【As of Nov 20, 2025】

SASAKAWA Motoki

Researcher Name: SASAKAWA Motoki

Div (Section) name/title: Earth System Division（Office for Atmospheric and Oceanic Monitoring）／Chief Senior Researcher

Research Subject: Observation and data analysis of greenhouse gases (CO2 and CH4) over Siberia.

Degree(s): Doctor of Science

Professional Qualification(s): Science,Chemistry

Environmental Speciality Field: global warming,carbon cycle

Membership of Academic Society: The Geochemical Society of Japan,AGU,Meteorological Society of Japan

Research Subject

Fiscal Year: 2025
- 27188 : Climate Change and Air Quality Research Program
- 27203 : Quantitative evaluation of natural and anthropogenic sinks and sources of greenhouse gases at global scale
- 27204 : Quantitative evaluation of anthropogenic sources of SLCFs and greenhouse gases at region, country and city　scale
- 27244 : Earth System Domain: Foresight and Advanced Basic Research
- 27396 : Long-term analysis of greenhouse gases in the polar region with the Siberian tower network
- 27413 : Atmospheric and Oceanic Monitoring
- 27509 : Fundamental studies for contributing atmospheric and oceanic monitoring
Fiscal Year: 2024
- 26799 : Climate Change and Air Quality Research Program
- 26815 : Quantitative evaluation of natural and anthropogenic sinks and sources of greenhouse gases at global scale
- 26816 : Quantitative evaluation of anthropogenic sources of SLCFs and greenhouse gases at region, country and city　scale
- 26859 : Earth System Domain: Foresight and Advanced Basic Research
- 27102 : Atmospheric and Oceanic Monitoring
- 27164 : Fundamental studies for contributing atmospheric and oceanic monitoring
Fiscal Year: 2023
- 26400 : Climate Change and Air Quality Research Program
- 26409 : Quantitative evaluation of natural and anthropogenic sinks and sources of greenhouse gases at global scale
- 26410 : Quantitative evaluation of anthropogenic sources of SLCFs and greenhouse gases at region, country and city　scale
- 26450 : Earth System Domain: Foresight and Advanced Basic Research
- 26615 : Long-term analysis of greenhouse gases in the polar region with the Siberian tower network
- 26654 : Atmospheric and Oceanic Monitoring
- 26656 : Fundamental studies for contributing atmospheric and oceanic monitoring
Fiscal Year: 2022
- 25964 : Climate Change and Air Quality Research Program
- 25965 : Quantitative evaluation of natural and anthropogenic sinks and sources of greenhouse gases at global scale
- 25966 : Quantitative evaluation of anthropogenic sources of SLCFs and greenhouse gases at region, country and city　scale
- 26006 : Earth System Domain: Foresight and Advanced Basic Research
- 26264 : Atmospheric and Oceanic Monitoring
- 26267 : Fundamental studies for contributing atmospheric and oceanic monitoring
- 26270 : Long-term analysis of greenhouse gases in the polar region with the Siberian tower network
Fiscal Year: 2021
- 25498 : Climate Change and Air Quality Research Program
- 25506 : Quantitative evaluation of natural and anthropogenic sinks and sources of greenhouse gases at global scale
- 25507 : Quantitative evaluation of anthropogenic sources of SLCFs and greenhouse gases at region, country and city　scale
- 25655 : Earth System Domain: Foresight and Advanced Basic Research
- 25745 : Fundamental studies for contributing atmospheric and oceanic monitoring
- 25833 : Atmospheric and Oceanic Monitoring
- 25900 : Analysis of long-term variation in green house gases using a tower network in West Siberia
Fiscal Year: 2020
- 25113 : Long-term Monitoring and Database for Global Environmental Research and Supporting for Related Activities
- 25128 : Study on Multi-scale Evaluation System for GHG Variation and Mitigation
- 25396 : Analysis of long-term variation in green house gases using a tower network in West Siberia
- 25411 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2019
- 24708 : Study on Multi-scale Evaluation System for GHG Variation and Mitigation
- 24745 : Long-term Monitoring and Database for Global Environmental Research and Supporting for Related Activities
- 25002 : Analysis of long-term variation in green house gases using a tower network in West Siberia
- 25019 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2018
- 24291 : Study on multi-scale evaluation system for GHG variation and mitigation
- 24315 : Long-term monitoring and database for global environmental research and supporting for related activities
- 24571 : Analysis of long-term variation in green house gases using a tower network in West Siberia
- 24578 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2017
- 23837 : Study on multi-scale evaluation system for GHG variation and mitigation
- 23877 : Long-term monitoring and database for global environmental research and supporting for related activities
- 24143 : Analysis of long-term variation in green house gases using a tower network in West Siberia
- 24146 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2016
- 23399 : Study on multi-scale evaluation system for GHG variation and mitigation
- 23470 : Long-term monitoring and database for global environmental research and supporting for related activities
- 23733 : Analysis for long-term variation in greenhouse gases (CO2 and CH4) using a tower network over Siberia
- 23735 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2015
- 22992 : Study on characteristics of GHG in the atmosphere and outlook of their future concentration
- 23026 : Long-term monitoring and database for global environmental research and supporting for related activities
- 23186 : Analysis for long-term variation in greenhouse gases (CO2 and CH4) using a tower network over Siberia
- 23190 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2014
- 22580 : Study on characteristics of GHG in the atmosphere and outlook of their future concentration
- 22614 : Long-term monitoring and database for global environmental research and supporting for related activities
- 22645 : Analysis for long-term variation in greenhouse gases (CO2 and CH4) using a tower network over Siberia
- 22673 : Characterization and quantification of global methane emissions by utilizing GOSAT and in-situ measurements
- 22920 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2013
- 22164 : Study on characteristics of GHG in the atmosphere and outlook of their future concentration
- 22198 : Long-term monitoring and database for global environmental research and supporting for related activities
- 22217 : Characterization and quantification of global methane emissions by utilizing GOSAT and in-situ measurements
- 22378 : Analysis for long-term variation in greenhouse gases (CO2 and CH4) using a tower network over Siberia
- 22379 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2012
- 21735 : Study on characteristics of GHG in the atmosphere and outlook of their future concentration
- 21769 : Long-term Monitoring and database for Global Environmental Research and supporting for related activities
- 22042 : Characterization and quantification of global methane emissions by utilizing GOSAT and in-situ measurements
- 22115 : Analysis for long-term variation in greenhouse gases (CO2 and CH4) using a tower network over Siberia
- 22118 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2011
- 21284 : Study on characteristics of GHG in the atmosphere and outlook of their future concentration
- 21327 : Long-term Monitoring and database for Global Environmental Research and supporting for related activities
- 21592 : Estimation of CO2 and CH4 fluxes in Siberia using a tower observation network.
- 21595 : Atmospheric and Oceanic Monitoring
Fiscal Year: 2010
- 21092 : Study on long-term variation mechanisms of greenhouse gas concentrations and their regional characteristics
- 21229 : Estimation of CO2 and CH4 fluxes in Siberia using a tower observation network.
Fiscal Year: 2009
- 20608 : Study on long-term variation mechanisms of greenhouse gas concentrations and their regional characteristics

View all

Research Result (Publication)

all
Original Paper
Other Publications

Original Paper
Melt period methane emissions in northern high latitude wetlands are governed by the length of the period and presence of permafrost

Presenter : Hyvarinen S., Tenkanen M.K., Tsuruta A., Erkkila A., Rautiainen K., Aaltonen H., Sasakawa M., Aalto T.
Title : , Atmospheric Chemistry and Physics, 26(10):7555-7587 (2026)
Original Paper
Global Methane Budget 2000-2020

Presenter : Saunois M., Martinez A., Poulter B., Zhang Z., Raymond P. A., Regnier P., Canadell J.G., Jackson R.B., Patra P.K., Bousquet P., Ciais P., Dlugokencky E.J., Lan X., Allen G.H., Bastviken D., Beerling D.J., Belikov D.A., Blake D.R., Castaldi S., Crippa M., Deemer B.R., Dennison F., Etiope G., Gedney N., Hoglund-Isaksson L., Holgerson M.A., Hopcroft P.O., Hugelius G., Ito A., Jain A.K., Janardanan Achari R., Johnson M.S., Kleinen T., Krummel P.B., Lauerwald R., Li T., Liu X., McDonald K.C., Melton J.R., Muhle J., Muller J., Murguia-Flores F., Niwa Y., Noce S., Pan S., Parker R.J., Peng C., Ramonet M., Riley W. J., Rocher-Ros G., Rosentreter J.A., Sasakawa M., Segers A., Smith S.J., Stanley E.H., Thanwerdas J., Tian H., Tsuruta A., Tubiello F.N., Weber T.S., van der Werf G.R., Worthy D.E.J., Xi Y., Yoshida Y., Zhang W., Zheng B., Zhu Q., Zhu Q., Zhuang Q.
Title : , Earth System Science Data, 17(5):1873-1958 (2025)
Original Paper
Long-term and interannual variations of atmospheric methane observed by the NIES and collaborative observation networks

Presenter : Umezawa T., Tohjima Y., Terao Y., Sasakawa M., Mueller A., Saeki T., Machida T., Nakaoka S., Nara H., Nomura S., Nishihashi M., Mukai H., Frey M., Morino I., Ohyama H., Yoshida Y., Zeng J., Noda H., Saito M., Matsunaga T., Sugita T., Tanimoto H., Niwa Y., Ito A., Yamashita Y., Shirai T., Ishizawa M., Ishijima K., Tsuboi K., Sawa Y., Matsueda H.
Title : , Progress in Earth and Planetary Science, 12(39): (2025)
Original Paper
Revised methodology for CO2 and CH4 measurements at remote sites using a working standard-gas-saving system

Presenter : Sasakawa M., Tsuda N., Machida T., Arshinov M., Davydov D., Fofonov A., Belan B.
Title : , Atmospheric Measurement Techniques, 18(8):1717-1730 (2025)
Original Paper
Multi-observational estimation of regional and sectoral emission contributions to the persistent high growth rate of atmospheric CH4 for 2020-2022

Presenter : Niwa Y., Tohjima Y., Terao Y., Saeki T., Ito A., Umezawa T., Yamada K., Sasakawa M., Machida T., Nakaoka S., Nara H., Tanimoto H., Mukai H., Yoshida Y., Morimoto S., Takatsuji S., Tsuboi K., Sawa Y., Matsueda H., Ishijima K., Fujita R., Goto D., Lan X., Schuldt K., Heliasz M., Biermann T., Chmura L., Necki J., Xueref-Remy I., Sferlazzo
Title : , Atmospheric Chemistry and Physics, 25:6757-6785 (2025)
Original Paper
Efficient use of a Lagrangian particle dispersion model for atmospheric inversions using satellite observations of column mixing ratios

Presenter : Schneider P., Thompson R.L., Krishnankutty N., Pisso I., Schneider P., Stebel K., Sasakawa M., Stohl A., Platt S.M.
Title : , Atmospheric Chemistry and Physics, 25(19):12737-12751 (2025)
Original Paper
Observed APO Seasonal Cycle in the Pacific: Estimation of Autumn O2 Oceanic Emissions

Presenter : Tohjima Y., Shirai T., Ishizawa M., Mukai H., Machida T., Sasakawa M., Terao Y., Tsuboi K., Takao S., Nakaoka S.
Title : , Global Biogeochemical Cycles, 38: (2024)
Original Paper
Near-real-time estimation of fossil fuel CO2 emissions from China based on atmospheric observations on Hateruma and Yonaguni Islands, Japan

Presenter : Tohjima Y., Niwa Y., Patra P.K., Mukai H., Machida T., Sasakawa M., Tsuboi K., Saito K., Ito A.
Title : , Progress in Earth and Planetary Science (2023)
Original Paper
Autumn cooling paused increased CO2 release in central Eurasia

Presenter : Kondo M., Sasakawa M., Machida T., Arshinov M., Hiyama T.
Title : , Nature Climate Change, 13:334-337 (2023)
Original Paper
Estimating methane emissions in the Arctic nations using surface observations from 2008 to 2019

Presenter : Wittig S., Berchet A., Pison I., Saunois M., Thanwerdas J., Martinez A., Paris J.D., Machida T., Sasakawa M., Worthy D.E.J., Lan X., Thompson R.L., Sollum E., Arshinov M.
Title : , Atmospheric Chemistry and Physics, 23(11):6457-6485 (2023)
Original Paper
Forward and Inverse Modelling of Atmospheric Nitrous Oxide Using MIROC4-Atmospheric Chemistry-Transport Model

Presenter : Patra P. K., Dlugokencky E. J., Elkins J. W., Dutton G. S., Tohjima Y., Sasakawa M., Ito A., Weiss R. F., Manizza M., Prinn R. G., Bianchi D., Nevison C., Solazzo E., Lee H., Joo S., Kort E. A., Maity S., Takigawa M.
Title : , Journal of the Meteorological Society of Japan. Ser. II, 100(2):361-386 (2022)
Original Paper
Estimating emissions of methane consistent with atmospheric measurements of methane and δ13C of methane

Presenter : Basu S., Lan X., Dlugokencky E., Michel S., Schwietzke S., Miller J.B., Bruhwiler L., Oh Y., Tans P.P., Apadula F., Gatti L.V., Jordan A., Neck J., Sasakawa M., Morimoto S., Iorio T.D., Lee H., Arduini J., Manca G.
Title : , Atmospheric Chemistry and Physics, 22:15351-15377 (2022)
Original Paper
Measurement report: Regional characteristics of seasonal and long-term variations in greenhouse gases at Nainital, India, and Comilla, Bangladesh

Presenter : Nomura S., Naja M., Ahmed M.K., Mukai H., Terao Y., Machida T., Sasakawa M., Patra P. K.
Title : , Atmospheric Chemistry and Physics, 21:16427-16452 (2021)
Original Paper
Siberian and temperate ecosystems shape Northern Hemisphere atmospheric CO2 seasonal amplification

