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The present data set is time series data of atmospheric O2/N2 ratios and CO2 mole fractions from air samples collected at a monitoring station on Minamitorishima, Japan. Air samples, drawn by a pump from an intake placed on a tower at a height of 20 m above ground level, are forced into Pyrex glass flasks. The collected air samples are sent back to a laboratory in NIES, where O2/N2 ratios and CO2 mole fractions are measured.
Description
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Creator
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Release date
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2023/08/30
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Temporal coverage
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2011/09/21 - 2022/04/05
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NIES
Email: cgerdb_admin(at)nies.go.jp |
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DOI
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File format
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Data volume
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16.6 KB
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Latest version
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Ver 1.0 (Last updated: 2023/08/30)
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Language
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English
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orcid.org/0000-0003-2153-6376Data Set
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Parameters
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O2/N2 ratio, CO2 mole fraction
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Precision
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5 per meg
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Observation period
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From Sep. 21, 2011(ongoing)
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Location
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24.2883°N, 153.9833°E
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Altitude
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Elevation: 7.1 m;
Sampling height: 20 m above ground; Altitude: 27 m |
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Measurement method
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From an air intake placed on a steel monitoring tower 20 m above ground (27 m above sea level), outside air is drawn in through a stainless tube to a ground-based observation room using a diaphragm pump. After passing through a cold trap(−40℃) to reduce water vapor, the air samples are forced into Pyrex glass flasks equipped with two glass stopcocks sealed by Viton O-rings to a pressure of 0.2 MPa (0.1 MPa above the ambient pressure). The collected air samples are sent back to a laboratory in NIES, where O2/N2 ratios and CO2 mole fractions are measured by a gas chromatograph equipped with a thermal conductivity detector (GC/TCD) and a non-dispersive infrared analyzer (NDIR), respectively.
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Calculation method
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The O2/N2 ratios of the air samples are reported as relative deviations from a reference gas according to δ(O2/N2)={(O2/N2)sample/(O2/N2)reference-1}x106, which are express in per meg units. The reported δ(O2/N2) values and CO2 mole fractions are determined against the NIES original O2/N2 scale and NIES 09 CO2 scale.
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Keywords
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[Free keywords]
Atmospheric oxygen
[GCMD_Platform]Ground station
[GCMD_Science]Global carbon cycle
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Update history
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[2023/8/30]
The data from 2011 to 2022 have been compiled in NASA Ames Format 1001. Ver.1.0.
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Note
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Discrete flask sample
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Contributors
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Researcher
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Kazuhiro Tsuboi
Meteorological Research Institute |
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Data Manager
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Data Manager
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References Information
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References
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Tohjima, Y. (2000), Method for measuring changes in the atmospheric O2/N2 ratio by a gas chromatograph equipped with a thermal conductivity detector, J. Geophys. Res., 105, 14,575–14,584, doi:10.1029/2000JD900057.
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Grant Agency
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Ministry of the Environment
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Grant Number
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E1451
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Terms and Conditions of Use*
*By accessing or using the Service you agree to be bound by these Terms. If you disagree with any part of the terms then you may not access the Service.
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License
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Citation format
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When this data set is referred to in publications, it should, as a general rule, be made in the following format.
Tohjima et al. (2023), O2/N2 ratios and CO2 mole fractions of air samples collected on Minamitorishima, Ver.x.x *1, NIES, DOI:10.17595/20230830.003. (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. |
Advisory Service
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Advisory service
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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. |