the climate for millennia, SF6 emission magnitudes and distributions have substantial uncertainties. In this study, we used NOAA's ground-based and airborne measurements of SF6 to estimate SF6 emissions from the United States between 2007 and 2018. Our results suggest a substantial decline of US SF6 emissions, a trend also reported in the US Environmental Protection Agency's (EPA) national inventory submitted under the United Nations Framework Convention on Climate Change (UNFCCC), implying that US mitigation efforts have had some success. However, the magnitudes of annual emissions derived from atmospheric observations are 40 %–250 % higher than the EPA's national inventory and substantially lower than the Emissions Database for Global Atmospheric Research (EDGAR) inventory. The regional discrepancies between the atmosphere-based estimate and EPA's inventory suggest that emissions from electric power transmission and distribution (ETD) facilities and an SF6 production plant that did not or does not report to the EPA may be underestimated in the national inventory. Furthermore, the atmosphere-based estimates show higher emissions of SF6 in winter than in summer. These enhanced wintertime emissions may result from increased maintenance of ETD equipment in southern states and increased leakage through aging brittle seals in ETD in northern states during winter. The results of this study demonstrate the success of past US SF6 emission mitigations and suggest that substantial additional emission reductions might be achieved through efforts to minimize emissions during servicing or through improving sealing materials in ETD.
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- 2023
4. Declining, seasonal-varying emissions of sulfur hexafluoride from the United States point to a new mitigation opportunity
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Lei Hu, Deborah Ottinger, Stephanie Bogle, Stephen Montzka, Phil DeCola, Ed Dlugokencky, Arlyn Andrews, Kirk Thoning, Colm Sweeney, Geoff Dutton, Lauren Aepli, and Andrew Crotwell
- Abstract
Sulfur hexafluoride (SF6) is the most potent greenhouse gas (GHG), and its atmospheric abundance, albeit small, has been increasing rapidly. Although SF6 is used to assess atmospheric transport modeling and its emissions influence the climate for millennia, SF6 emission magnitudes and distributions have substantial uncertainties. In this study, we used NOAA's ground-based and airborne measurements of SF6 to estimate SF6 emissions from the United States between 2007 and 2018. Our results suggest a substantial decline of US SF6 emissions, a trend also reported in the US Environmental Protection Agency's (EPA) national inventory submitted under the United Nations Framework Convention on Climate Change (UNFCCC), implying that US mitigation efforts have had some success. However, the magnitudes of annual emissions derived from atmospheric observations are 40 %–250 % higher than the EPA's national inventory and substantially lower than the Emissions Database for Global Atmospheric Research (EDGAR) inventory. The regional discrepancies between the atmosphere-based estimate and EPA's inventory suggest that emissions from electric power transmission and distribution (ETD) facilities and an SF6 production plant that did not or does not report to the EPA may be underestimated in the national inventory. Furthermore, the atmosphere-based estimates show higher emissions of SF6 in winter than in summer. These enhanced wintertime emissions may result from increased maintenance of ETD equipment in southern states and increased leakage through aging brittle seals in ETD in northern states during winter. The results of this study demonstrate the success of past US SF6 emission mitigations and suggest that substantial additional emission reductions might be achieved through efforts to minimize emissions during servicing or through improving sealing materials in ETD.
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- 2023
5. Inverse modeling of pan-Arctic methane emissions at high spatial resolution: what can we learn from assimilating satellite retrievals and using different process-based wetland and lake biogeochemical models?