Presenter : Lin X., Rogers B.M., Sweeney C., Chevallier F., Arshinov M., Dlugokencky E., Machida T., Sasakawa M., Tans P., Keppel-Aleks G.
Title : , Proceedings of the National Academy of Sciences of the United States of America, 1-9 (2020)
Original Paper
Detection of fossil-fuel CO2 plummet in China due to COVID-19 by observation at Hateruma

Presenter : Tohjima Y., Patra P. K., Niwa Y., Mukai H., Sasakawa M., Machida T.
Title : , Scientific Reports (2020)
Original Paper
Analysis of the diurnal, weekly, and seasonal cycles and annual trends in atmospheric CO2 and CH4 at tower network in Siberia from 2005 to 2016

Presenter : Belikov D., Arshinov M., Belan B., Davydov D., Fofonov A., Sasakawa M., Machida T.
Title : , Atmosphere, 10(11): (2019)
Original Paper
Methane Emission Estimates by the Global High-Resolution Inverse Model Using National Inventories

Presenter : Wang F., Maksyutov S., Tsuruta A., Janardanan achari R., Ito A., Sasakawa M., Machida T., Morino I., Yoshida Y., Kaiser J.W., Janssens-Maenhout G., Dlugokencky E.J., Mammarella I., Lavric J.V., Matsunaga T.
Title : , Remote Sensing, 11（21）(2489): (2019)
Original Paper
Country-Scale Analysis of Methane Emissions with a High-Resolution Inverse Model Using GOSAT and Surface Observations

Presenter : Janardanan achari R., Maksyutov S., Tsuruta A., Wang F., Tiwari Y.K., Valsala V., Ito A., Yoshida Y., Kaiser J.W., Janssens-Maenhout G., Arshinov M., Sasakawa M., Tohjima Y., Worthy D.E.J., Dlugokencky E.J., Ramonet M., Arduini J., Lavric J.V., Piacentino S., Krummel P.B., Langenfelds R.L., Mammarella I., Matsunaga T.
Title : , Remote Sensing, 12(3）(375): (2019)
Original Paper
A global synthesis inversion analysis of recent variability in CO2 fluxes using GOSAT and in situ observations

Presenter : Wang J.S., Kawa S.R., Collatz G.J., Sasakawa M., Gatti L.V., Machida T., Liu Y., Manyin M.E.
Title : , Atmospheric Chemistry and Physics, 18(15): (2018)
Original Paper
Three-dimensional methane distribution simulated with FLEXPART 8-CTM-1.1 constrained with observation data

Presenter : Groot Zwaaftink C.D., Henne S., Thompson R.L., Dlugokencky E.J., Machida T., Paris J.D., Sasakawa M., Segers A., Sweeney C., Stohl A.
Title : , Geoscientific Model Development, 11(11):4469-4487 (2018)
Original Paper
Impact of Siberian observations on the optimization of surface CO2 flux

Presenter : Kim J., Kim H.M., Cho C.H., Boo K.O., Jacobson A.R., Sasakawa M., Machida T., Arshinov M., Fedoseev N.
Title : , Atmospheric Chemistry and Physics, 17(4):2881-2899 (2017)
Original Paper
A 4D-Var inversion system based on the icosahedral grid model (NICAM-TM 4D-Var v1.0)-Part 1: Offline forward and adjoint transport models

Presenter : Niwa Y., Tomita H., Satoh M., Imasu R., Sawa Y., Tsuboi K., Matsueda H., Machida T., Sasakawa M., Belan B., Saigusa N.
Title : , Geoscientific Model Development, 10(3):1157-1174 (2017)
Original Paper
Methane fluxes in the high northern latitudes for 2005-2013 estimated using a Bayesian atmospheric inversion

Presenter : Thompson R.L. , Sasakawa M., Machida T., Aalto T., Worthy D., Lavric J.V. , Myhre C.L., Stohl A.
Title : , Atmospheric Chemistry and Physics, 17(5):3553-3572 (2017)
Original Paper
Temporal characteristics of CH4 vertical profiles observed in the West Siberian Lowland over Surgut from 1993 to 2015 and Novosibirsk from 1997 to 2015

Presenter : Sasakawa M., Machida T., Ishijima K., Arshinov M., Patra P.K., Ito A., Aoki S., Petrov V.
Title : , Journal of Geophysical Research: Atmospheres (2017)
Original Paper
Adjoint of the global Eulerian-Lagrangian coupled atmospheric transport model (A-GELCA v1.0): development and validation

Presenter : Belikov D.A. , Maksyutov S., Yaremchuk A., Ganshin A., Kaminski T., Blessing S., Sasakawa M., Gomez-Pelaez A.J., Starchenko A.
Title : , Geoscientific Model Development, 9(2):749-764 (2016)
Original Paper
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?

Presenter : Tan Z., Zhuang Q., Henze D.K. , Frankenberg C., Dlugokencky E., Sweeney C., Turner A.J. , Sasakawa M., Machida T.
Title : , Atmospheric Chemistry and Physics, 16(19):12649-12666 (2016)
Original Paper
Comparison of the data-driven top-down and bottom-up global terrestrial CO2 exchanges: GOSAT CO2 inversion and empirical eddy flux upscaling

Presenter : Kondo M., Ichii K., Takagi H., Sasakawa M.
Title : , Journal of Geophysical Research: Biogeosciences, 120:1226-1245 (2015)
Original Paper
Natural and anthropogenic methane fluxes in Eurasia: a mesoscale quantification by generalized atmospheric inversion

Presenter : Berchet A., Pison I., Chevallier F., Paris J.-D. , Bousquet P. , Bonne J.-L. , Arshinov M.Y., Belan B.D., Cressot C. , Davydov D.K., Dlugokencky E.J., Fofonov A. V., Galanin A. , Lavric J., Machida T., Parker R., Sasakawa M., Spahni R., Stocker B.D., Winderlich J.
Title : , Biogeosciences, 12:5393-5414 (2015)
Other Publications
Comparison of GOSAT SWIR and Aircraft Measurements of XCH4 over West Siberia

Presenter : Ono A., Hayashida S., Sugita T., Machida T., Sasakawa M., Arshinov M.
Title : , SOLA, 11:160-164 (2015)
Original Paper
Natural and anthropogenic methane fluxes in Eurasia: a meso-scale quantification by generalized atmospheric inversion

Presenter : A. Berchet, I. Pison, F. Chevallier, J.-D. Paris, P. Bousquet, J.-L. Bonne, M. Yu. Arshinov, B. D. Belan, C. Cressot, D. K. Davydov, E. J. Dlugokencky, A. V. Fofonov, A. Galanin, J. Lavrič, Machida T., R. Parker, Sasakawa M., R. Spahni, B. D. Stocker, J. Winderlich
Title : , Biogeosciences Discussions, 11:14587-14637 (2014)
Original Paper
Aircraft and tower measurements of CO2 concentration in the planetary boundary layer and the lower free troposphere over southern taiga in West Siberia:Long-term records from 2002 to 2011

Presenter : Sasakawa M., Machida T., Tsuda N., Arshinov M., Davydov D., Fofonov A., Krasnov O.
Title : , JOURNAL OF GEOPHYSICAL RESEARCH: ATMOSPHERES, 118:1-10 (2013)
Original Paper
Carbon flux estimation for Siberia by inverse modeling constrained by aircraft and tower CO2 measurements

Presenter : Saeki T., Maksyutov S., Sasakawa M., Machida T., Arshinov M., Tanｓ P., Conway T.J., Saito M., Valsala V., Oda T., Andres R.J., Belikov D.
Title : , Journal of Geophysical Research Atmospheres, 118(2):1100-1122 (2013)
Original Paper
Annual variation of CH4 emissions from the middle taiga in West Siberian Lowland (2005-2009): a case of high CH4 flux and precipitation rate in the summer of 2007

Presenter : Sasakawa M., Ito A., Machida T., Tsuda N., Niwa Y., Davydov D., Fofonov A., Arshinov M.
Title : , Tellus B, 64(17514): (2012)
Annual variation of methane emissions from forested bogs in West Siberia (2005-2009): A case of high CH4 and precipitation rate in the summer of 2007

Presenter : Sasakawa M., Ito A., Machida T., Tsuda N., Niwa Y., Davydov D., Fofonov A., Arshinov M.
Title : , Atmos.Chem.Phys.Discuss., (10):27759-27776 (2010)
Original Paper
Continuous measurements of methane from a tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T., Tsuda N., Suto H., Arshinov M., Davydov D., Fofonov A., Krasnov O., Saeki T., Koyama Y., Maksyutov S.
Title : , Tellus B, 62(5):403-416 (2010)

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Melt period methane emissions in northern high latitude wetlands are governed by the length of the period and presence of permafrost

Presenter : Hyvarinen S., Tenkanen M.K., Tsuruta A., Erkkila A., Rautiainen K., Aaltonen H., Sasakawa M., Aalto T.
Title : , Atmospheric Chemistry and Physics, 26(10):7555-7587 (2026)
Global Methane Budget 2000-2020

Presenter : Saunois M., Martinez A., Poulter B., Zhang Z., Raymond P. A., Regnier P., Canadell J.G., Jackson R.B., Patra P.K., Bousquet P., Ciais P., Dlugokencky E.J., Lan X., Allen G.H., Bastviken D., Beerling D.J., Belikov D.A., Blake D.R., Castaldi S., Crippa M., Deemer B.R., Dennison F., Etiope G., Gedney N., Hoglund-Isaksson L., Holgerson M.A., Hopcroft P.O., Hugelius G., Ito A., Jain A.K., Janardanan Achari R., Johnson M.S., Kleinen T., Krummel P.B., Lauerwald R., Li T., Liu X., McDonald K.C., Melton J.R., Muhle J., Muller J., Murguia-Flores F., Niwa Y., Noce S., Pan S., Parker R.J., Peng C., Ramonet M., Riley W. J., Rocher-Ros G., Rosentreter J.A., Sasakawa M., Segers A., Smith S.J., Stanley E.H., Thanwerdas J., Tian H., Tsuruta A., Tubiello F.N., Weber T.S., van der Werf G.R., Worthy D.E.J., Xi Y., Yoshida Y., Zhang W., Zheng B., Zhu Q., Zhu Q., Zhuang Q.
Title : , Earth System Science Data, 17(5):1873-1958 (2025)
Long-term and interannual variations of atmospheric methane observed by the NIES and collaborative observation networks

Presenter : Umezawa T., Tohjima Y., Terao Y., Sasakawa M., Mueller A., Saeki T., Machida T., Nakaoka S., Nara H., Nomura S., Nishihashi M., Mukai H., Frey M., Morino I., Ohyama H., Yoshida Y., Zeng J., Noda H., Saito M., Matsunaga T., Sugita T., Tanimoto H., Niwa Y., Ito A., Yamashita Y., Shirai T., Ishizawa M., Ishijima K., Tsuboi K., Sawa Y., Matsueda H.
Title : , Progress in Earth and Planetary Science, 12(39): (2025)
Revised methodology for CO2 and CH4 measurements at remote sites using a working standard-gas-saving system

Presenter : Sasakawa M., Tsuda N., Machida T., Arshinov M., Davydov D., Fofonov A., Belan B.
Title : , Atmospheric Measurement Techniques, 18(8):1717-1730 (2025)
Multi-observational estimation of regional and sectoral emission contributions to the persistent high growth rate of atmospheric CH4 for 2020-2022

Presenter : Niwa Y., Tohjima Y., Terao Y., Saeki T., Ito A., Umezawa T., Yamada K., Sasakawa M., Machida T., Nakaoka S., Nara H., Tanimoto H., Mukai H., Yoshida Y., Morimoto S., Takatsuji S., Tsuboi K., Sawa Y., Matsueda H., Ishijima K., Fujita R., Goto D., Lan X., Schuldt K., Heliasz M., Biermann T., Chmura L., Necki J., Xueref-Remy I., Sferlazzo
Title : , Atmospheric Chemistry and Physics, 25:6757-6785 (2025)
Efficient use of a Lagrangian particle dispersion model for atmospheric inversions using satellite observations of column mixing ratios

Presenter : Schneider P., Thompson R.L., Krishnankutty N., Pisso I., Schneider P., Stebel K., Sasakawa M., Stohl A., Platt S.M.
Title : , Atmospheric Chemistry and Physics, 25(19):12737-12751 (2025)
Observed APO Seasonal Cycle in the Pacific: Estimation of Autumn O2 Oceanic Emissions

Presenter : Tohjima Y., Shirai T., Ishizawa M., Mukai H., Machida T., Sasakawa M., Terao Y., Tsuboi K., Takao S., Nakaoka S.
Title : , Global Biogeochemical Cycles, 38: (2024)
Near-real-time estimation of fossil fuel CO2 emissions from China based on atmospheric observations on Hateruma and Yonaguni Islands, Japan

Presenter : Tohjima Y., Niwa Y., Patra P.K., Mukai H., Machida T., Sasakawa M., Tsuboi K., Saito K., Ito A.
Title : , Progress in Earth and Planetary Science (2023)
Autumn cooling paused increased CO2 release in central Eurasia

Presenter : Kondo M., Sasakawa M., Machida T., Arshinov M., Hiyama T.
Title : , Nature Climate Change, 13:334-337 (2023)
Estimating methane emissions in the Arctic nations using surface observations from 2008 to 2019

Presenter : Wittig S., Berchet A., Pison I., Saunois M., Thanwerdas J., Martinez A., Paris J.D., Machida T., Sasakawa M., Worthy D.E.J., Lan X., Thompson R.L., Sollum E., Arshinov M.
Title : , Atmospheric Chemistry and Physics, 23(11):6457-6485 (2023)
Forward and Inverse Modelling of Atmospheric Nitrous Oxide Using MIROC4-Atmospheric Chemistry-Transport Model

