Towards a Flux-Partitioning Procedure Based on the Direct Use of High-Frequency Eddy-Covariance Data
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Scanlon and Sahu (Water Resour Res 44(10):W10418, 2008) proposed an interesting method to estimate assimilation, respiration, evaporation and transpiration directly using high-frequency eddy-covariance measurements. In this note we critically revise this method and, in particular, using the Descartes’ rule of sign, we show that one branch of solutions can be directly neglected reducing the analytical complexity of the procedure. We also discuss the stability of the results of the method with respect to the input parameters, especially to the water-use efficiency.
KeywordsEvaporation Photosynthesis Respiration Transpiration Water-use efficiency
This work has been supported by the two Italian projects Biodati (D.M. 15421 4/07/2011) and CLIMESCO (FISR D.D. no. 285 20/02/2006). The experimental measurements are courtesy given by the National Research Project “Optimization of existing bioenergy chains for economic and environmental sustainability” (BIOSEA), funded by the Ministry of Agriculture, Food and Forestry Policies (MiPAAF), Italy. LP thanks the SSD PESCA and the RITMARE Italian Research Ministry (MIUR) Projects. DV has been supported by EC project ICOS-INWIRE (FPT/2007-2013, grant agreement n. 313169). We thank G. Lacorata for the suggestion of using the absolute value of \(\Delta \) in the numerical calculations.
- Bacon M (2004) Water use efficiency in plant biology. Blackwell, Oxford, 327 ppGoogle Scholar
- Baldocchi D, Falge E, Gu L, Olson R, Hollinger D, Running S, Anthoni P, Bernhofer C, Davis K, Evans R, Fuentes J, Goldstein A, Katul G, Law B, Lee X, Malhi Y, Meyers T, Munger W, Oechel W, Paw KT, Pilegaard K, Schmid HP, Valentini R, Verma S, Vesala T, Wilson K, Wofsy S (2001) FLUXNET: A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor, and energy flux densities. Bull Am Meteorol Soc 82:2415–2434CrossRefGoogle Scholar
- Dennis JE, Schnabel RB (1983), Numerical methods for unconstrained optimization and nonlinear equations. Prentice-Hall, Englewood Cliffs, 378 pp (Reprinted as Classics in applied mathematics, vol 16, 1996)Google Scholar
- Press WH, Teukolsky SA, Vetterling WT, Flannery BP (1992) Numerical recipes in C: the art of scientific computing. Cambridge University Press, Cambridge, 925 ppGoogle Scholar
- Reichstein M, Falge E, Baldocchi D, Papale D, Aubinet M, Berbigier P, Bernhofer C, Buchmann N, Gilmanov T, Granier A, Grüunwald T, Havránková 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, Valentini R (2005) On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm. Glob Change Biol 11:1424–1439CrossRefGoogle Scholar
- Reichstein M, Stoy PC, Desai AR, Lasslop G, Richardson AD (2012) Partitioning of net fluxes. In: Aubinet M et al. (eds) Eddy covariance: a practical guide to measurement and data analysis, Chap 9. Springer Atmospheric Sciences, Berlin, pp 263–289Google Scholar
- Scanlon TM, Sahu P (2008) On the correlation structure of water vapor and carbon dioxide in the atmospheric surface layer: a basis for flux partitioning. Water Resour Res 44:W10418Google Scholar