Atmospheric trace gas data from the CONTRAIL flask air sampling over the Pacific Ocean

Click Here to Download

This data set contains trace gas mole fractions observed over the Pacific Ocean by the flask air sampling of the CONTRAIL (Comprehensive Observation Network for TRace gases by AIrLiner) project. Air samples were collected by the Automatic air Sampling Equipment (ASE) and manually by the Manual air Sampling Equipment (MSE) on board commercial aircraft of Japan Airlines (JAL).


Toshinobu Machida*1 (, Hidekazu Matsueda*2,*3, Yousuke Sawa*2,*4, Yosuke Niwa*1 (, Kazuhiro Tsuboi*2, Kentaro Ishijima**2, Keiichi Katsumata*5,*6, Shohei Murayama*7, Shinji Morimoto*8,*9, Daisuke Goto*10, Shuji Aoki*8,*9, Motoki Sasakawa*1
*1 Earth System Division, National Institute for Environmental Studies (NIES)
*2 Meteorological Research Institute
*3 Dokkyo University
*4 Now at Atmosphere and Ocean Department, Japan Meteorological Agency
*5 Center for Global Environmental Research, National Institute for Environmental Studies (NIES)
*7 National Institute of Advanced Industrial Science and Technology (AIST)
*8 Center for Atmospheric and Oceanic Studies
*9 Graduate School of Science, Tohoku University
*10National Institute of Polar Research (NiPR)
Release date
Temporal coverage
1993/04/23 - 2021/10/25
Data provider
Email: cgerdb_admin(at)
File format
Data volume
2.45 MB
ver.2023.1.0 (Last updated: 2023/07/25)
Related contents
Dataset is part of: Atmospheric trace gas data from the CONTRAIL flask air sampling, DOI:10.17595/20230725.001
Publications using this dataset

Data Set

Atmospheric mole fractions of CO2 and CH4
Observation period
From April 23, 1993 (ongoing)
Measurement method
Air samples were introduced to various analyzers by an automated analysis system. The CO2 mole fraction was measured using a nondispersive infrared gas analyzer (NDIR; LI-6252 or LI-6262, LI-COR) and the CH4 mole fraction was measured using a gas chromatograph (Agilent 5890 or 7890A, Agilent Technologies Inc.) equipped with a flame ionization detector (GC-FID).
Calculation method
The CO2 and CH4 mole fractions in the sample air were calculated by least square fit assuming a quadratic relationship between the responses of analyzers and the mole fractions of four standard gases. The values of standard gases were based on the NIES95 scale for CO2 and the NIES94 scale for CH4.
Aircraft > AIRCRAFT
Atmosphere > Atmospheric Chemistry > Carbon and Hydrocarbon Compounds > Carbon Dioxide
Atmosphere > Atmospheric Chemistry > Carbon and Hydrocarbon Compounds > Methane
[Free keywords]
Carbon Dioxide, CO2, Methane, CH4, Aircraft, B777-200ER, B777-300ER
Update history
Data are extended to the end of 2021. ver.2023.1.0.
Motoki Sasakawa joined the creators. ver.2021.1.0.
Data of CO2 and CH4 are released. ver.2019.1.0.


The observations of the CONTRAIL project are conducted under great support from Japan Airlines, JAMCO and the JAL Foundation. The CONTRAIL project has been financially supported by the Global Environmental Research Coordination System from Ministry of the Environment of Japan (MOE0653, MOE1151, MOE1652, MOE2151). In addition, this Eurasian observation is supported by the GRENE Arctic Climate Change Research Project and Arctic Challenge for Sustainability project I & II (ArCS & ArCS II) of the Ministry of Education, Culture, Sports, Science and Technology, Japan.