Presenter : Patra P. K., Dlugokencky E. J., Elkins J. W., Dutton G. S., Tohjima Y., Sasakawa M., Ito A., Weiss R. F., Manizza M., Prinn R. G., Bianchi D., Nevison C., Solazzo E., Lee H., Joo S., Kort E. A., Maity S., Takigawa M.
Title : , Journal of the Meteorological Society of Japan. Ser. II, 100(2):361-386 (2022)
Estimating emissions of methane consistent with atmospheric measurements of methane and δ13C of methane

Presenter : Basu S., Lan X., Dlugokencky E., Michel S., Schwietzke S., Miller J.B., Bruhwiler L., Oh Y., Tans P.P., Apadula F., Gatti L.V., Jordan A., Neck J., Sasakawa M., Morimoto S., Iorio T.D., Lee H., Arduini J., Manca G.
Title : , Atmospheric Chemistry and Physics, 22:15351-15377 (2022)
Measurement report: Regional characteristics of seasonal and long-term variations in greenhouse gases at Nainital, India, and Comilla, Bangladesh

Presenter : Nomura S., Naja M., Ahmed M.K., Mukai H., Terao Y., Machida T., Sasakawa M., Patra P. K.
Title : , Atmospheric Chemistry and Physics, 21:16427-16452 (2021)
Siberian and temperate ecosystems shape Northern Hemisphere atmospheric CO2 seasonal amplification

Presenter : Lin X., Rogers B.M., Sweeney C., Chevallier F., Arshinov M., Dlugokencky E., Machida T., Sasakawa M., Tans P., Keppel-Aleks G.
Title : , Proceedings of the National Academy of Sciences of the United States of America, 1-9 (2020)
Detection of fossil-fuel CO2 plummet in China due to COVID-19 by observation at Hateruma

Presenter : Tohjima Y., Patra P. K., Niwa Y., Mukai H., Sasakawa M., Machida T.
Title : , Scientific Reports (2020)
Analysis of the diurnal, weekly, and seasonal cycles and annual trends in atmospheric CO2 and CH4 at tower network in Siberia from 2005 to 2016

Presenter : Belikov D., Arshinov M., Belan B., Davydov D., Fofonov A., Sasakawa M., Machida T.
Title : , Atmosphere, 10(11): (2019)
Methane Emission Estimates by the Global High-Resolution Inverse Model Using National Inventories

Presenter : Wang F., Maksyutov S., Tsuruta A., Janardanan achari R., Ito A., Sasakawa M., Machida T., Morino I., Yoshida Y., Kaiser J.W., Janssens-Maenhout G., Dlugokencky E.J., Mammarella I., Lavric J.V., Matsunaga T.
Title : , Remote Sensing, 11（21）(2489): (2019)
Country-Scale Analysis of Methane Emissions with a High-Resolution Inverse Model Using GOSAT and Surface Observations

Presenter : Janardanan achari R., Maksyutov S., Tsuruta A., Wang F., Tiwari Y.K., Valsala V., Ito A., Yoshida Y., Kaiser J.W., Janssens-Maenhout G., Arshinov M., Sasakawa M., Tohjima Y., Worthy D.E.J., Dlugokencky E.J., Ramonet M., Arduini J., Lavric J.V., Piacentino S., Krummel P.B., Langenfelds R.L., Mammarella I., Matsunaga T.
Title : , Remote Sensing, 12(3）(375): (2019)
A global synthesis inversion analysis of recent variability in CO2 fluxes using GOSAT and in situ observations

Presenter : Wang J.S., Kawa S.R., Collatz G.J., Sasakawa M., Gatti L.V., Machida T., Liu Y., Manyin M.E.
Title : , Atmospheric Chemistry and Physics, 18(15): (2018)
Three-dimensional methane distribution simulated with FLEXPART 8-CTM-1.1 constrained with observation data

Presenter : Groot Zwaaftink C.D., Henne S., Thompson R.L., Dlugokencky E.J., Machida T., Paris J.D., Sasakawa M., Segers A., Sweeney C., Stohl A.
Title : , Geoscientific Model Development, 11(11):4469-4487 (2018)
Impact of Siberian observations on the optimization of surface CO2 flux

Presenter : Kim J., Kim H.M., Cho C.H., Boo K.O., Jacobson A.R., Sasakawa M., Machida T., Arshinov M., Fedoseev N.
Title : , Atmospheric Chemistry and Physics, 17(4):2881-2899 (2017)
A 4D-Var inversion system based on the icosahedral grid model (NICAM-TM 4D-Var v1.0)-Part 1: Offline forward and adjoint transport models

Presenter : Niwa Y., Tomita H., Satoh M., Imasu R., Sawa Y., Tsuboi K., Matsueda H., Machida T., Sasakawa M., Belan B., Saigusa N.
Title : , Geoscientific Model Development, 10(3):1157-1174 (2017)
Methane fluxes in the high northern latitudes for 2005-2013 estimated using a Bayesian atmospheric inversion

Presenter : Thompson R.L. , Sasakawa M., Machida T., Aalto T., Worthy D., Lavric J.V. , Myhre C.L., Stohl A.
Title : , Atmospheric Chemistry and Physics, 17(5):3553-3572 (2017)
Temporal characteristics of CH4 vertical profiles observed in the West Siberian Lowland over Surgut from 1993 to 2015 and Novosibirsk from 1997 to 2015

Presenter : Sasakawa M., Machida T., Ishijima K., Arshinov M., Patra P.K., Ito A., Aoki S., Petrov V.
Title : , Journal of Geophysical Research: Atmospheres (2017)
Adjoint of the global Eulerian-Lagrangian coupled atmospheric transport model (A-GELCA v1.0): development and validation

Presenter : Belikov D.A. , Maksyutov S., Yaremchuk A., Ganshin A., Kaminski T., Blessing S., Sasakawa M., Gomez-Pelaez A.J., Starchenko A.
Title : , Geoscientific Model Development, 9(2):749-764 (2016)
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?

Presenter : Tan Z., Zhuang Q., Henze D.K. , Frankenberg C., Dlugokencky E., Sweeney C., Turner A.J. , Sasakawa M., Machida T.
Title : , Atmospheric Chemistry and Physics, 16(19):12649-12666 (2016)
Comparison of the data-driven top-down and bottom-up global terrestrial CO2 exchanges: GOSAT CO2 inversion and empirical eddy flux upscaling

Presenter : Kondo M., Ichii K., Takagi H., Sasakawa M.
Title : , Journal of Geophysical Research: Biogeosciences, 120:1226-1245 (2015)
Natural and anthropogenic methane fluxes in Eurasia: a mesoscale quantification by generalized atmospheric inversion

Presenter : Berchet A., Pison I., Chevallier F., Paris J.-D. , Bousquet P. , Bonne J.-L. , Arshinov M.Y., Belan B.D., Cressot C. , Davydov D.K., Dlugokencky E.J., Fofonov A. V., Galanin A. , Lavric J., Machida T., Parker R., Sasakawa M., Spahni R., Stocker B.D., Winderlich J.
Title : , Biogeosciences, 12:5393-5414 (2015)
Natural and anthropogenic methane fluxes in Eurasia: a meso-scale quantification by generalized atmospheric inversion

Presenter : A. Berchet, I. Pison, F. Chevallier, J.-D. Paris, P. Bousquet, J.-L. Bonne, M. Yu. Arshinov, B. D. Belan, C. Cressot, D. K. Davydov, E. J. Dlugokencky, A. V. Fofonov, A. Galanin, J. Lavrič, Machida T., R. Parker, Sasakawa M., R. Spahni, B. D. Stocker, J. Winderlich
Title : , Biogeosciences Discussions, 11:14587-14637 (2014)
Aircraft and tower measurements of CO2 concentration in the planetary boundary layer and the lower free troposphere over southern taiga in West Siberia:Long-term records from 2002 to 2011

Presenter : Sasakawa M., Machida T., Tsuda N., Arshinov M., Davydov D., Fofonov A., Krasnov O.
Title : , JOURNAL OF GEOPHYSICAL RESEARCH: ATMOSPHERES, 118:1-10 (2013)
Carbon flux estimation for Siberia by inverse modeling constrained by aircraft and tower CO2 measurements

Presenter : Saeki T., Maksyutov S., Sasakawa M., Machida T., Arshinov M., Tanｓ P., Conway T.J., Saito M., Valsala V., Oda T., Andres R.J., Belikov D.
Title : , Journal of Geophysical Research Atmospheres, 118(2):1100-1122 (2013)
Annual variation of CH4 emissions from the middle taiga in West Siberian Lowland (2005-2009): a case of high CH4 flux and precipitation rate in the summer of 2007

Presenter : Sasakawa M., Ito A., Machida T., Tsuda N., Niwa Y., Davydov D., Fofonov A., Arshinov M.
Title : , Tellus B, 64(17514): (2012)
Continuous measurements of methane from a tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T., Tsuda N., Suto H., Arshinov M., Davydov D., Fofonov A., Krasnov O., Saeki T., Koyama Y., Maksyutov S.
Title : , Tellus B, 62(5):403-416 (2010)

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Comparison of GOSAT SWIR and Aircraft Measurements of XCH4 over West Siberia

Presenter : Ono A., Hayashida S., Sugita T., Machida T., Sasakawa M., Arshinov M.
Title : , SOLA, 11:160-164 (2015)

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Research Result (Presentation)

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Research Presentation
Research Lecture

Research Presentation
Evaluation of gridded wetland methane flux datasets with atmospheric CH4 simulations over Western Siberia

Presenter : Nogovitcyn A., Sasakawa M., Maksyutov S., Machida T., Machida T., Taguchi T., Qin Q., Terentieva I., Glagolev M., Glagolev M., Sabrekov A.
Name of Society : JpGU-AGU Joint Meeting 2026 (2026)
Name of Proceedings : Abstracts, MIS02:11
Research Presentation
Decadal Trends and Satellite Validation of XCO2 and XCH4 over Western Siberia Using Constructed Vertical Profiles

Presenter : Qin Q., Sasakawa M., Machida T., Machida T., Taguchi T., Nogovitcyn A.
Name of Society : JpGU-AGU Joint Meeting 2026 (2026)
Name of Proceedings : Abstracts, ACG63:P01
Research Presentation
Methane emission sources in South Asia inferred from observations of stable carbon isotope ratio of atmospheric methane

Presenter : Terao Y., Umezawa T., Ahmed M.K., Naja M., Machida T., Sasakawa M., Rani S., Mukai H., Patra P.K.
Name of Society : 22nd Annual Meeting of Asia Oceania Geosciences Society (AOGS2025) (2025)
Name of Proceedings : -
Research Presentation
Urban CO2 simulations for the Greater Tokyo Area based on high-resolution modeling and comparison with tower observation network

Presenter : Yang Z., Terao Y., Lauvaux T., Abdallah C, Oda T., Nishihashi M., Saito M., Ishidoya S., Sugawara H., Machida T., Sasakawa M., Tohjima Y.
Name of Society : The 21st International Workshop on Greenhouse Gas Measurements from Space (IWGGMS-21) (2025)
Name of Proceedings : Abstracts
Research Presentation
Inverse analysis with in-situ/flask and GOSAT observations to disentangle regional and sectoral emission contributions to the surge of atmospheric CH4 for 2020-2022

Presenter : Niwa Y., Tohjima Y., Terao Y., Saeki T., Ito A., Umezawa T., Yamada K., Sasakawa M., Machida T., Nakaoka S., Nara H., Tanimoto H., Mukai H., Yoshida Y., Morimoto S., Takatsuji S., Tsuboi K., Sawa Y., Matsueda H., Ishijima K., Fujita R., Goto D., Lan X., Schuldt K., Heliasz M., Biermann T., Chmura L., Necki J., Xueref-Remy I., Sferlazzo D.
Name of Society : IWGGMS-21 (2025)
Name of Proceedings : Abstracts
Research Presentation
Examination of anthropogenic CO2 emission inventories using ground-based observations and regional model simulations over the Tokyo Megacity

Presenter : Yang Z., Terao Y., Lauvaux T., Abdallah C., Oda T., Nishihashi M., Saito M., Ishidoya S., Sugawara H., Machida T., Sasakawa M., Tohjima Y.
Name of Society : Japan Geoscience Union Meeting 2025 (2025)
Name of Proceedings : Abstracts
Research Presentation
Emission estimation of CO2 over major cities of Japan using NICAM and WRF-GHG

Presenter : BISHT J., Niwa Y., Nakaoka S., Terao Y., Sasakawa M., Tanimoto H., Machida T.
Name of Society : The 2025 Autumn Meeting of the Meteorological Society of Japan (2025)
Name of Proceedings : 2025 年度秋季大会講演予稿集, P(359):590
Research Lecture
Validation of a new high-resolution CH4 emission dataset for Russian wetlands

Presenter : Nogovitcyn A., Sasakawa M., Maksyutov S., Machida T., Taguchi T., Qin Q.
Name of Society : The Eighth International Symposium on Arctic Research (2025)
Name of Proceedings : ISAR8_program, R1-O-03
Research Presentation
Decadal variations in vertical profiles of atmospheric carbon dioxide estimated from a combination of tower, aircraft, and satellite measurements in West Siberia

Presenter : Qin Q., Sasakawa M., Machida T., Taguchi T., Nogovitcyn A.
Name of Society : 日本地球惑星科学連合2025年大会 (2025)
Name of Proceedings : -
Research Presentation
Comparative performance of global wetland methane flux products in simulating atmospheric methane concentrations over Western Siberia