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Zeli Tan, Qianlai Zhuang, Daven K. Henze, Christian Frankenberg, Ed Dlugokencky, Colm Sweeney, Alexander J. Turner, Motoki Sasakawa, and Toshinobu Machida
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- 2016
- Full Text
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6. Supplementary material to 'Investigation of the global methane budget over 1980–2017 using GFDL-AM4.1'
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Jian He, Vaishali Naik, Larry W. Horowitz, Ed Dlugokencky, and Kirk Thoning
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- 2019
7. Investigation of the global methane budget over 1980–2017 using GFDL-AM4.1
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Jian He, Vaishali Naik, Larry W. Horowitz, Ed Dlugokencky, and Kirk Thoning
- Abstract
Changes in atmospheric methane abundance have implications for both chemistry and climate as methane is both a strong greenhouse gas and an important precursor for tropospheric ozone. A better understanding of the drivers of trends and variability in methane abundance over the recent past is therefore critical for building confidence in projections of future methane levels. In this work, the representation of methane in the atmospheric chemistry model AM4.1 is improved by optimizing total methane emissions (to an annual mean of 576 ± 32 Tg yr−1) to match surface observations over 1980–2017. The simulations with optimized global emissions are in general able to capture the observed global trend, variability, seasonal cycle, and latitudinal gradient of methane. Simulations with different emission adjustments suggest that increases in methane sources (mainly from energy and waste sectors) balanced by increases in methane sinks (mainly due to increases in OH levels) lead to methane stabilization (with an imbalance of 5 Tg yr−1) during 1999–2006, and that increases in methane sources combined with little change in sinks (despite small decreases in OH levels) during 2007–2012 lead to renewed methane growth (with an imbalance of 14 Tg yr−1 for 2007–2017). Compared to 1999–2006, both methane emissions and sinks are greater (by 31 Tg yr−1 and 22 Tg yr−1, respectively) during 2007–2017. Our results also indicate that the energy sector is more likely a major contributor to the methane renewed growth after 2006 than wetland, as increases in wetland emissions alone are not able to explain the renewed methane growth with constant anthropogenic emissions. In addition, a significant increase in wetland emissions would be required starting in 2006, if anthropogenic emissions declined, for wetland emissions to drive renewed growth in methane, which is a less likely scenario. Simulations with varying OH levels indicate that 1 % change in OH levels could lead to an annual mean of ~ 4 Tg yr−1 difference in the optimized emissions and 0.08 year difference in the estimated tropospheric methane lifetime. Continued increases in methane emissions along with decreases in tropospheric OH concentrations during 2008–2015 prolong methane lifetime and therefore amplify the response of methane concentrations to emission changes. Uncertainties still exist in the partitioning of emissions among individual sources and regions.
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- 2019
8. Inverse modelling of European CH4 emissions during 2006–2012 using different inverse models and reassessed atmospheric observations
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Peter Bergamaschi, Ute Karstens, Alistair J. Manning, Marielle Saunois, Aki Tsuruta, Antoine Berchet, Alexander T. Vermeulen, Tim Arnold, Greet Janssens-Maenhout, Samuel Hammer, Ingeborg Levin, Martina Schmidt , Michel Ramonet, Morgan Lopez, Jost Lavric, Tuula Aalto, Huilin Chen, Dietrich G. Feist, Christoph Gerbig, László Haszpra, Ove Hermansen, Giovanni Manca, John Moncrieff, Frank Meinhardt, Jaroslaw Necki, Michal Galkowski, Simon O'Doherty, Nina Paramonova, Hubertus A. Scheeren, Martin Steinbacher, and Ed Dlugokencky
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010504 meteorology & atmospheric sciences ,13. Climate action ,010501 environmental sciences ,7. Clean energy ,01 natural sciences ,0105 earth and related environmental sciences - Abstract
