A long term hourly eddy covariance dataset of consistently processed CO2 and H2O Fluxes from the Tibetan Alpine Steppe at Nam Co (2005 - 2019)


The data set contains nearly 15 years of eddy covariance data from an alpine steppe ecosystem on the central Tibetan Plateau.The data was processed following standardized quality control methods to allow for comparability between the different years of our record and with other data sets. To ensure meaningful estimates of ecosystem atmosphere exchange, careful application of the following correction procedures and analyses was necessary: (1) Due to the remote location, continuous maintenance of the eddy covariance (EC) system was not always possible, so that cleaning and calibration of the sensors was performed irregularly. Furthermore, the high proportion of bare soil and high wind speeds led to accumulation of dirt in the measurement path of the infrared gas analyzer (IRGA). The installation of the sensor in such a challenging environment resulted in a considerable drift in CO2 and H2O gas density measurements. If not accounted for, this concentration bias may distort the estimation of the carbon uptake. We applied a modified drift correction procedure following Fratini et al. (2014) which, instead of a linear interpolation between calibration dates, uses the CO2 concentration measurements from the Mt. Waliguan atmospheric observatory as reference time series. (2) We applied rigorous quality filtering of the calculated fluxes to retain only fluxes which represent actual physical processes. (3) During the long measurement period, there were several buildings constructed in the near vicinity of the EC system. We investigated the influence of these obstacles on the turbulent flow regime to identify fluxes with uncertain land cover contribution and exclude them from subsequent computations. (4) We calculated the de-facto standard correction for instrument surface heating during cold conditions (hereafter called sensor self heating correction) following Burba et al. (2008) and a revision of the original method following Frank and Massman (2020). (5)Subsequently, we applied the traditional and widely used gap filling procedure following Reichstein et al. (2005) to provide a more complete overview of the annual net ecosystem CO2 exchange.(6) We estimated the flux uncertainty by calculating the random flux error (RE) following Finkelstein and Sims (2001) and by using the standard deviation of the fluxes used for gap filling(NEE_fsd) as a measure for spatial and temporal variation.


Data file naming and use method

File name: NAMORS_EC_2005-2019.csv. The file contains the EddyPro full_output (https://www.licor.com/env/support/EddyPro/topics/output-files-full-output.html) and biomet data, quality flags for quality filtering and fetch filtering, the CO2 fluxes corrected for sensor self heating effects, random uncertainty measures as propagated via WPL correction and the REddyProc gap filling results (https://www.bgc-jena.mpg.de/bgi/index.php/Services/REddyProcWebOutput).
File name: NAMORS_EC_2005-2019_varnames_units.csv. The file contains the variable descriptions and physical units for the above mentioned dataset.
Version 2 with enhanced calculations and data processing after peer-review(https://essd.copernicus.org/preprints/essd-2020-63/#discussion). The file "NAMORS_EC_2005-2019_v2.txt" contains the EddyProfull_output (https://www.licor.com/env/support/EddyPro/topics/output-files-full-output.html)and biomet data, quality flags for quality filtering, the CO2fluxes corrected for sensor self heating effects and the REddyProcgap filling results(https://www.bgc-jena.mpg.de/bgi/index.php/Services/REddyProcWebOutput).The file "NAMORS_EC_2005-2019_varnames_units_v2.txt" contains thevariable descriptions and physical units for the above mentioneddataset. The uploaded files are tab-delimited .txt files with"-9999" representing missing data.


Required Data Citation View Data Cite Help About Data Citation
Cite as:

Felix Nieberding, Yaoming MA, Cristian Wille, Gerardo Fratini, Magnus Ole Asmussen, Yuyang Wang*, Weiqiang Ma*, Torsten Sachs. A long term half-hourly eddy covariance dataset of consistently processed CO2 and H2O Fluxes from the Tibetan Alpine Steppe at Nam Co (2005 - 2019). National Tibetan Plateau Data Center, 2020. doi: 10.11888/Meteoro.tpdc.270333. (Download the reference: RIS | Bibtex )

Related Literatures:

1. Nieberding, F., Wille, C., Fratini, G., Asmussen, M. O., Wang, Y., Ma, Y., and Sachs, T.: A Long Term (2005–2019) Eddy Covariance Data Set of CO2 and H2O Fluxes from the Tibetan Alpine Steppe, Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2020-63, in review, 2020( View Details | Bibtex)

2. Ma, Y.M., Kang, S.C., Zhu, L.P., Xu, B.Q., Tian, L.D., & Yao, T.D. (2008). Tibetan Observation and Research Platform- Atmosphere–land interaction over a heterogeneous landscape, Bulletin of the American Meteorological Society. 89, 1487–1492. doi:10.1175/2008BAMS2545.1.( View Details | Bibtex)

3. Ma, Y.M., Ma, W.Q., Zhong, L., Hu, Z., Li, M., Zhu, Z., et al. (2017). Monitoring and Modeling the Tibetan Plateau’s climate system and its impact on East Asia, Scientific Reports, 7, 44574, doi:10.1038/srep44574.( View Details | Bibtex)

Using this data, the data citation is required to be referenced and the related literatures are suggested to be cited.


References literature

1.Burba, G. G., McDermitt, D. K., Grelle, A., Anderson, D., and XU, L. (2008). Addressing the influence of instrument surface heat exchange on the measurements of CO 2 flux from open-path gas analyzers, Global Change Biology, 14, 1854–1876, https://doi.org/10.1111/j.1365-2486.2008.01606.x. (View Details )

2.Fratini, G., McDermitt, D. K., and Papale, D. (2004). Eddy-covariance flux errors due to biases in gas concentration measurements: origins, quantification and correction, Biogeosciences, 11, 1037–1051, https://doi.org/10.5194/bg-11-1037-2014. (View Details )

3.Reichstein, M., Falge, E., Baldocchi, D., Papale, D., Aubinet, M., Berbigier, P., Bernhofer, C., Buchmann, N., Gilmanov, T., Granier, A., Grunwald, T., Havrankova, K., Ilvesniemi, H., Janous, D., Knohl, A., Laurila, T., Lohila, A., Loustau, D., Matteucci, G., Meyers, T., Miglietta, F., Ourcival, J.-m., Pumpanen, J., Rambal, S., Rotenberg, E., Sanz, M., Tenhunen, J., Seufert, G., Vaccari, F., Vesala, T., Yakir, D., and valentini, R. (20050. On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm, Global Change Biology, 11, 1424–1439, https://doi.org/10.1111/j.1365-2486.2005.001002.x. (View Details )


Support Program

Pan-Third Pole Environment Study for a Green Silk Road-A CAS Strategic Priority A Program (No:XDA20000000)

Second Tibetan Plateau Scientific Expedition Program

The Strategic Priority Research Program of Chinese Academy of Sciences (No:XDA20060101) [XDA20060101]

User Limit

To respect the intellectual property rights, protect the rights of data authors,expand servglacials of the data center, and evaluate the application potential of data, data users should clearly indicate the source of the data and the author of the data in the research results generated by using the data (including published papers, articles, data products, and unpublished research reports, data products and other results). For re-posting (second or multiple releases) data, the author must also indicate the source of the original data.

Example of acknowledgement statement is included below: The data set is provided by National Tibetan Plateau Data Center (http://data.tpdc.ac.cn).


License: This work is licensed under an Attribution 4.0 International (CC BY 4.0)


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Keywords
Geographic coverage
East: 90.96 West: 90.96
South: 30.77 North: 30.77
Detail
  • Temporal resolution: Hourly
  • Spatial resolution: 10m - 100m
  • File size: 250 MB
  • Browse count: 1,241 Times
  • Apply count: 20 Times
  • Share mode: online
  • Temporal coverage: 2005-12-04 To 2019-09-07
  • Temporal coverage: 2019-09-07 11:00 CST
  • Updated time: 2020-03-12
Contact Information
: Felix Nieberding   Yaoming MA   Cristian Wille   Gerardo Fratini   Magnus Ole Asmussen   Yuyang Wang*   Weiqiang Ma*   Torsten Sachs  

Distributor: National Tibetan Plateau Data Center

Email: data@itpcas.ac.cn

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