Presenter : Nogovitcyn A., Sasakawa M., Maksyutov S., Machida T., Taguchi T., Qin Q.
Name of Society : JpSAC Annual Meeting 2025 (2025)
Name of Proceedings : Abstracts, O2-10
Research Presentation
Decadal Variations of Total Column Carbon Dioxide and Methane in Western Siberia Estimated from a Combination of Tower and Aircraft Measurements

Presenter : Qin Q., Sasakawa M., Machida T., Taguchi T., Nogovitcyn A.
Name of Society : JpSAC Annual Meeting 2025 (2025)
Name of Proceedings : Abstracts, O2-11
Research Presentation
The next stage of observation project for atmospheric greenhouse gases by commercial aircraft -CONTRAIL-

Presenter : Machida T., Niwa Y., Tsu, Umezawa T., Ishijima K., Fujita R., Matsueda H., Sasakawa M., Goto D., Murayama S., Morimoto S.
Name of Society : 11th International Carbon Dioxide Conference (2024)
Name of Proceedings : -
Research Presentation
Monitoring megacity CO2 emissions using long-term atmospheric observations from commercial airliners

Presenter : Fujita R., Machida T., Ishijima K., Niwa Y., Umezawa T., Matsueda H., Tsuboi K., Sasakawa M., Sawa Y., Oda T.
Name of Society : 11th International Carbon Dioxide Conference (2024)
Name of Proceedings : -
Research Presentation
Fundamental environment for greenhouse gas monitoring at the National Institute for Environmental Studies

Presenter : Sasakawa M., Machida T.
Name of Society : 22nd WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Tracers Measurement Techniques (GGMT-2024) (2024)
Name of Proceedings : -
Research Presentation
Carbon and hydrogen isotope ratios of methane in the upper troposhere/lowermost stratosphere(UT/LMS) observed by commercial airliners

Presenter : Fujita R., Morimoto S., Machida T., Tsuboi K., Matsueda H., Ishijima K., Umezawa T., Niwa Y., Sasakawa M., Goto D., Inai Y., Aoki S., Nakazawa T.
Name of Society : 22nd WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Tracers Measurement Techniques (GGMT-2024) (2024)
Name of Proceedings : -
Research Presentation
Understanding the impact of high-temperature events on carbon balance in northern mid-to-high latitude regions

Presenter : Taguchi T., Kondo M., Ichii K., Sasakawa M.
Name of Society : 11th International Carbon Dioxide Conference (2024)
Name of Proceedings : -
Research Presentation
An efficient use of a Lagrangian transport model for atmospheric inversions using satellite observations: case study using TROPOMI to estimate CH4 emissions over Siberia

Presenter : Krishnankutty N. , Thompson R.N., Pisso I., Schneider P., Stebel K., Sasakawa M., Platt S.M.
Name of Society : EGU General Assembly 2024 (2024)
Name of Proceedings : -, 24-3175
Research Presentation
Assessing the Long-Range Transport of Persistent Organic Pollutants and Chemical Reactions of Heavy Metals in Aerosols over Hateruma Island, Japan

Presenter : Ito L., Kawakami M., Sasakawa M., Takazawa Y., Takahashi Y., Tokai A.
Name of Society : AGU24 (2024)
Name of Proceedings : -
Research Presentation
Multi-observational estimation of regional and sectoral emission contributions to the persistent high growth rate of atmospheric CH4 for 2020–2022

Presenter : Niwa Y., Tohjima Y., Terao Y., Saeki T., Ito A., Umezawa T., Yamada K., Sasakawa M., Machida T., Nakaoka S., Nara H., Tanimoto H., Mukai H., Yoshida Y., Morimoto S., Saito K., Tsuboi K., Sawa Y., Matsueda H., Ishijima K., Fujita R., Goto D., Lan X., Schuldt K., Heliasz M., Biermann T., Chmura L., Necki J., Xueref-Remy I.
Name of Society : AGU Fall Meeting 2024 (2024)
Name of Proceedings : -
Research Presentation
Fundamental environment for greenhouse gas monitoring at the National Institute for Environmental Studies

Presenter : Sasakawa M., Machida T.
Name of Society : Workshop on Global and National Greenhouse Gas Monitoring Initiatives, KRISS, Daejeon, 23rd - 24th October 2024 (2024)
Name of Proceedings : -
Research Presentation
Growing emissions and Asian monsoon as dominant factors for atmospheric greenhouse gas variations over Asia

Presenter : Umezawa T., Terao Y., Machida T., Niwa Y., Sasakawa M., Ito A., Matsueda H., Tsuboi K., Ishijima K., Fujita R., Chandra N., Patra P. K., Aoki S., Nakazawa T., Morimoto S.
Name of Society : The 5th Atmospheric Composition and the Asian Monsoon (ACAM) workshop (2023)
Name of Proceedings : -
Research Presentation
Methane sources in South Asia inferred from observations of stable carbon isotope ratio of atmospheric methane

Presenter : Terao Y., Umezawa T., Ahmed M.K. , Manish Naja, Nomura S., Machida T., Sasakawa M., Mukai H., Patra P.K. , Rani S.
Name of Society : The 5th Atmospheric Composition and the Asian Monsoon (ACAM) workshop (2023)
Name of Proceedings : -
Research Presentation
Top-down estimate of methane emissions from Siberia using a Bayesian atmospheric inversion

Presenter : Marthinsen E., Thompson R.L., Pisso I., Muller J., Sasakawa M., Zaehle S.
Name of Society : Ninth International Symposium on Non-CO2 Greenhouse Gases (2023)
Name of Proceedings : -
Research Presentation
Observation activities for atmospheric greenhouse gases by CONTRAIL and other platforms by NIES and collaborators

Presenter : Machida T., Niwa Y., Umezawa T., Tsuboi K., Ishijima K., Fujita R., Matsueda H., Sasakawa M., Terao Y., Tohjima Y., Nara H., Saito T., Nakaoka S., Takao S., Aramaki T., Takahashi Y., Hirata R., Mueller A., Srivastava P., Morino I., Ohyama H., Frey M., Noda H., Mukai H., Shirai T., Tanimoto H.
Name of Society : WMO International Greenhouse Gas Monitoring Symposium (2023)
Name of Proceedings : -
Research Presentation
Measurements of stable carbon isotope ratio of methane at Hateruma Station, Japan

Presenter : Umezawa T., Terao Y., Tohjima Y., Saito T., Sasakawa M., Mukai H.
Name of Society : The 21st expert meeting on Greenhouse Gas Measurement Techniques (WMO GAW GGMT-2022) (2022)
Name of Proceedings : Abstracts
Research Presentation
Assessment of the stability and relationships between the NIES-09, SIO-X12, and WMO-X2019 CO2 scales

Presenter : Crotwell A.M., Keeling R.F., Sasakawa M., Walker S., Hall B.D.
Name of Society : METROLOGY FOR CLIMATE ACTION (2022)
Name of Proceedings : -
Research Presentation
Evaluation of strategies for assessing CO2 inter‐laboratory offsets

Presenter : Jordan A., Levin I., Hammer S., Yver C., Ramonet M., Langenfelds R. L., Sasakawa M., Crotwell A. M., Dlugokencky E., Scheeren B., Chen H., Rauh M.
Name of Society : METROLOGY FOR CLIMATE ACTION (2022)
Name of Proceedings : -
Research Presentation
WCC and QA/SAC activities and GHG observation by JMA

Presenter : Tohjima Y., Machida T., Terao Y., Sasakawa M., Takatsuji S., Kameoka Y., Kinoshita A., Saito A., Saito K., Ushio N., Yukita K., Yoshida M., Fujiwara S., Iwaki M., Fukuda Y., Sawa Y., Tsuboi K., Ishijima K., Murayama S.
Name of Society : The 21st expert meeting on Greenhouse Gas Measurement Techniques (2022)
Name of Proceedings : Abstracts, 63
Research Presentation
The Sausage ICP: 20 years of inter-laboratory ask-air comparison data

Presenter : Jordan A., Levin I., Hammer S., Langenfelds R.L., Yver-Kwok C., Ramonet M., Chen H., Scheeren B., Sasakawa M., Rauh M., Crotwell A.M., Dlugokencky E., Petron G., Leuenberger M.
Name of Society : GGMT-2022 (2022)
Name of Proceedings : Abstracts, 99-100
Research Presentation
Inverse modeling of the carbon sink in the northern boreal regions and comparison with bottom-up data

Presenter : Maksyutov S., Oda T., Zeng J., Sasakawa M., Machida T., Arshinov M., Matsunaga T.
Name of Society : Japan Geoscience Union Meeting 2022 (2022)
Name of Proceedings : -
Research Presentation
Recovery of CO2 emissions from China after COVID-19 lockdown estimated from the atmospheric observation at Yaeyama Islands

Presenter : Tohjima Y., Niwa Y., Mukai H., Sasakawa M., Machida T., Patra P. K., Tsuboi K., Saito K.
Name of Society : Japan Geoscience Union Meeting 2022 (2022)
Name of Proceedings : -
Research Presentation
Long term trend of summertime CO2 uptake by land biosphere in Northern Eurasia

Presenter : Shirai T., Ishizawa M., Sasakawa M., Ito A., Machida T., Maksyutov S.
Name of Society : Japan Geoscience Union Meeting 2022 (2022)
Name of Proceedings : -
Research Presentation
Aircraft monitoring for atmospheric greenhouse gases over Siberia

Presenter : Machida T., Sasakawa M., Arshinov M., Mitin S., Maximov T.
Name of Society : 日本地球惑星科学連合2022年大会 (2022)
Name of Proceedings : -
Research Presentation
Near-real-time estimation of fossil fuel CO2 emissions from China based on atmospheric observations at remote islands in Japan

Presenter : Tohjima Y., Niwa Y., Patra P.K., Mukai H., Machida T., Sasakawa M., Tsuboi K., Saito K., Ito A.
Name of Society : AGU Fall Meeting 2022 (2022)
Name of Proceedings : -
Research Presentation
Increasing trend of summertime CO2 uptake by land biosphere in Northern Eurasia for 2002-2017

Presenter : Shirai T., Ishizawa M., Sasakawa M., Ito A., Machida T., Maksyutov S.
Name of Society : The 27th Symposium on Atmospheric Chemistry (2022)
Name of Proceedings : Book of Abstracts, O1-05
Research Presentation
Evaluation of a revised global high-resolution inverse model with CO2 observations over Siberia.

Presenter : Maksyutov S., Sasakawa M., Machida T., Oda T., Zeng J., Matsunaga T., Kaiser J.W., Arshinov M., Belan B., Dlugokencky E.
Name of Society : Japan Geoscience Union Meeting 2021 (2021)
Name of Proceedings : -
Research Presentation
Changes in the atmospheric CO2/CH4 variability in the East Asian outflow region caused by plummet of fossil fuel-derived CO2 in China due to COVID-19 outbreak

Presenter : Tohjima Y., Niwa Y., Mukai H., Sasakawa M., Machida T., Nakaoka S., Patra P. K.
Name of Society : Japan Geoscience Union Meeting 2021 (2021)
Name of Proceedings : -, ACG34-03
Research Presentation
Top-down estimate of the terrestrial carbon balance for northern boreal regions suggests larger carbon sink in Siberia

Presenter : Maksyutov S., Oda T., Zeng J., Kaiser J.W., Sasakawa M., Machida T., Arshinov M., Belan B.D., Yoshida Y., Matsunaga T.
Name of Society : AGU Fall Meeting 2021 (2021)
Name of Proceedings : -
Research Presentation
Top-down estimation of surface terrestrial CO2 flux in Northern Eurasia

Presenter : Shirai T., Misa I., Sasakawa M., Ito A., Machida T., Maksyutov S.
Name of Society : JpGU-AGU Joint Meeting 2020 (2020)
Name of Proceedings : -
Research Presentation
Recent stagnation of CH4 emission growth from East Asia based on the analysis of synoptic variations of atmospheric CH4 and CO2 observed at Hateruma Island

Presenter : Tohjima Y., Zeng J., Ito A., Naveen C., Niwa Y., Mukai H., Shirai T., Sasakawa M., Patra P. K., Machida T.
Name of Society : JpGU-AGU Joint Meeting 2020 (2020)
Name of Proceedings : -, AAS07-P02
Research Presentation
Natural and anthropogenic methane emissions in West Siberia estimated using a wetland inventory, GOSAT and a regional tower network

Presenter : Maksyutov S., Sasakawa M., Janardanan achari R., Wang F., Tsuruta A., Terentieva I., Sabrekov A., Glagolev M., Machida T., Arshinov M., Davydov D., Krasnov O., Belan B., Dlugokencky E., Lavric J.V., Ito A., Janssens-Maenhout G., Kaiser J., Yoshida Y., Matsunaga T.
Name of Society : 22nd EGU General Assembly (2020)
Name of Proceedings : -
Research Presentation
Assessment of CH4 sources in the Arctic using regional atmospheric measurements and their link to surface emissions

Presenter : Wittig S., Berchet A., Paris Jean-Daniel., Arshinov M., Machida T., Sasakawa M., Worthy D., Pison I.
Name of Society : EGU General Assembly 2020 (2020)
Name of Proceedings : -
Research Presentation
GHGs data comparison between NIES observation network (aircrafts, Ships and stations) in the Asian Pacific area and GOSAT

Presenter : Nomura S., Mukai H., Terao Y., Machida T., Sasakawa M., Morino I.
Name of Society : The 20th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases,and Related Measurement Techniques (GGMT2019) (2019)
Name of Proceedings : Abstract, 94
Research Presentation
Working standard gas saving system for in situ CO2 and CH4 measurements and calculation method for concentrations and their uncertainty

Presenter : Sasakawa M., Tsuda N., Machida T., Arshinov M., Davydov D., Fofonov A.
Name of Society : GGMT2019 (2019)
Name of Proceedings : Abstracts
Research Presentation
Inverse modeling of anthropogenic methane emissions based on ground-based monitoring and GOSAT satellite retrievals