We present inverse modelling (top-down) estimates of European methane (CH4) emissions for 2006–2012 based on a new quality-controlled and harmonized in-situ data set from 18 European atmospheric monitoring stations. We applied an ensemble of seven inverse models and performed four inversion experiments, investigating the impact of different sets of stations and the use of a priori information on emissions. The inverse models infer total CH4 emissions of 26.7 (20.2–29.7) Tg CH4 yr−1 (mean, 10th and 90th percentiles from all inversions) for the EU-28 for 2006–2012 from the four inversion experiments. For comparison, total anthropogenic CH4 emissions reported to UNFCCC (bottom-up, based on statistical data and emissions factors) amount to only 21.3 Tg CH4 yr−1 (2006) to 18.8 Tg CH4 yr−1 (2012). A potential explanation for the higher range of top-down estimates compared to bottom-up inventories could be the contribution from natural sources, such as peatlands, wetlands, and wet soils. Based on seven different wetland inventories from the Wetland and Wetland CH4 Inter-comparison of Models Project (WETCHIMP) total wetland emissions of 4.3 (2.3–8.2) CH4 yr−1 from EU-28 are estimated. The hypothesis of significant natural emissions is supported by the finding that several inverse models yield significant seasonal cycles of derived CH4 emissions with maxima in summer, while anthropogenic CH4 emissions are assumed to have much lower seasonal variability. Furthermore, we investigate potential biases in the inverse models by comparison with regular aircraft profiles at four European sites and with vertical profiles obtained during the Infrastructure for Measurement of the European Carbon Cycle (IMECC) aircraft campaign. We present a novel approach to estimate the biases in the derived emissions, based on the comparison of simulated and measured enhancements of CH4 compared to the background, integrated over the entire boundary layer and over the lower troposphere. This analysis identifies regional biases for several models at the aircraft profile sites in France, Hungary and Poland.
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- 2017
9. Supplementary material to 'Inverse modelling of European CH4 emissions during 2006–2012 using different inverse models and reassessed atmospheric observations'
- Author
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Peter Bergamaschi, Ute Karstens, Alistair J. Manning, Marielle Saunois, Aki Tsuruta, Antoine Berchet, Alexander T. Vermeulen, Tim Arnold, Greet Janssens-Maenhout, Samuel Hammer, Ingeborg Levin, Martina Schmidt , Michel Ramonet, Morgan Lopez, Jost Lavric, Tuula Aalto, Huilin Chen, Dietrich G. Feist, Christoph Gerbig, László Haszpra, Ove Hermansen, Giovanni Manca, John Moncrieff, Frank Meinhardt, Jaroslaw Necki, Michal Galkowski, Simon O'Doherty, Nina Paramonova, Hubertus A. Scheeren, Martin Steinbacher, and Ed Dlugokencky
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- 2017
10. Supplementary material to 'Development of CarbonTracker Europe-CH4 – Part 2: global methane emission estimates and their evaluation for 2000–2012'
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Aki Tsuruta, Tuula Aalto, Leif Backman, Janne Hakkarainen, Ingrid T. van der Laan-Luijkx, Maarten C. krol, Renato Spahni, Sander Houweling, Marko Laine, Ed Dlugokencky, Angel J. Gomez-Pelaez, Marcel van der Schoot, Ray Langenfelds, Raymond Ellul, Jgor Arduini, Francesco Apadula, Christoph Gerbig, Dietrich G. Feist, Rigel Kivi, Yukio Yoshida, and Wouter Peters
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- 2016
11. Methane budget estimates in Finland from the CarbonTracker Europe-CH 4 data assimilation system
- Author
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Aki Tsuruta, Tuula Aalto, Leif Backman, Maarten C. Krol, Wouter Peters, Sebastian Lienert, Fortunat Joos, Paul A. Miller, Wenxin Zhang, Tuomas Laurila, Juha Hatakka, Ari Leskinen, Kari E. J. Lehtinen, Olli Peltola, Timo Vesala, Janne Levula, Ed Dlugokencky, Martin Heimann, Elena Kozlova, Mika Aurela, Annalea Lohila, Mari Kauhaniemi, and Angel J. Gomez-Pelaez
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- View/download PDF
12. Unusual characteristics of the carbon cycle during the 2015−2016 El Niño
