Article
 

Empirical assessment of uncertainties of meteorological parameters and turbulent fluxes in the AmeriFlux network

Pubblico Deposited

Contenuto scaricabile

Scarica il pdf
https://ir.library.oregonstate.edu/concern/articles/s4655h04f

Descriptions

Attribute NameValues
Creator
Abstract
  • Terrestrial ecosystem-atmosphere exchange of carbon, water vapor, and energy has been measured for over a decade at many sites globally. To minimize measurement and analysis errors, quality assurance data have been collected over short periods along-side tower instruments at AmeriFlux research sites. Theoretical and empirical error and uncertainty values have been reported for various aspects of the eddy covariance technique but until recently it has not been possible to constrain network level variation based on direct comparison of side-by-side measurements. Paired observations, although rare in practice, offer a possibility to obtain real-world error estimates for flux observations and corresponding uncertainties. In this study, we report the relative instrumental errors from the AmeriFlux quality assurance and quality control (QA/QC) site intercomparisons of 84 site visits (2002–2012). Relative errors, including random and systematic instrumental errors, are presented for meteorological and radiation variables, gas concentrations, and the turbulent fluxes. The lowest relative errors (<2%) were found for the meteorological parameters, while the largest relative errors were found for latent heat and CO₂ fluxes. The mean relative instrumental error for CO₂ flux averaged −8.2% (underestimation by the tower instruments). Sensible and latent heat fluxes exhibited mean errors of −1.7% and −5.2%, respectively. Deviation around the mean was also largest for the turbulent fluxes, approaching 20%. Because the data collected during QA/QC site visits are used to identify and correct errors, our results represent a conservative estimate of instrumental errors in the AmeriFlux database. Overall, the presented results confirm the high quality of the network data and underline its status as a valuable data source for the research community.
  • Keywords: uncertainties, AmeriFlux, random error, instrumental error, Fluxnet, eddy covariance
  • Keywords: uncertainties, AmeriFlux, random error, instrumental error, Fluxnet, eddy covariance
Resource Type
DOI
Date Available
Date Issued
Citation
  • Schmidt, A., C. Hanson, W. S. Chan, and B. E. Law (2012), Empirical assessment of uncertainties of meteorological parameters and turbulent fluxes in the AmeriFlux network, Journal of Geophysical Research, 117, G04014, doi:10.1029/2012JG002100.
Journal Title
Journal Volume
  • 117
Journal Issue/Number
  • G4
Academic Affiliation
Dichiarazione dei diritti
Funding Statement (additional comments about funding)
  • This research was supported by the Office of Science (BER), U.S. Department of Energy (grant DE-FG02-06ER64307).
Publisher
Peer Reviewed
Language
Replaces

Le relazioni

Parents:

This work has no parents.

Elementi

Thumbnail Titolo Data caricata Visibilità Azioni
file details SchmidtAndresForestryEmpiricalAssessmentUncertainties.pdf 2017-07-06 Pubblico Scaricare