Presenter : Maksyutov S., Tsuruta A., Janardanan achari R., Ito A., KAISER J., Maenhout G.J., Dlugokencky E., Sasakawa M., Machida T., Yoshida Y., Matsunaga T.
Name of Society : 8th International Symposium on Non-CO2 Greenhouse Gases (NCGG8) (2019)
Name of Proceedings : -
Research Presentation
GLOBAL HIGH SPATIAL RESOLUTION METHANE ATMOSPHERIC INVERSE MODEL NIES-TMFLEXPART- VAR

Presenter : Tsuruta A., Maksyutov S., Janardanan achari R., Ito A., KAISER J., Maenhout G.J., Dlugokencky E., Sasakawa M., Machida T., Matsunaga T.
Name of Society : 8th International Symposium on Non-CO2 Greenhouse Gases (NCGG8) (2019)
Name of Proceedings : -
Research Presentation
Working standard gas saving system for in-situ CO2 and CH4 measurements and calculation method for concentrations and uncertainty

Presenter : Sasakawa M., Tsuda N., Machida T., Arshinov M., Davydov D., Fofonov A.
Name of Society : 8th International Symposium on Non-CO2 Greenhouse Gases (2019)
Name of Proceedings : Abstracts
Research Presentation
Comparing national methane emissions inventories with estimates by the global high-resolution inverse model

Presenter : Wang F., Tsuruta A., Maksyutov S., Janardanan achari R., Ito A., Sasakawa M., Machida T., Morino I., Yoshida Y., Kaiser J.W., Janssens-Maenhout G., Dlugokencky E., Matsunaga T.
Name of Society : The 15th International Workshop on Greenhouse Gas Measurements from Space (2019)
Name of Proceedings : Abstract Collection, 103
Research Presentation
Global inverse analysis of CH4 fluxes using NICAM-TM 4D-Var

Presenter : Niwa Y., Ito A., Machida T., Sasakawa M., Tohjima Y., Terao Y., Umezawa T., Morimoto S., Aoki S., Sawa Y., Tsuboi K., Matsueda H., Dlugokencky E., Harth C., Krummel P. B., Langenfelds R. L., Loh Z. M., Mühle J., O’Doherty S., Prinn R. G., Ramonet M., Salameh P., Sweeney C., Weiss R., Young D., Castaldi S., Noce S., Saunois M., Stavert A. R.
Name of Society : 日本地球惑星科学連合2019年大会 (2019)
Name of Proceedings : -
Research Presentation
Estimating regional anthropogenic methane emissions with GOSAT satellite retrievals and ground-based observations

Presenter : Maksyutov S., Tsuruta A., Janardanan achari R., Wang F., Ito A., Sasakawa M., Machida T., Morino I., Yoshida Y., kaiser J., Janssens-Maenhout G., Dlugokencky E., Matsunaga T.
Name of Society : Japan Geoscience Union Meeting 2019 (2019)
Name of Proceedings : -
Research Presentation
Inversion estimates of regional methane emissions and its trends in 2010-2017 by a global high-resolution model

Presenter : Wang F., Maksyutov S., Tsuruta A., Janardanan achari R., Ito A., Sasakawa M., Morino I., Yoshida Y., Kaiser J.W., Janssens-Maenhout G.G.A., Dlugokencky E.J., Matsunaga T.
Name of Society : American Geophysical Union Fall Meeting 2019 (2019)
Name of Proceedings : -
Research Presentation
Top-down estimates of methane emissions in Russia using regional tower network observations

Presenter : Sasakawa M., Wang F., Tsuruta A., Maksyutov S., Janardanan achari R., Ito A., Janssens-Maenhout G., Dlugokencky E.J., Arshinov M., Krasnov O., Kaiser J.W., Matsunaga T., Machida T.
Name of Society : AGU Fall Meeting2019 (2019)
Name of Proceedings : Abstracts
Research Presentation
Working standard gas saving system for in-situ CO2 and CH4 measurements and calculation method for concentrations and uncertainty

Presenter : Sasakawa M., Tsuda N., Machida T., Arshinov M., Denis D., Fofonov A.
Name of Society : Japan Geoscience Union Meeting 2018 (2018)
Name of Proceedings : -
Research Presentation
Fonovaya Observatory for comprehensive atmospheric monitoring in West Siberia:current status and future needs

Presenter : Belan B.D. , Arshinov M., Davydov D., Fofonov A., Kozlov A., Machida T., Sasakawa M., Paris J.D.
Name of Society : EGU General Assembly 2018 (2018)
Name of Proceedings : Geophysical Research Abstracts, 20(6183-1)
Research Presentation
Three-dimensional concentration fields of methane simulated with a Lagrangian model nudged with observation data

Presenter : Zwaaftink C.G., Henne S., Thompson R., Machida T., Paris J.D., Sasakawa M., Segers A., Sweeney C., Stohl A.
Name of Society : EGU General Assembly 2018 (2018)
Name of Proceedings : Geophysical Research Abstracts, 20(13946)
Research Presentation
Continuous measurement of CO2 and CH4 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A.
Name of Society : 10th International Carbon Dioxide Conference (2017)
Name of Proceedings : ICDC 10 Abstracts, 99
Research Presentation
Continuous measurement of CO2 and CH4 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A.
Name of Society : JpGU-AGU Joint Meeting 2017 (2017)
Name of Proceedings : Abstracts, (AAS11-P05)
Research Presentation
Methane budget estimates for northern high latitudes by CarbonTracker Europe-CH4

Presenter : Tsuruta A., Aalto T., Backman L., Laan-Luijkx I.T.V.D., Krol M., Spahni R., Lienert S., Houweling S., Laurila T., Hatakka J., Dlugokencky E., Worthy D., Sasakawa M., Peltola O., Mauranen A., Heiman M., Kozlova L., Crotwell A., Peters W.
Name of Society : The 2nd ICOS Science Conference (2016)
Name of Proceedings : -
Research Presentation
Methane budgets in northern latitudes during soil freezing period

Presenter : Aalto T., Kangasaho V., Tsuruta A., Rautiainen K., Backman L., Laan-Luijkx I.T.V.D., Krol M., Spahni R., Lienert S., Houweling S., Laurila T., Juha Hatakka, Worthy D., Sasakawa M., Peltola O., Mauranen A., Heimann M., Kozlova L., Dlugokencky E., Crotwell A., Peters W.
Name of Society : The 2nd ICOS Science Conference (2016)
Name of Proceedings : -
Research Presentation
Continuous measurement of CO2 and CH4 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Tsuda N., Katsumata K., Arshinov M., Davydov D., Fofonov A.
Name of Society : 日本地球惑星科学連合2016年大会 (2016)
Name of Proceedings : 同予稿集
Research Presentation
Methane fluxes in the high northern latitudes estimated using a Bayesian atmospheric inversion

Presenter : Thompson R., Stohl A., Myhre C. L., Sasakawa M., Machida T., Aalto T., Dlugokencky E., Worthy D., Skorokhod A.
Name of Society : EGU General Assembly 2016 (2016)
Name of Proceedings : Geophysical Research Abstracts, 18(11875)
Research Presentation
Changes in CO2 trends observed in the lower troposphere over West Siberia

Presenter : Belan B.D. , Machida T., Sasakawa M., Maksyutov S., Davydov D., Fofonov A., Arshinov M.
Name of Society : EGU General Assembly 2016 (2016)
Name of Proceedings : Geophysical Research Abstracts, 18(11616)
Research Presentation
Analysis of atmospheric methane from Siberian tower observation using chemistry transport model

Presenter : Ishijima K., Ishijima K., Sasakawa M., Machida T., Patra P.K., Ito A., Kumar K.R., Saeki T., Morimoto S., Aoki S., Nakazawa T.
Name of Society : GRENE北極気候変動研究事業研究成果報告会 (2016)
Name of Proceedings : 講演予稿集
Research Presentation
Continuous measurement of CO2 and CH4 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A.
Name of Society : The 22nd Symposium on Atmospheric Chemistry (2016)
Name of Proceedings : Book of Abstracts, 48
Research Presentation
COMPARISON OF CARBON DIOXIDE MIXING RATIOS FROM IN-SITU MEASUREMENTS BY NDIR AND CRDS ANALYZERS AND BOTTLE SAMPLING MEASUREMENTS AT HATERUMA ISLAND

Presenter : Katsumata K., Mukai H., Sasakawa M., Tohjima Y., Machida T., Terao Y.
Name of Society : 18th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Measurement Techniques (GGMT-2015) (2015)
Name of Proceedings : Abstracts
Research Lecture
Observation of atmospheric CH4 using aircraft platform

Presenter : Machida T., Sasakawa M., Umezawa T., Sawa Y., Matsueda H., Niwa Y., Tsuboi K., Murayama S., Morimoto S., Aoki S.
Name of Society : InGos International Conference (2015)
Name of Proceedings : Abstracts
Research Presentation
Estimating regional CH4 fluxes using ground-based and space-based observations

Presenter : Kim H., Maksyutov S., Saito M., Ito A., Belikov D., Saeki T., Morino I., Uchino O., Yoshida Y., Sasakawa M., Machida T., Yokota T.
Name of Society : 日本気象学会2015年度春季大会 (2015)
Name of Proceedings : 同予稿集, 236-236
Research Presentation
Spatial and Temporal Variability of CO2 and CH4 Concentrations in the Atmospheric Surface Layer over West Siberia

Presenter : Belan B.D., Machida T., Sasakawa M., Davydov D.K. , Fofonov A. V. , Krasnov O.A. , Maksyutov S., Arshinov M.Y.
Name of Society : European Geosciences Union General Assembly 2015 (2015)
Name of Proceedings : Geophysical Research Abstracts, 17
Research Presentation
Methane emissions in the Arctic and sub-Arctic from a Bayesian atmospheric inversion

Presenter : Thompson R., Stohl A., Myhre C.L., Sasakawa M., Machida T., Aalto T., Dlugokencky E., Worthy D.
Name of Society : European Geosciences Union General Assembly 2015 (2015)
Name of Proceedings : Geophysical Research Abstracts, 17
Research Presentation
Isolating wetland CH4 emissions using the additional constraints of 13CH4, and C2H6 in a inverse modeling framework

Presenter : Ramirez T.G.N., Marshall J., Houweling S., Dlugokencky E.J., Worthy D.E.J., Vaughn B., Simpson I., White J., Brand W.A., Sasakawa M., Nichol S., Ramonet M., Tyler S.C., Hueber J., Helmig D., Read K., Punjabi S., Gatti L.V., Krummel P., Heimann M.
Name of Society : European Geosciences Union General Assembly 2015 (2015)
Name of Proceedings : Geophysical Research Abstracts, 17
Research Presentation
Developing a high-resolution CO2 flux inversion model for global and regional scale studies

Presenter : Maksyutov S., Janardanan R., Oda T., Ito A., Saito M., Kaiser J., Belikov D., Ganshin A., Valsala V., Sasakawa M., Machida T.
Name of Society : 2015 AGU Fall Meeting (2015)
Name of Proceedings : Abstracts
Research Presentation
Inverse modeling analysis of regional methane fluxes using GOSAT retrievals in 2010-2012

Presenter : Kim H., Maksyutov S., Belikov D., Ito A., Morino I., Yoshida Y., Yokota T., Sasakawa M., Machida T.
Name of Society : 2015 AGU Fall Meeting (2015)
Name of Proceedings : Abstracts
Research Presentation
Long-term Variations of Atmospheric CH4 Concentration over Siberia Derived from Aircraft Observation

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A., Krasnov O., Patra P., Ishijima K.
Name of Society : 2015 AGU Fall Meeting (2015)
Name of Proceedings : Abstracts
Research Presentation
Estimation of methane fluxes in the high northern latitudes from a Bayesian atmospheric inversion

Presenter : Thompson R., Stohl A., Myhre C.L., Sasakawa M., Machida T., Aalto T., Dlugokencky E., Worthy D.
Name of Society : 2015 AGU Fall Meeting (2015)
Name of Proceedings : Abstracts
Research Presentation
Full Spectral Resolution Data Generation from the Cross-track Infrared Sounder on S-NPP at NOAA and its Use to Investigate Uncertainty in Methane Absorption Band Near 7.66 um

Presenter : Xiong X., Peischi J., Ryerson T., Sasakawa M., Han Y., Chen Y., Wang L., Tremblay D., Jin X., Zhou L., Liu Q., Weng F., Machida T.
Name of Society : 2015 AGU Fall Meeing (2015)
Name of Proceedings : Abstracts
Research Presentation
Aircraft observation of atmospheric greenhouse gases over Siberia

Presenter : Machida T., Sasakawa M., Vinnichenko, N., Arshinov, M., Belan, B., Fedoseev, N., Mitin, S., Matsueda, H., Sawa, Y., Niwa, Y., Tsuboi, K., Katsumata K., Murayama, S., Morimoto, S., Aoki, S.
Name of Society : Russia/Japan Joint Workshop on Environmental Investigations in West Siberia and the Arctic using a synergy of Russian Airplane-Laboratory and Japanese Satellites (2015)
Research Presentation
Long-term variations of atmospheric CH4 concentration over Siberia derived from aircraft and tower observation

Presenter : Sasakawa M., Machida T., Ito A., Tsuda K., Arshinov M., Davydov D., Fofonov A., Krasnov O., Patra P.K., Ishijima K.
Name of Society : 第21回大気化学討論会 (2015)
Name of Proceedings : 第21回大気化学討論会講演要旨集, 88
Research Presentation
Effect of Atmospheric CO2 Observations in Asia on the Optimization of Surface CO2 Flux

