Data Policy
GAW Data Policy
"For Scientific purposes, access to these data is unlimited and provided without charge.
By their use you accept that an offer of co-authorship will be made through personal contact with the data providers
or owners whenever substantial use is made of their data.
In all cases, an acknowledgement must be made to the data providers or owners and to the data centre when these data are used within a publication."
Version
2025-01-01-0110 (Last updated: 2024-12-25)File
This data set is submitted by TU.
In line with the GAW Data Policy, users should contact the contributors of all data of interest and propose co-authorship or acknowledgement.
Organization
| NO | 70 |
|---|---|
| Acronym | TU |
| Name | Tohoku University |
| Address 1 | Center for Atmospheric and Oceanic Studies |
| Address 2 | 6-3 Aoba, Aramaki, Aoba-ku |
| Address 3 | Sendai 980-8578 |
| Country/Territory | Japan |
| Website | http://tgr.gp.tohoku.ac.jp |
Contact(s)
| Name | Shinji Morimoto |
|---|---|
| Prefix | Prof. |
| mon@tohoku.ac.jp | |
| Organization No | 70 |
| Organization acronym | TU |
| Organization name | Tohoku University |
| Organization country/territory | Japan |
| Address 1 | |
| Address 2 | |
| Address 3 | Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578 |
| Country/territory | Japan |
| Tel | +81-22-795-5780 |
| Fax | +81-22-795-5797 |
| Last updated date | 2024-10-04 |
| Name | Kentaro ISHIJIMA |
|---|---|
| Prefix | Dr. |
| ishijima@mri-jma.go.jp | |
| Organization No | 48 |
| Organization acronym | MRI |
| Organization name | Meteorological Research Institute |
| Organization country/territory | Japan |
| Address 1 | |
| Address 2 | Department of Climate and Geochemistry Research |
| Address 3 | 1-1 Nagamine, Tsukuba, Ibaraki 305-0052 |
| Country/territory | Japan |
| Tel | +81-29-853-8725 |
| Fax | |
| Last updated date | 2025-01-16 |
| Unknown | |
| UTC | |
| ppb | |
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9999-12-31 00:00:00 - 9999-12-31 23:59:59: Unknown(Gas chromatography (ECD)) |
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| event | |
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The N2O concentration values of our working standard gases were 257.75, 306.05 and 350.87 ppb for the old GC system and 121.66, 283.95, 321.08 and 370.17 ppb for the new GC system, which were calibrated against our gravimetrically prepared primary standard gases. The calibration of the working standard gases against our gravimetrically prepared primary standard gases was made almost bi-yearly, and no significant concentration differences between the working and primary standards were found. The concentration of each sample was determined from its chromatogram area, assuming a quadratic relationship between the concentrations of the working standard gases and their chromatogram areas.Analyses of 3 working gases were performed every 3-6 samples analyses, and chromatogram areas of the working gases at the time of each sample analysis were calculated by temporally-interpolating areas of working gases. Measurement precision was ±1.0 for the old GC system, and ±0.2 ppb for new GC system. |
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[Hourly] [Daily] [Monthly] |
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| Temporarily suspended | |
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On cruises that took around 30-day round trip between Japan and North America, covering a region 35N to 55N in the North Pacific, about 20 air samples were collected at every 10-degree between 150E and 130W. On the other hand, 30-36 air samples were collected at every 5-degree between 33N and 40S during each of the 40-day round cruise between Japan and Australia (or New Zealand after December 1999). The N2O concentrations of the air samples were determined at Tohoku University against our air-base N2O working standard gases, using a gas chromatograph (GC) equipped with an electron capture detector (ECD). Two sets of GC system were used for this study. The old GC, GC-14A (Shimazu, Japan), was used for the period of October 1991 to December 2002 but was replaced by a new one, Agilent 6890 (Agilent Technologies, USA), in September 2002. A mixture of highly pure Ar (95%) and CH4 (5%) was used as a carrier gas for both GC systems. To obtain sufficiently large chromatogram area of N2O, a 10 mL sample loop was used. The sample air was dried by passing it through a H2O trap cooled to -80 degree-C before introduction into the sample loop. The sample air introduced into the loop was kept for 30 s to equalize its temperature to that of the oven and then led to the columns. Both GC systems have one precut and two main Porapak columns, and CO2 and SF6 contained in the samples were completely separated from N2O by these columns, so that the respective components of CO2,N2O and SF6 arrive at the ECD in 5.3, 6.9 and 8.7 minutes after introducing the sample air into the precut column. It took about 12 minutes to analyse one air sample on both GC systems. The air intake was installed on a windward side of the bridge of the ship to prevent ship contamination, and each air sample was pressurized into a 550 mL Pyrex glass flask with Nitrile O-ring seal to about 0.12 MPa by using an electric diaphragm pump. Before air sampling, all glass flasks werewashed by using an ultrasonic cleaner and then evacuated to 1.3 Pa at 100 degree-C for 6 hours. |
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Wind direction: Wind speed: Relative humidity: Precipitation amount: Air pressure: Air temperature: Dew point temperature: Sea water temperature: Sea surface water temperature: Sea water salinity: Sea surface water salinity: |
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Meteorological data may remain as first provided, even when greenhouse gas data are updated. |
No DOI available
Related information
GAW Data Policy
"For Scientific purposes, access to these data is unlimited and provided without charge.
By their use you accept that an offer of co-authorship will be made through personal contact with the data providers
or owners whenever substantial use is made of their data.
In all cases, an acknowledgement must be made to the data providers or owners and to the data centre when these data are used within a publication."
Citation format
This format is an example of the WDCGG standard citation.
Please follow the citation format which the data providers or owners indicate.
Please follow the citation format which the data providers or owners indicate.
Shinji Morimoto (TU),
Kentaro ISHIJIMA (MRI),
Atmospheric N2O
by Northern and western Pacific, Tohoku University,
dataset published as N2O_NWP8036_
ship-flask_TU_data1 at WDCGG,
ver. 2025-01-01-0110 (Reference date*: YYYY/MM/DD)
* As the reference date, please indicate the date you downloaded the files.
* As the reference date, please indicate the date you downloaded the files.
Reference(s)
| 1 | Ishijima, K., T. Nakazawa and S. Aoki, Variations of atmospheric nitrous oxide concentration in the northern and western Pacific, Tellus B, 61, 2, 408-415, 2009. |
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