Matsueda, H., T. Machida, Y. Sawa, Y. Niwa (2015), Long-term change of CO2 latitudinal distribution in the upper troposphere, Geophys. Res. Lett., 42, doi:10.1002/2014GL062768.
Machida, T., H. Matsueda, Y. Sawa, Y. Nakagawa, K. Hirotani, N. Kondo, K. Goto, N. Nakazawa, K. Ishikawa and T. Ogawa (2008), Worldwide measurements of atmospheric CO2 and other trace gas species using commercial airlines, J. Atmos. Oceanic Technol., 25(10), 1744-1754, doi:10.1175/2008JTECHA1082.1.
Matsueda, H., T. Machida, Y. Sawa, Y. Nakagawa, K. Hirotani, H. Ikeda, N. Kondo, and K. Goto (2008), Evaluation of atmospheric CO2 measurements from new flask air sampling of JAL airliner observations, Pap. Meteorolo. Geophys., 59, 1-17, doi:10.2467/mripapers.59.1.
Umezawa, T., T. Machida, K. Ishijima, H. Matsueda, Y. Sawa, P. K. Patra, S. Aoki, and T. Nakazawa (2012), Carbon and hydrogen isotopic ratios of atmospheric methane in the upper troposphere over the Western Pacific, Atmos. Chem. Phys., 12, 8095-8113, doi:10.5194/acp-12-8095-2012.
Matsueda, H., H. Y. Inoue, and M. Ishii (2002), Aircraft observation of carbon dioxide at 8-13 km altitude over the western Pacific from 1993 to 1999, Tellus, 54B,1-21, doi:10.3402/tellusb.v54i1.16645.

Terms and Conditions of Use*

*By accessing or using the Service you agree to follow these Terms. If you disagree with any part of the Terms, you may not access the Service.
The author of this data set (hereafter "Author") agrees to the use of this data set by person(s) wishing to use the data (hereafter "User") as stipulated in the Terms and Conditions below.

Scope of consent
The User may re-distribute the data to third party without any change or transformation of the data, and may publish new intellectual products (hereafter "Products") based on this data set.
Conditions for distribution
The User shall not accept any compensation for the re-distribution of the data of this data set to a third party.
In the event that the User re-distributes the data of this data set to a third party, the same Terms and Conditions apply also to the re-distributed data set.
When the User re-distributes the data of this data set to a third party, the User is obliged to inform the third party about the URL of the original data set, the Terms and Conditions of Use, and the fact that the data set is continuously updated by the Author.
Use of the latest version
Unless special reason exists, the User shall use the latest version of this data set.
Citation policy
When publishing any Products based on the present data set, it must be clearly stated that the present data set was used.
However, the Author may request the User to delete the citation from the Product. In that case, the User shall comply with the request within reasonable extent.
If these data have an important part in the User's Product, the User must contact the Author concerning co-authorship before publication. Citing this data set as described below and acknowledging the Author are enough when these data play a minor role in the User's Product (e.g., global analyses such as inverse modeling).
Citation format
When this data set is referred to in publications, it should be cited in the following format.
Machida, T., H. Matsueda, Y. Sawa, Y. Niwa, and M. Sasakawa (2019), Atmospheric trace gas data from the CONTRAIL flask air sampling over the Pacific Ocean, ver.x.x.x*1, Center for Global Environmental Research, NIES, DOI:10.17595/20190828.001. (Reference date*2: YYYY/MM/DD)
*1 The version number is indicated in the name of each data file.
*2 As the reference date, please indicate the date you downloaded the files.
When generally referring to the flask sampling data of CONTRAIL, please also cite Matsueda et al. (2015) and Machida et al. (2008). Furthermore, the User is encouraged to cite relevant paper(s) listed at above References (see for more references). Specifically, the User who used the CH4 data is recommended to refer Umezawa et al. (2012).
Utilization reporting
Re-distribution of the data or release of Products derived from the data set, shall be reported to the Data Provider without delay.
Error reporting
Any error in the data set, or the suspicion thereof, should be immediately reported to the Data Provider.
The Author and the Data Provider shall not have any liability or responsibility whatsoever for any damage that may arise from the use of this data set, and the User must not imply that any guarantee is provided by the Author or the Data Provider. Any injury or loss arising from the use of this data set is solely the responsibility of the User.

Advisory Service

Advisory service
If you need scientific advice or expert opinion regarding the contents or scientific validity of this data set or Products derived from it, we can provide an advisory service based on an individual contract, different from the above one.
Depending on the extent of the help required, we can offer collaboration and/or supervision of the work based on the present data set. If you want to use our advisory service, contact the Data Provider.