Presenter : Kim J., Kim H.M., Cho C., Jacobson A., Jacobson A., Sasakawa M., Machida T., Arshinov M., Fedoseev N.
Name of Society : 2014 AGU Fall Meeting (2014)
Name of Proceedings : Abstracts
Research Presentation
Long-term variations of atmospheric CH4 concentration over Siberia derived from aircraft and tower measurements

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A., Krasnov O., Fedoseev N., Nesterova M., Galanin A., Patra P., Ishijima K.
Name of Society : 7th International Symposium on Non-Co2 Greenhouse Gases (NCGG7) (2014)
Name of Proceedings : Abstracts
Research Presentation
Continuous measurement of carbon dioxide, methane, and carbon monoxide mole fractions using cavity ring-down spectroscopy at Hateruma Island

Presenter : Katsumata K., Tohjima Y., Sasakawa M., Mukai H.
Name of Society : 17th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Tracers Measurement Techniques (2013)
Name of Proceedings : Abstracts
Research Presentation
Continuous measurements of CO2 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Tsuda N., Arshinov M., Davydov D., Fofonov A., Krasnov O., Fedoseev N.
Name of Society : 9th International Carbon Dioxide Conference (2013)
Name of Proceedings : Abstracts
Research Presentation
Model resolution comparison for methane simulation in the Arctic region

Presenter : Ishijima K., Patra P.K., Ghosh A., Morimoto S., Machida T., Sasakawa M., Tohjima Y., Ito A., Aoki S., Nakazawa T.
Name of Society : Third International Symposium on the Arctic Research (2013)
Name of Proceedings : Abstracts, 128-128
Research Presentation
Observations of atmospheric greenhouse gases from a tower network and aircraft over Siberia

Presenter : Machida T., Sasakawa M., Sawa Y., Matsueda H., Morimoto S., Murayama S., Niwa Y., Tsuboi K., Aoki S.
Name of Society : Third International Symposium on the Arctic Research (2013)
Name of Proceedings : Abstracts, 137-137
Research Presentation
Carbon flux estimation for Siberia by inverse modeling constrained by aircraft and tower CO2 measurements

Presenter : Saeki T., Maksyutov S., Sasakawa M., Machida T., Arshinov M., Tans P.P., Conway T.J., Saito M., Valsala V., Oda T., Andres R.J.
Name of Society : AGU Fall Meeting 2012 (2012)
Name of Proceedings : Abstracts
Research Presentation
Continuous measurements of CO2 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Tsuda T., Arshinov M., Davydov D., Fofonov A., Krasnov O., Fedoseev N.
Name of Society : 第18回大気化学討論会 (2012)
Name of Proceedings : 第18回大気化学討論会講演要旨集, 86-86
Research Presentation
Annual variation of CH4 emissions from forested bogs in West Siberia (2005–2009): a case of high CH4 and precipitation rate in the summer of 2007

Presenter : Sasakawa M., Ito A., Machida T., Tsuda N., Niwa Y., Davydov D., Fofonov A., Arshinov M.
Name of Society : Sixth International Symposium on Non-CO2 Greenhouse Gases (NCGG-6) (2011)
Name of Proceedings : -
Research Presentation
Continuous methane measurement using 9-tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T., Tsuda N., Suto H., Arshinov M., Davydov D., Fofonov A., Krasnov O., Saeki T., Koyama Y., Maksyutov S.
Name of Society : Jpn.Geosci.Union Meet.2010 (2010)
Name of Proceedings : Abstracts
Research Presentation
Aircraft tower measurements of CO2 concentration in the planetary boundary layer and lower free troposphere over taiga in West Siberia: Long-term records from 2002 to 2010

Presenter : Sasakawa M., Machida T., Tsuda N., Shimoyama K., Arshinov M., Davydov D., Fofonov A., Krasnov O.
Name of Society : 第16回大気化学討論会 (2010)
Name of Proceedings : 同講演要旨集, 71
Research Presentation
Annual variation(2005-2009)of methane emissions from wetlands at West Siberia: Anomalous increase induced by high precipitation rate in the summer of 2007

Presenter : Sasakawa M., Ito A., Machida T., Tsuda N., Niwa Y., Arshinov M.
Name of Society : 日本気象学会2010年度秋季大会 (2010)
Name of Proceedings : 同講演予稿集, 406
Research Presentation
Continuous measurement of carbon dioxide and methane concentration using 9-tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T., Tsuda N., Suto H., Arshinov M., Davidov D., Fofonov A., Krasnov O., Saeki T., Koyama Y., Maksyutov S.
Name of Society : 8th Int.Carbon Dioxide Conf. (2009)
Name of Proceedings : Abstracts
Research Presentation
Continuous measurement of atmospheric methane concentration using 9-tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T.
Name of Society : Jpn.Geosci.Union Meet.2009 (2009)
Name of Proceedings : Abstracts, F119-P009
Research Lecture
Tropospheric methane and carbon dioxide over West Siberia: observation data analysis, surface flux inventories and transport modeling

Presenter : Maksyutov S., Machida T., Sasakawa M., Koyama Y., Saeki T., Shimoyama K., Glagolev M., Kim H., Inoue G., Fedoseev N.
Name of Society : AGU Fall Meeting 2009 (2009)
Name of Proceedings : Abstracts
Research Presentation
Continuous measurement of methane concentration using 9-tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T., Tsuda N., Suto H., Arshinov M., Davydov D., Fofonov A., Krasnov O., Saeki T., Koyama Y., Maksyutov S.
Name of Society : 第15回大気化学討論会 (2009)
Name of Proceedings : 同講演要旨集, 69

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Evaluation of gridded wetland methane flux datasets with atmospheric CH4 simulations over Western Siberia

Presenter : Nogovitcyn A., Sasakawa M., Maksyutov S., Machida T., Machida T., Taguchi T., Qin Q., Terentieva I., Glagolev M., Glagolev M., Sabrekov A.
Name of Society : JpGU-AGU Joint Meeting 2026 (2026)
Name of Proceedings : Abstracts, MIS02:11
Methane emission sources in South Asia inferred from observations of stable carbon isotope ratio of atmospheric methane

Presenter : Terao Y., Umezawa T., Ahmed M.K., Naja M., Machida T., Sasakawa M., Rani S., Mukai H., Patra P.K.
Name of Society : 22nd Annual Meeting of Asia Oceania Geosciences Society (AOGS2025) (2025)
Name of Proceedings : -
Inverse analysis with in-situ/flask and GOSAT observations to disentangle regional and sectoral emission contributions to the surge of atmospheric CH4 for 2020-2022

Presenter : Niwa Y., Tohjima Y., Terao Y., Saeki T., Ito A., Umezawa T., Yamada K., Sasakawa M., Machida T., Nakaoka S., Nara H., Tanimoto H., Mukai H., Yoshida Y., Morimoto S., Takatsuji S., Tsuboi K., Sawa Y., Matsueda H., Ishijima K., Fujita R., Goto D., Lan X., Schuldt K., Heliasz M., Biermann T., Chmura L., Necki J., Xueref-Remy I., Sferlazzo D.
Name of Society : IWGGMS-21 (2025)
Name of Proceedings : Abstracts
Comparative performance of global wetland methane flux products in simulating atmospheric methane concentrations over Western Siberia

Presenter : Nogovitcyn A., Sasakawa M., Maksyutov S., Machida T., Taguchi T., Qin Q.
Name of Society : JpSAC Annual Meeting 2025 (2025)
Name of Proceedings : Abstracts, O2-10
Decadal Variations of Total Column Carbon Dioxide and Methane in Western Siberia Estimated from a Combination of Tower and Aircraft Measurements

Presenter : Qin Q., Sasakawa M., Machida T., Taguchi T., Nogovitcyn A.
Name of Society : JpSAC Annual Meeting 2025 (2025)
Name of Proceedings : Abstracts, O2-11
The next stage of observation project for atmospheric greenhouse gases by commercial aircraft -CONTRAIL-

Presenter : Machida T., Niwa Y., Tsu, Umezawa T., Ishijima K., Fujita R., Matsueda H., Sasakawa M., Goto D., Murayama S., Morimoto S.
Name of Society : 11th International Carbon Dioxide Conference (2024)
Name of Proceedings : -
Monitoring megacity CO2 emissions using long-term atmospheric observations from commercial airliners

Presenter : Fujita R., Machida T., Ishijima K., Niwa Y., Umezawa T., Matsueda H., Tsuboi K., Sasakawa M., Sawa Y., Oda T.
Name of Society : 11th International Carbon Dioxide Conference (2024)
Name of Proceedings : -
Carbon and hydrogen isotope ratios of methane in the upper troposhere/lowermost stratosphere(UT/LMS) observed by commercial airliners

Presenter : Fujita R., Morimoto S., Machida T., Tsuboi K., Matsueda H., Ishijima K., Umezawa T., Niwa Y., Sasakawa M., Goto D., Inai Y., Aoki S., Nakazawa T.
Name of Society : 22nd WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Tracers Measurement Techniques (GGMT-2024) (2024)
Name of Proceedings : -
An efficient use of a Lagrangian transport model for atmospheric inversions using satellite observations: case study using TROPOMI to estimate CH4 emissions over Siberia

Presenter : Krishnankutty N. , Thompson R.N., Pisso I., Schneider P., Stebel K., Sasakawa M., Platt S.M.
Name of Society : EGU General Assembly 2024 (2024)
Name of Proceedings : -, 24-3175
Multi-observational estimation of regional and sectoral emission contributions to the persistent high growth rate of atmospheric CH4 for 2020–2022

Presenter : Niwa Y., Tohjima Y., Terao Y., Saeki T., Ito A., Umezawa T., Yamada K., Sasakawa M., Machida T., Nakaoka S., Nara H., Tanimoto H., Mukai H., Yoshida Y., Morimoto S., Saito K., Tsuboi K., Sawa Y., Matsueda H., Ishijima K., Fujita R., Goto D., Lan X., Schuldt K., Heliasz M., Biermann T., Chmura L., Necki J., Xueref-Remy I.
Name of Society : AGU Fall Meeting 2024 (2024)
Name of Proceedings : -
Fundamental environment for greenhouse gas monitoring at the National Institute for Environmental Studies

Presenter : Sasakawa M., Machida T.
Name of Society : Workshop on Global and National Greenhouse Gas Monitoring Initiatives, KRISS, Daejeon, 23rd - 24th October 2024 (2024)
Name of Proceedings : -
Growing emissions and Asian monsoon as dominant factors for atmospheric greenhouse gas variations over Asia

Presenter : Umezawa T., Terao Y., Machida T., Niwa Y., Sasakawa M., Ito A., Matsueda H., Tsuboi K., Ishijima K., Fujita R., Chandra N., Patra P. K., Aoki S., Nakazawa T., Morimoto S.
Name of Society : The 5th Atmospheric Composition and the Asian Monsoon (ACAM) workshop (2023)
Name of Proceedings : -
Methane sources in South Asia inferred from observations of stable carbon isotope ratio of atmospheric methane

Presenter : Terao Y., Umezawa T., Ahmed M.K. , Manish Naja, Nomura S., Machida T., Sasakawa M., Mukai H., Patra P.K. , Rani S.
Name of Society : The 5th Atmospheric Composition and the Asian Monsoon (ACAM) workshop (2023)
Name of Proceedings : -
Top-down estimate of methane emissions from Siberia using a Bayesian atmospheric inversion

Presenter : Marthinsen E., Thompson R.L., Pisso I., Muller J., Sasakawa M., Zaehle S.
Name of Society : Ninth International Symposium on Non-CO2 Greenhouse Gases (2023)
Name of Proceedings : -
The Sausage ICP: 20 years of inter-laboratory ask-air comparison data

Presenter : Jordan A., Levin I., Hammer S., Langenfelds R.L., Yver-Kwok C., Ramonet M., Chen H., Scheeren B., Sasakawa M., Rauh M., Crotwell A.M., Dlugokencky E., Petron G., Leuenberger M.
Name of Society : GGMT-2022 (2022)
Name of Proceedings : Abstracts, 99-100
Aircraft monitoring for atmospheric greenhouse gases over Siberia

Presenter : Machida T., Sasakawa M., Arshinov M., Mitin S., Maximov T.
Name of Society : 日本地球惑星科学連合2022年大会 (2022)
Name of Proceedings : -
Increasing trend of summertime CO2 uptake by land biosphere in Northern Eurasia for 2002-2017

Presenter : Shirai T., Ishizawa M., Sasakawa M., Ito A., Machida T., Maksyutov S.
Name of Society : The 27th Symposium on Atmospheric Chemistry (2022)
Name of Proceedings : Book of Abstracts, O1-05
Evaluation of a revised global high-resolution inverse model with CO2 observations over Siberia.