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Ana Bastos, Kai Wang, Stephen W. Pacala, Hao Xu, Shilong Piao, Philippe Ciais, Jiafu Mao, Ralph F. Keeling, Xiaoying Shi, Frédéric Chevallier, Anping Chen, Chris Huntingford, Xuhui Wang, Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University [Beijing], 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), Environmental Sciences Division [Oak Ridge], Oak Ridge National Laboratory [Oak Ridge] (ORNL), UT-Battelle, LLC-UT-Battelle, LLC, Centre for Ecology and Hydrology [Wallingford] (CEH), Natural Environment Research Council (NERC), Department of Biogeochemical Integration [Jena], Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Scripps Institution of Oceanography (SIO - UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), Department of Ecology and Evolutionary Biology [Princeton], Princeton University, Colorado State University [Fort Collins] (CSU), U.S. Department of Energy, USDOE: DE‐AC05‐00OR22725, Office of Science, SC, Biological and Environmental Research, BER, National Natural Science Foundation of China, NSFC: 41861134036, 41988101, We thank Dr. Pieter Tans and Dr. Ed Dlugokencky for providing the CO mole fraction data. We also thank the TRENDYv6 modelers for their simulations and Dr. Christian Rödenbeck for the Jena CarboScope inversion datasets. This study was supported by the National Natural Science Foundation of China (grant nos. 41861134036 and 41988101) and an Oak Ridge National Lab subcontract (grant no. 4000167205). J. Mao and X. Shi were supported by the Reducing Uncertainties in Biogeochemical Interactions through Synthesis and Computation Science Focus Area and the Terrestrial Ecosystem Science Scientific Focus Area project in the Earth and Environmental Systems Sciences Division of the Biological and Environmental Research (BER) office in the US Department of Energy Office of Science. Oak Ridge National Laboratory is supported by the Office of Science of the US Department of Energy under contract no. DE‐AC05‐00OR22725. 2, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Scripps Institution of Oceanography (SIO), and University of California-University of California
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,[SDE.MCG]Environmental Sciences/Global Changes ,chemistry.chemical_element ,Atmospheric sciences ,010603 evolutionary biology ,01 natural sciences ,Ecology and Environment ,Carbon Cycle ,Carbon cycle ,atmospheric CO2 growth rate (CGR) ,Meteorology and Climatology ,medicine ,Environmental Chemistry ,Ecosystem ,El Niño ,0105 earth and related environmental sciences ,General Environmental Science ,El Nino-Southern Oscillation ,Global and Planetary Change ,Ecology ,Atmosphere ,Anomaly (natural sciences) ,Northern Hemisphere ,Carbon Dioxide ,15. Life on land ,Seasonality ,medicine.disease ,Carbon ,northern terrestrial ecosystems ,Productivity (ecology) ,chemistry ,13. Climate action ,CO2 seasonal-cycle amplitude (SCA) ,soil water deficit ,Environmental science ,Terrestrial ecosystem ,net biome productivity (NBP) - Abstract
International audience; The 2015−2016 El Niño was one of the strongest on record, but its influence on the carbon balance is less clear. Using Northern Hemisphere atmospheric CO2 observations, we found both detrended atmospheric CO2 growth rate (CGR) and CO2 seasonal-cycle amplitude (SCA) of 2015−2016 were much higher than that of other El Niño events. The simultaneous high CGR and SCA were unusual, because our analysis of long-term CO2 observations at Mauna Loa revealed a significantly negative correlation between CGR and SCA. Atmospheric inversions and terrestrial ecosystem models indicate strong northern land carbon uptake during spring but substantially reduced carbon uptake (or high emissions) during early autumn, which amplified SCA but also resulted in a small anomaly in annual carbon uptake of northern ecosystems in 2015−2016. This negative ecosystem carbon uptake anomaly in early autumn was primarily due to soil water deficits and more litter decomposition caused by enhanced spring productivity. Our study demonstrates a decoupling between seasonality and annual carbon cycle balance in northern ecosystems over 2015−2016, which is unprecedented in the past five decades of El Niño events.
- Published
- 2021
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