% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Post:186437,
      author       = {Post, H. and Hendricks-Franssen, Harrie-Jan and Graf,
                      Alexander and Schmidt, M. and Vereecken, H.},
      title        = {{U}ncertainty analysis of eddy covariance {CO}$_{2}$ flux
                      measurements for different {EC} tower distances using an
                      extended two-tower approach},
      journal      = {Biogeosciences discussions},
      volume       = {11},
      number       = {8},
      issn         = {1810-6285},
      address      = {Katlenburg-Lindau [u.a.]},
      publisher    = {Copernicus},
      reportid     = {FZJ-2015-00513},
      pages        = {11943 - 11983},
      year         = {2014},
      abstract     = {The use of eddy covariance CO2 flux measurements in data
                      assimilation and other applications requires an estimate of
                      the random uncertainty. In previous studies, the two-tower
                      approach has yielded robust uncertainty estimates, but care
                      must be taken to meet the often competing requirements of
                      statistical independence (non-overlapping footprints) and
                      ecosystem homogeneity when choosing an appropriate tower
                      distance. The role of the tower distance was investigated
                      with help of a roving station separated between 8 m and 34
                      km from a permanent EC grassland station. Random uncertainty
                      was estimated for five separation distances with an extended
                      two-tower approach which removed systematic differences of
                      CO2 fluxes measured at two EC towers. This analysis was made
                      for a dataset where (i) only similar weather conditions at
                      the two sites were included and (ii) an unfiltered one. The
                      extended approach, applied to weather-filtered data for
                      separation distances of 95 m and 173 m gave uncertainty
                      estimates in best correspondence with the independent
                      reference method The introduced correction for systematic
                      flux differences considerably reduced the overestimation of
                      the two-tower based uncertainty of net CO2 flux
                      measurements, e.g. caused by different environmental
                      conditions at both EC towers. It is concluded that the
                      extension of the two-tower approach can help to receive more
                      reliable uncertainty estimates because systematic
                      differences of measured CO2 fluxes which are not part of
                      random error are filtered out.},
      cin          = {IBG-3},
      ddc          = {570},
      cid          = {I:(DE-Juel1)IBG-3-20101118},
      pnm          = {246 - Modelling and Monitoring Terrestrial Systems: Methods
                      and Technologies (POF2-246) / 255 - Terrestrial Systems:
                      From Observation to Prediction (POF3-255)},
      pid          = {G:(DE-HGF)POF2-246 / G:(DE-HGF)POF3-255},
      typ          = {PUB:(DE-HGF)16},
      doi          = {10.5194/bgd-11-11943-2014},
      url          = {https://juser.fz-juelich.de/record/186437},
}