Presenter : Maksyutov S., Sasakawa M., Machida T., Oda T., Zeng J., Matsunaga T., Kaiser J.W., Arshinov M., Belan B., Dlugokencky E.
Name of Society : Japan Geoscience Union Meeting 2021 (2021)
Name of Proceedings : -
Changes in the atmospheric CO2/CH4 variability in the East Asian outflow region caused by plummet of fossil fuel-derived CO2 in China due to COVID-19 outbreak

Presenter : Tohjima Y., Niwa Y., Mukai H., Sasakawa M., Machida T., Nakaoka S., Patra P. K.
Name of Society : Japan Geoscience Union Meeting 2021 (2021)
Name of Proceedings : -, ACG34-03
Top-down estimation of surface terrestrial CO2 flux in Northern Eurasia

Presenter : Shirai T., Misa I., Sasakawa M., Ito A., Machida T., Maksyutov S.
Name of Society : JpGU-AGU Joint Meeting 2020 (2020)
Name of Proceedings : -
Natural and anthropogenic methane emissions in West Siberia estimated using a wetland inventory, GOSAT and a regional tower network

Presenter : Maksyutov S., Sasakawa M., Janardanan achari R., Wang F., Tsuruta A., Terentieva I., Sabrekov A., Glagolev M., Machida T., Arshinov M., Davydov D., Krasnov O., Belan B., Dlugokencky E., Lavric J.V., Ito A., Janssens-Maenhout G., Kaiser J., Yoshida Y., Matsunaga T.
Name of Society : 22nd EGU General Assembly (2020)
Name of Proceedings : -
Assessment of CH4 sources in the Arctic using regional atmospheric measurements and their link to surface emissions

Presenter : Wittig S., Berchet A., Paris Jean-Daniel., Arshinov M., Machida T., Sasakawa M., Worthy D., Pison I.
Name of Society : EGU General Assembly 2020 (2020)
Name of Proceedings : -
Inverse modeling of anthropogenic methane emissions based on ground-based monitoring and GOSAT satellite retrievals

Presenter : Maksyutov S., Tsuruta A., Janardanan achari R., Ito A., KAISER J., Maenhout G.J., Dlugokencky E., Sasakawa M., Machida T., Yoshida Y., Matsunaga T.
Name of Society : 8th International Symposium on Non-CO2 Greenhouse Gases (NCGG8) (2019)
Name of Proceedings : -
GLOBAL HIGH SPATIAL RESOLUTION METHANE ATMOSPHERIC INVERSE MODEL NIES-TMFLEXPART- VAR

Presenter : Tsuruta A., Maksyutov S., Janardanan achari R., Ito A., KAISER J., Maenhout G.J., Dlugokencky E., Sasakawa M., Machida T., Matsunaga T.
Name of Society : 8th International Symposium on Non-CO2 Greenhouse Gases (NCGG8) (2019)
Name of Proceedings : -
Estimating regional anthropogenic methane emissions with GOSAT satellite retrievals and ground-based observations

Presenter : Maksyutov S., Tsuruta A., Janardanan achari R., Wang F., Ito A., Sasakawa M., Machida T., Morino I., Yoshida Y., kaiser J., Janssens-Maenhout G., Dlugokencky E., Matsunaga T.
Name of Society : Japan Geoscience Union Meeting 2019 (2019)
Name of Proceedings : -
Inversion estimates of regional methane emissions and its trends in 2010-2017 by a global high-resolution model

Presenter : Wang F., Maksyutov S., Tsuruta A., Janardanan achari R., Ito A., Sasakawa M., Morino I., Yoshida Y., Kaiser J.W., Janssens-Maenhout G.G.A., Dlugokencky E.J., Matsunaga T.
Name of Society : American Geophysical Union Fall Meeting 2019 (2019)
Name of Proceedings : -
Methane emissions in the Arctic and sub-Arctic from a Bayesian atmospheric inversion

Presenter : Thompson R., Stohl A., Myhre C.L., Sasakawa M., Machida T., Aalto T., Dlugokencky E., Worthy D.
Name of Society : European Geosciences Union General Assembly 2015 (2015)
Name of Proceedings : Geophysical Research Abstracts, 17
Isolating wetland CH4 emissions using the additional constraints of 13CH4, and C2H6 in a inverse modeling framework

Presenter : Ramirez T.G.N., Marshall J., Houweling S., Dlugokencky E.J., Worthy D.E.J., Vaughn B., Simpson I., White J., Brand W.A., Sasakawa M., Nichol S., Ramonet M., Tyler S.C., Hueber J., Helmig D., Read K., Punjabi S., Gatti L.V., Krummel P., Heimann M.
Name of Society : European Geosciences Union General Assembly 2015 (2015)
Name of Proceedings : Geophysical Research Abstracts, 17
Long-term Variations of Atmospheric CH4 Concentration over Siberia Derived from Aircraft Observation

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A., Krasnov O., Patra P., Ishijima K.
Name of Society : 2015 AGU Fall Meeting (2015)
Name of Proceedings : Abstracts
Estimation of methane fluxes in the high northern latitudes from a Bayesian atmospheric inversion

Presenter : Thompson R., Stohl A., Myhre C.L., Sasakawa M., Machida T., Aalto T., Dlugokencky E., Worthy D.
Name of Society : 2015 AGU Fall Meeting (2015)
Name of Proceedings : Abstracts
Full Spectral Resolution Data Generation from the Cross-track Infrared Sounder on S-NPP at NOAA and its Use to Investigate Uncertainty in Methane Absorption Band Near 7.66 um

Presenter : Xiong X., Peischi J., Ryerson T., Sasakawa M., Han Y., Chen Y., Wang L., Tremblay D., Jin X., Zhou L., Liu Q., Weng F., Machida T.
Name of Society : 2015 AGU Fall Meeing (2015)
Name of Proceedings : Abstracts
Aircraft observation of atmospheric greenhouse gases over Siberia

Presenter : Machida T., Sasakawa M., Vinnichenko, N., Arshinov, M., Belan, B., Fedoseev, N., Mitin, S., Matsueda, H., Sawa, Y., Niwa, Y., Tsuboi, K., Katsumata K., Murayama, S., Morimoto, S., Aoki, S.
Name of Society : Russia/Japan Joint Workshop on Environmental Investigations in West Siberia and the Arctic using a synergy of Russian Airplane-Laboratory and Japanese Satellites (2015)
Long-term variations of atmospheric CH4 concentration over Siberia derived from aircraft and tower measurements

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A., Krasnov O., Fedoseev N., Nesterova M., Galanin A., Patra P., Ishijima K.
Name of Society : 7th International Symposium on Non-Co2 Greenhouse Gases (NCGG7) (2014)
Name of Proceedings : Abstracts
Continuous methane measurement using 9-tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T., Tsuda N., Suto H., Arshinov M., Davydov D., Fofonov A., Krasnov O., Saeki T., Koyama Y., Maksyutov S.
Name of Society : Jpn.Geosci.Union Meet.2010 (2010)
Name of Proceedings : Abstracts
Decadal Trends and Satellite Validation of XCO2 and XCH4 over Western Siberia Using Constructed Vertical Profiles

Presenter : Qin Q., Sasakawa M., Machida T., Machida T., Taguchi T., Nogovitcyn A.
Name of Society : JpGU-AGU Joint Meeting 2026 (2026)
Name of Proceedings : Abstracts, ACG63:P01
Urban CO2 simulations for the Greater Tokyo Area based on high-resolution modeling and comparison with tower observation network

Presenter : Yang Z., Terao Y., Lauvaux T., Abdallah C, Oda T., Nishihashi M., Saito M., Ishidoya S., Sugawara H., Machida T., Sasakawa M., Tohjima Y.
Name of Society : The 21st International Workshop on Greenhouse Gas Measurements from Space (IWGGMS-21) (2025)
Name of Proceedings : Abstracts
Examination of anthropogenic CO2 emission inventories using ground-based observations and regional model simulations over the Tokyo Megacity

Presenter : Yang Z., Terao Y., Lauvaux T., Abdallah C., Oda T., Nishihashi M., Saito M., Ishidoya S., Sugawara H., Machida T., Sasakawa M., Tohjima Y.
Name of Society : Japan Geoscience Union Meeting 2025 (2025)
Name of Proceedings : Abstracts
Emission estimation of CO2 over major cities of Japan using NICAM and WRF-GHG

Presenter : BISHT J., Niwa Y., Nakaoka S., Terao Y., Sasakawa M., Tanimoto H., Machida T.
Name of Society : The 2025 Autumn Meeting of the Meteorological Society of Japan (2025)
Name of Proceedings : 2025 年度秋季大会講演予稿集, P(359):590
Decadal variations in vertical profiles of atmospheric carbon dioxide estimated from a combination of tower, aircraft, and satellite measurements in West Siberia

Presenter : Qin Q., Sasakawa M., Machida T., Taguchi T., Nogovitcyn A.
Name of Society : 日本地球惑星科学連合2025年大会 (2025)
Name of Proceedings : -
Fundamental environment for greenhouse gas monitoring at the National Institute for Environmental Studies

Presenter : Sasakawa M., Machida T.
Name of Society : 22nd WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Tracers Measurement Techniques (GGMT-2024) (2024)
Name of Proceedings : -
Understanding the impact of high-temperature events on carbon balance in northern mid-to-high latitude regions

Presenter : Taguchi T., Kondo M., Ichii K., Sasakawa M.
Name of Society : 11th International Carbon Dioxide Conference (2024)
Name of Proceedings : -
Assessing the Long-Range Transport of Persistent Organic Pollutants and Chemical Reactions of Heavy Metals in Aerosols over Hateruma Island, Japan

Presenter : Ito L., Kawakami M., Sasakawa M., Takazawa Y., Takahashi Y., Tokai A.
Name of Society : AGU24 (2024)
Name of Proceedings : -
Observation activities for atmospheric greenhouse gases by CONTRAIL and other platforms by NIES and collaborators

Presenter : Machida T., Niwa Y., Umezawa T., Tsuboi K., Ishijima K., Fujita R., Matsueda H., Sasakawa M., Terao Y., Tohjima Y., Nara H., Saito T., Nakaoka S., Takao S., Aramaki T., Takahashi Y., Hirata R., Mueller A., Srivastava P., Morino I., Ohyama H., Frey M., Noda H., Mukai H., Shirai T., Tanimoto H.
Name of Society : WMO International Greenhouse Gas Monitoring Symposium (2023)
Name of Proceedings : -
Measurements of stable carbon isotope ratio of methane at Hateruma Station, Japan

Presenter : Umezawa T., Terao Y., Tohjima Y., Saito T., Sasakawa M., Mukai H.
Name of Society : The 21st expert meeting on Greenhouse Gas Measurement Techniques (WMO GAW GGMT-2022) (2022)
Name of Proceedings : Abstracts
Assessment of the stability and relationships between the NIES-09, SIO-X12, and WMO-X2019 CO2 scales

Presenter : Crotwell A.M., Keeling R.F., Sasakawa M., Walker S., Hall B.D.
Name of Society : METROLOGY FOR CLIMATE ACTION (2022)
Name of Proceedings : -
Evaluation of strategies for assessing CO2 inter‐laboratory offsets

Presenter : Jordan A., Levin I., Hammer S., Yver C., Ramonet M., Langenfelds R. L., Sasakawa M., Crotwell A. M., Dlugokencky E., Scheeren B., Chen H., Rauh M.
Name of Society : METROLOGY FOR CLIMATE ACTION (2022)
Name of Proceedings : -
WCC and QA/SAC activities and GHG observation by JMA

Presenter : Tohjima Y., Machida T., Terao Y., Sasakawa M., Takatsuji S., Kameoka Y., Kinoshita A., Saito A., Saito K., Ushio N., Yukita K., Yoshida M., Fujiwara S., Iwaki M., Fukuda Y., Sawa Y., Tsuboi K., Ishijima K., Murayama S.
Name of Society : The 21st expert meeting on Greenhouse Gas Measurement Techniques (2022)
Name of Proceedings : Abstracts, 63
Inverse modeling of the carbon sink in the northern boreal regions and comparison with bottom-up data

Presenter : Maksyutov S., Oda T., Zeng J., Sasakawa M., Machida T., Arshinov M., Matsunaga T.
Name of Society : Japan Geoscience Union Meeting 2022 (2022)
Name of Proceedings : -
Recovery of CO2 emissions from China after COVID-19 lockdown estimated from the atmospheric observation at Yaeyama Islands

Presenter : Tohjima Y., Niwa Y., Mukai H., Sasakawa M., Machida T., Patra P. K., Tsuboi K., Saito K.
Name of Society : Japan Geoscience Union Meeting 2022 (2022)
Name of Proceedings : -
Long term trend of summertime CO2 uptake by land biosphere in Northern Eurasia

Presenter : Shirai T., Ishizawa M., Sasakawa M., Ito A., Machida T., Maksyutov S.
Name of Society : Japan Geoscience Union Meeting 2022 (2022)
Name of Proceedings : -
Near-real-time estimation of fossil fuel CO2 emissions from China based on atmospheric observations at remote islands in Japan

Presenter : Tohjima Y., Niwa Y., Patra P.K., Mukai H., Machida T., Sasakawa M., Tsuboi K., Saito K., Ito A.
Name of Society : AGU Fall Meeting 2022 (2022)
Name of Proceedings : -
Top-down estimate of the terrestrial carbon balance for northern boreal regions suggests larger carbon sink in Siberia

Presenter : Maksyutov S., Oda T., Zeng J., Kaiser J.W., Sasakawa M., Machida T., Arshinov M., Belan B.D., Yoshida Y., Matsunaga T.
Name of Society : AGU Fall Meeting 2021 (2021)
Name of Proceedings : -
Recent stagnation of CH4 emission growth from East Asia based on the analysis of synoptic variations of atmospheric CH4 and CO2 observed at Hateruma Island

Presenter : Tohjima Y., Zeng J., Ito A., Naveen C., Niwa Y., Mukai H., Shirai T., Sasakawa M., Patra P. K., Machida T.
Name of Society : JpGU-AGU Joint Meeting 2020 (2020)
Name of Proceedings : -, AAS07-P02
GHGs data comparison between NIES observation network (aircrafts, Ships and stations) in the Asian Pacific area and GOSAT

Presenter : Nomura S., Mukai H., Terao Y., Machida T., Sasakawa M., Morino I.
Name of Society : The 20th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases,and Related Measurement Techniques (GGMT2019) (2019)
Name of Proceedings : Abstract, 94
Working standard gas saving system for in situ CO2 and CH4 measurements and calculation method for concentrations and their uncertainty

Presenter : Sasakawa M., Tsuda N., Machida T., Arshinov M., Davydov D., Fofonov A.
Name of Society : GGMT2019 (2019)
Name of Proceedings : Abstracts
Working standard gas saving system for in-situ CO2 and CH4 measurements and calculation method for concentrations and uncertainty

