Theoretical and Applied Climatology

, Volume 119, Issue 3–4, pp 733–755 | Cite as

Spatial source attribution of measured urban eddy covariance CO2 fluxes

  • B. CrawfordEmail author
  • A. Christen
Original Paper


Interpretation of tower-based eddy covariance (EC) carbon dioxide flux (F C ) measurements in urban areas is challenging because of the location bias of EC instruments. This bias results from EC point measurements taken above a complex CO2 source/sink surface that is spatially heterogeneous at scales approaching or exceeding those of the turbulent flux source areas. This makes it difficult to accomplish traditional measurement objectives such as calculating spatially unbiased ecosystem-wide cumulative F C totals or objectively comparing F C during different environmental conditions (e.g., day vs. night or seasonal differences). This study uses a multiyear F C dataset measured over a residential area of Vancouver, BC, Canada from a 30-m flux tower in close proximity to a busy traffic intersection on one side. The F C measurements are analyzed using surface geospatial data and turbulent flux source area models to exploit location bias to develop methods to statistically model individual emissions and uptake processes in terms of environmental controls and surface land cover. The empirical relations between controls and measured F C are used to spatially and temporally downscale individual CO2 emissions/uptake processes that are then used to create high-resolution maps (20 m) and calculate ecosystem-wide F C at temporal resolutions of 30 min to 1 year. At this site, the modeled ecosystem-wide annual net F C total is calculated as 6.42 kg C m−2 year−1 with traffic emissions estimated to account for 68.8 % of the total net emissions. Building sources contribute 27.9 %, respiration from soil and vegetation is 5.5 %, respiration from humans 5.0 %, and photosynthesis offsets are −7.2 % of the annual net total. The statistical models developed here are then tested by direct comparison to independent EC measurements using land cover scalings derived from 30-min source area models. Results are also scaled to ecosystem-averaged land cover to compare results to independent emissions/uptake models.


Land Cover Source Area Leaf Area Index Eddy Covariance Flux Tower 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The current research was funded by the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS) as part of the network Environmental Prediction in Canadian Cities (EPiCC) and by an NSERC Discovery Grant “Direct measurement of greenhouse gas exchange in urban ecosystems.” Selected research infrastructure on the tower was supported by NSERC RTI and CFI/BCKDF. We acknowledge the support of the City of Vancouver and Environment Canada for providing additional data and BC Hydro for granting access to the tower site.

We further acknowledge the significant scientific, technical, and administrative support of staff and students at the University of British Columbia in providing remote sensing data, geospatial data and supporting the technical aspects of the long-term measurements: N. Coops, N. Goodwin, E. Heyman, R. Ketler, S. Lapsky, K. Liss, Z. Nesic, J. Ranada, C. Siemens, M. van der Laan and R. Tooke.


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Copyright information

© Springer-Verlag Wien 2014

Authors and Affiliations

  1. 1.Department of GeographyUniversity of British ColumbiaVancouverCanada
  2. 2.Department of Geography / Atmospheric Science ProgramUniversity of British ColumbiaVancouverCanada

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