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
2025-01-01-0002 (Last updated: 2024-12-25)File
This data set is submitted by NOAA.
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 | 2 |
|---|---|
| Acronym | NOAA |
| Name | Global Monitoring Laboratory, NOAA |
| Address 1 | NOAA/ESRL |
| Address 2 | R/GML1 |
| Address 3 | 325 Broadway Boulder, CO 80305-3328 |
| Country/Territory | United States of America |
| Website | https://gml.noaa.gov/ |
Contact(s)
| Name | Xin Lan |
|---|---|
| Prefix | |
| xin.lan@noaa.gov | |
| Organization No | 2 |
| Organization acronym | NOAA |
| Organization name | Global Monitoring Laboratory, NOAA |
| Organization country/territory | United States of America |
| Address 1 | NOAA GML |
| Address 2 | 325 Broadway R/GML-1 |
| Address 3 | Boulder, CO 80305-3328 |
| Country/territory | United States of America |
| Tel | |
| Fax | |
| Last updated date | 2025-04-28 |
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| Background observation | |||||||
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9999-12-31 00:00:00 - 9999-12-31 23:59:59: WMO N2O X2006A |
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1997-08-04 08:00:00 - 2019-06-02 10:00:00: Unknown(Gas chromatography (ECD)) 2019-06-17 10:24:00 - 2023-12-31 09:40:00: Unknown(TILDAS) |
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Value_unc is estimated uncertainty of the reported measurement value. For measurements using gas chromatography, aliquots of gas from ambient air samples and a cylinder of reference gas are alternately injected into a gas chromatograph (GC) with a sampling valve. Nitrous oxide (N2O) is separated from other sample components using packed columns and detected with an electron capture detector (ECD). The response of the ECD to N2O is calibrated off-line about monthly relative to the reference with a suite of gas standards. Each aliquot of sample is measured relative to the same reference, and N2O values are calculated from the response function. In August, 2019, we replaced the GC/ECD method for N2O measurement with a Tunable Infrared Laser Direct Absorption Spectroscopy (TILDAS) method. The analyzer is calibrated off-line once per month With a suite of standards relative to a dry, natural air, reference in a high-pressure cylinder. All air samples are measured relative the same reference, and N2O values in measured samples are calculated based on their ratio to the reference. Repeatability of the analyzer, based on repeated analysis of air from a high-pressure cylinder, ranges from ~0.2 to 0.4 ppb for the GC to 0.01 to 0.02 ppb for the TILDAS analyzer (1 sigma). The scale propagation uncertainty is estimated to be 0.12 ppb, based on the reproducibility determined for scale propagation in our calibration laboratory. Long-term reproducibility is estimated to be +/- 0.1 ppb based on repeated measurements of air from a high-pressure cylinder, or the long-term variability in the differences between measurements of test flasks on the flask-air analysis system and separate measurements of the test gas used to fill the test flasks. These three components of uncertainty are added in quadrature to calculate the measurement uncertainty. |
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[Hourly] [Daily] [Monthly] Monthly means are produced for each site by first averaging all valid measurement results in the event file with a unique sample date and time. Values are then extracted at weekly intervals from a smooth curve (Thoning et al., 1989) fitted to the averaged data and these weekly values are averaged for each month to give the monthly means recorded in the files. Flagged data are excluded from the curve fitting process. Some sites are excluded from the monthly mean directory because sparse data or a short record does not allow a reasonable curve fit. Also, if there are 3 or more consecutive months without data, monthly means are not calculated for these months. |
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| This is the NOAA 3-character quality control flag. Column 1 is the REJECTION flag. An alphanumeric other than a period (.) in the FIRST column indicates a sample with obvious problems during collection or analysis. This measurement should not be interpreted. Column 2 is the SELECTION flag. An alphanumeric other than a period (.) in the SECOND column indicates a sample that is likely valid but does not meet selection criteria determined by the goals of a particular investigation. For example, it might not have been obtained during 'background' conditions. Column 3 is the INFORMATION flag. An alphanumeric other than a period (.) in the THIRD column provides additional information about the collection or analysis of the sample. A P in the 3rd column of the QC flag indicates the measurement result is preliminary and has not yet been carefully examined by the PI. The P flag is removed once the quality of the measurement has been determined. | |||||||
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Valid (background): ... Valid (background): ..? Valid: .?? Invalid: ??? |
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| Operational/Reporting | |||||||
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Atmospheric N2O Dry Air Mole Fractions from the NOAA GML Carbon Cycle Cooperative Global Air Sampling Network, starting in 1997 These data are provided by NOAA. Principal investigators include Xin Lan (NOAA). Key partners include United Kingdom Meteorological Office (UKMO). Please cite the product's citation when using data from this dataset : Lan, X., J.W. Mund, A.M. Crotwell, K.W. Thoning, E. Moglia, M. Madronich, K. Baugh, G. Petron, M.J. Crotwell, D. Neff, S. Wolter, T. Mefford and S. DeVogel (2024), Atmospheric Nitrous Oxide Dry Air Mole Fractions from the NOAA GML Carbon Cycle Cooperative Global Air Sampling Network, 1997-2023, Version: 2024-07-30, https://doi.org/10.15138/53g1-x417 |
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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. |
DOI Metadata
| DOI |
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| For more information, please refer: doi.org/10.15138/53g1-x417 | |||||||||
Related information
| Format | Text (WDCGG Data Format Table, WDCGG Meteorological Data Format Table), NetCDF | ||||
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| Relation List (Is Part Of) |
All N2O data contributed to WDCGG by GAW stations and mobiles by 2024-09-24 All N2O data contributed to WDCGG by GAW stations and mobiles by 2023-09-13 All N2O data contributed to WDCGG by GAW stations and mobiles by 2022-09-05 All N2O data contributed to WDCGG by GAW stations and mobiles by 2021-08-24 All N2O data contributed to WDCGG by GAW stations and mobiles by 2020-09-28 All N2O data contributed to WDCGG by GAW stations and mobiles by 2019-09-19 All N2O data contributed to WDCGG by GAW stations and mobiles by 2018-10-23 |
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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.
Xin Lan (NOAA),
Atmospheric N2O
at Ascension Island by Global Monitoring Laboratory, NOAA
,
dataset published as N2O_ASC1007_
surface-flask_NOAA_ccgg at WDCGG,
ver. 2025-01-01-0002 (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 | Lan, X., J.W. Mund, A.M. Crotwell, K.W. Thoning, E. Moglia, M. Madronich, K. Baugh, G. Petron, M.J. Crotwell, D. Neff, S. Wolter, T. Mefford and S. DeVogel (2024), Atmospheric Nitrous Oxide Dry Air Mole Fractions from the NOAA GML Carbon Cycle Cooperative Global Air Sampling Network, 1997-2023, Version: 2024-07-30, https://doi.org/10.15138/53g1-x417 |
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