Presenter : Sasakawa M., Tsuda N., Machida T., Arshinov M., Davydov D., Fofonov A.
Name of Society : 8th International Symposium on Non-CO2 Greenhouse Gases (2019)
Name of Proceedings : Abstracts
Comparing national methane emissions inventories with estimates by the global high-resolution inverse model

Presenter : Wang F., Tsuruta A., Maksyutov S., Janardanan achari R., Ito A., Sasakawa M., Machida T., Morino I., Yoshida Y., Kaiser J.W., Janssens-Maenhout G., Dlugokencky E., Matsunaga T.
Name of Society : The 15th International Workshop on Greenhouse Gas Measurements from Space (2019)
Name of Proceedings : Abstract Collection, 103
Global inverse analysis of CH4 fluxes using NICAM-TM 4D-Var

Presenter : Niwa Y., Ito A., Machida T., Sasakawa M., Tohjima Y., Terao Y., Umezawa T., Morimoto S., Aoki S., Sawa Y., Tsuboi K., Matsueda H., Dlugokencky E., Harth C., Krummel P. B., Langenfelds R. L., Loh Z. M., Mühle J., O’Doherty S., Prinn R. G., Ramonet M., Salameh P., Sweeney C., Weiss R., Young D., Castaldi S., Noce S., Saunois M., Stavert A. R.
Name of Society : 日本地球惑星科学連合2019年大会 (2019)
Name of Proceedings : -
Top-down estimates of methane emissions in Russia using regional tower network observations

Presenter : Sasakawa M., Wang F., Tsuruta A., Maksyutov S., Janardanan achari R., Ito A., Janssens-Maenhout G., Dlugokencky E.J., Arshinov M., Krasnov O., Kaiser J.W., Matsunaga T., Machida T.
Name of Society : AGU Fall Meeting2019 (2019)
Name of Proceedings : Abstracts
Working standard gas saving system for in-situ CO2 and CH4 measurements and calculation method for concentrations and uncertainty

Presenter : Sasakawa M., Tsuda N., Machida T., Arshinov M., Denis D., Fofonov A.
Name of Society : Japan Geoscience Union Meeting 2018 (2018)
Name of Proceedings : -
Fonovaya Observatory for comprehensive atmospheric monitoring in West Siberia:current status and future needs

Presenter : Belan B.D. , Arshinov M., Davydov D., Fofonov A., Kozlov A., Machida T., Sasakawa M., Paris J.D.
Name of Society : EGU General Assembly 2018 (2018)
Name of Proceedings : Geophysical Research Abstracts, 20(6183-1)
Three-dimensional concentration fields of methane simulated with a Lagrangian model nudged with observation data

Presenter : Zwaaftink C.G., Henne S., Thompson R., Machida T., Paris J.D., Sasakawa M., Segers A., Sweeney C., Stohl A.
Name of Society : EGU General Assembly 2018 (2018)
Name of Proceedings : Geophysical Research Abstracts, 20(13946)
Continuous measurement of CO2 and CH4 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A.
Name of Society : 10th International Carbon Dioxide Conference (2017)
Name of Proceedings : ICDC 10 Abstracts, 99
Continuous measurement of CO2 and CH4 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A.
Name of Society : JpGU-AGU Joint Meeting 2017 (2017)
Name of Proceedings : Abstracts, (AAS11-P05)
Methane budget estimates for northern high latitudes by CarbonTracker Europe-CH4

Presenter : Tsuruta A., Aalto T., Backman L., Laan-Luijkx I.T.V.D., Krol M., Spahni R., Lienert S., Houweling S., Laurila T., Hatakka J., Dlugokencky E., Worthy D., Sasakawa M., Peltola O., Mauranen A., Heiman M., Kozlova L., Crotwell A., Peters W.
Name of Society : The 2nd ICOS Science Conference (2016)
Name of Proceedings : -
Methane budgets in northern latitudes during soil freezing period

Presenter : Aalto T., Kangasaho V., Tsuruta A., Rautiainen K., Backman L., Laan-Luijkx I.T.V.D., Krol M., Spahni R., Lienert S., Houweling S., Laurila T., Juha Hatakka, Worthy D., Sasakawa M., Peltola O., Mauranen A., Heimann M., Kozlova L., Dlugokencky E., Crotwell A., Peters W.
Name of Society : The 2nd ICOS Science Conference (2016)
Name of Proceedings : -
Continuous measurement of CO2 and CH4 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Tsuda N., Katsumata K., Arshinov M., Davydov D., Fofonov A.
Name of Society : 日本地球惑星科学連合2016年大会 (2016)
Name of Proceedings : 同予稿集
Methane fluxes in the high northern latitudes estimated using a Bayesian atmospheric inversion

Presenter : Thompson R., Stohl A., Myhre C. L., Sasakawa M., Machida T., Aalto T., Dlugokencky E., Worthy D., Skorokhod A.
Name of Society : EGU General Assembly 2016 (2016)
Name of Proceedings : Geophysical Research Abstracts, 18(11875)
Changes in CO2 trends observed in the lower troposphere over West Siberia

Presenter : Belan B.D. , Machida T., Sasakawa M., Maksyutov S., Davydov D., Fofonov A., Arshinov M.
Name of Society : EGU General Assembly 2016 (2016)
Name of Proceedings : Geophysical Research Abstracts, 18(11616)
Analysis of atmospheric methane from Siberian tower observation using chemistry transport model

Presenter : Ishijima K., Ishijima K., Sasakawa M., Machida T., Patra P.K., Ito A., Kumar K.R., Saeki T., Morimoto S., Aoki S., Nakazawa T.
Name of Society : GRENE北極気候変動研究事業研究成果報告会 (2016)
Name of Proceedings : 講演予稿集
Continuous measurement of CO2 and CH4 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Ito A., Tsuda N., Arshinov M., Davydov D., Fofonov A.
Name of Society : The 22nd Symposium on Atmospheric Chemistry (2016)
Name of Proceedings : Book of Abstracts, 48
COMPARISON OF CARBON DIOXIDE MIXING RATIOS FROM IN-SITU MEASUREMENTS BY NDIR AND CRDS ANALYZERS AND BOTTLE SAMPLING MEASUREMENTS AT HATERUMA ISLAND

Presenter : Katsumata K., Mukai H., Sasakawa M., Tohjima Y., Machida T., Terao Y.
Name of Society : 18th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Measurement Techniques (GGMT-2015) (2015)
Name of Proceedings : Abstracts
Estimating regional CH4 fluxes using ground-based and space-based observations

Presenter : Kim H., Maksyutov S., Saito M., Ito A., Belikov D., Saeki T., Morino I., Uchino O., Yoshida Y., Sasakawa M., Machida T., Yokota T.
Name of Society : 日本気象学会2015年度春季大会 (2015)
Name of Proceedings : 同予稿集, 236-236
Spatial and Temporal Variability of CO2 and CH4 Concentrations in the Atmospheric Surface Layer over West Siberia

Presenter : Belan B.D., Machida T., Sasakawa M., Davydov D.K. , Fofonov A. V. , Krasnov O.A. , Maksyutov S., Arshinov M.Y.
Name of Society : European Geosciences Union General Assembly 2015 (2015)
Name of Proceedings : Geophysical Research Abstracts, 17
Developing a high-resolution CO2 flux inversion model for global and regional scale studies

Presenter : Maksyutov S., Janardanan R., Oda T., Ito A., Saito M., Kaiser J., Belikov D., Ganshin A., Valsala V., Sasakawa M., Machida T.
Name of Society : 2015 AGU Fall Meeting (2015)
Name of Proceedings : Abstracts
Inverse modeling analysis of regional methane fluxes using GOSAT retrievals in 2010-2012

Presenter : Kim H., Maksyutov S., Belikov D., Ito A., Morino I., Yoshida Y., Yokota T., Sasakawa M., Machida T.
Name of Society : 2015 AGU Fall Meeting (2015)
Name of Proceedings : Abstracts
Long-term variations of atmospheric CH4 concentration over Siberia derived from aircraft and tower observation

Presenter : Sasakawa M., Machida T., Ito A., Tsuda K., Arshinov M., Davydov D., Fofonov A., Krasnov O., Patra P.K., Ishijima K.
Name of Society : 第21回大気化学討論会 (2015)
Name of Proceedings : 第21回大気化学討論会講演要旨集, 88
Effect of Atmospheric CO2 Observations in Asia on the Optimization of Surface CO2 Flux

Presenter : Kim J., Kim H.M., Cho C., Jacobson A., Jacobson A., Sasakawa M., Machida T., Arshinov M., Fedoseev N.
Name of Society : 2014 AGU Fall Meeting (2014)
Name of Proceedings : Abstracts
Continuous measurement of carbon dioxide, methane, and carbon monoxide mole fractions using cavity ring-down spectroscopy at Hateruma Island

Presenter : Katsumata K., Tohjima Y., Sasakawa M., Mukai H.
Name of Society : 17th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Tracers Measurement Techniques (2013)
Name of Proceedings : Abstracts
Continuous measurements of CO2 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Tsuda N., Arshinov M., Davydov D., Fofonov A., Krasnov O., Fedoseev N.
Name of Society : 9th International Carbon Dioxide Conference (2013)
Name of Proceedings : Abstracts
Model resolution comparison for methane simulation in the Arctic region

Presenter : Ishijima K., Patra P.K., Ghosh A., Morimoto S., Machida T., Sasakawa M., Tohjima Y., Ito A., Aoki S., Nakazawa T.
Name of Society : Third International Symposium on the Arctic Research (2013)
Name of Proceedings : Abstracts, 128-128
Observations of atmospheric greenhouse gases from a tower network and aircraft over Siberia

Presenter : Machida T., Sasakawa M., Sawa Y., Matsueda H., Morimoto S., Murayama S., Niwa Y., Tsuboi K., Aoki S.
Name of Society : Third International Symposium on the Arctic Research (2013)
Name of Proceedings : Abstracts, 137-137
Carbon flux estimation for Siberia by inverse modeling constrained by aircraft and tower CO2 measurements

Presenter : Saeki T., Maksyutov S., Sasakawa M., Machida T., Arshinov M., Tans P.P., Conway T.J., Saito M., Valsala V., Oda T., Andres R.J.
Name of Society : AGU Fall Meeting 2012 (2012)
Name of Proceedings : Abstracts
Continuous measurements of CO2 concentration from a tower network (JR-STATION) over Siberia

Presenter : Sasakawa M., Machida T., Tsuda T., Arshinov M., Davydov D., Fofonov A., Krasnov O., Fedoseev N.
Name of Society : 第18回大気化学討論会 (2012)
Name of Proceedings : 第18回大気化学討論会講演要旨集, 86-86
Annual variation of CH4 emissions from forested bogs in West Siberia (2005–2009): a case of high CH4 and precipitation rate in the summer of 2007

Presenter : Sasakawa M., Ito A., Machida T., Tsuda N., Niwa Y., Davydov D., Fofonov A., Arshinov M.
Name of Society : Sixth International Symposium on Non-CO2 Greenhouse Gases (NCGG-6) (2011)
Name of Proceedings : -
Aircraft tower measurements of CO2 concentration in the planetary boundary layer and lower free troposphere over taiga in West Siberia: Long-term records from 2002 to 2010

Presenter : Sasakawa M., Machida T., Tsuda N., Shimoyama K., Arshinov M., Davydov D., Fofonov A., Krasnov O.
Name of Society : 第16回大気化学討論会 (2010)
Name of Proceedings : 同講演要旨集, 71
Annual variation(2005-2009)of methane emissions from wetlands at West Siberia: Anomalous increase induced by high precipitation rate in the summer of 2007

Presenter : Sasakawa M., Ito A., Machida T., Tsuda N., Niwa Y., Arshinov M.
Name of Society : 日本気象学会2010年度秋季大会 (2010)
Name of Proceedings : 同講演予稿集, 406
Continuous measurement of carbon dioxide and methane concentration using 9-tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T., Tsuda N., Suto H., Arshinov M., Davidov D., Fofonov A., Krasnov O., Saeki T., Koyama Y., Maksyutov S.
Name of Society : 8th Int.Carbon Dioxide Conf. (2009)
Name of Proceedings : Abstracts
Continuous measurement of atmospheric methane concentration using 9-tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T.
Name of Society : Jpn.Geosci.Union Meet.2009 (2009)
Name of Proceedings : Abstracts, F119-P009
Continuous measurement of methane concentration using 9-tower network over Siberia

Presenter : Sasakawa M., Shimoyama K., Machida T., Tsuda N., Suto H., Arshinov M., Davydov D., Fofonov A., Krasnov O., Saeki T., Koyama Y., Maksyutov S.
Name of Society : 第15回大気化学討論会 (2009)
Name of Proceedings : 同講演要旨集, 69

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Observation of atmospheric CH4 using aircraft platform

Presenter : Machida T., Sasakawa M., Umezawa T., Sawa Y., Matsueda H., Niwa Y., Tsuboi K., Murayama S., Morimoto S., Aoki S.
Name of Society : InGos International Conference (2015)
Name of Proceedings : Abstracts
Tropospheric methane and carbon dioxide over West Siberia: observation data analysis, surface flux inventories and transport modeling

Presenter : Maksyutov S., Machida T., Sasakawa M., Koyama Y., Saeki T., Shimoyama K., Glagolev M., Kim H., Inoue G., Fedoseev N.
Name of Society : AGU Fall Meeting 2009 (2009)
Name of Proceedings : Abstracts
Validation of a new high-resolution CH4 emission dataset for Russian wetlands

Presenter : Nogovitcyn A., Sasakawa M., Maksyutov S., Machida T., Taguchi T., Qin Q.
Name of Society : The Eighth International Symposium on Arctic Research (2025)
Name of Proceedings : ISAR8_program, R1-O-03

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SASAKAWA Motoki

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