Abstract
We address the problem of the high-frequency correction of water vapour fluxes measured by eddy covariance with a closed-path infrared gas analyser (IRGA). Different transfer functions are compared and evaluated at a forested (Vielsalm, Belgium) and an agricultural (Lonzée, Belgium) site. Classical functions, usually applied to correct CO2 fluxes (Gaussian, Lorentzian), are found to be unsuited to water vapour cospectral corrections, being characterised by too sharp a decrease at high frequency. Two other functions characterised by a lower decreasing slope are found to better fit experimental transfer functions. They were calibrated and validated on experimental transfer functions and their dependency on air humidity is parameterised. On this basis, new correction coefficients are estimated. The coefficients are found to be larger than those based on the classical functions, even when the dependency of the latter on air humidity is taken into account. The difference amounts to 10% at the forested site and to 5% larger at the crop site. The study highlights the necessity of characterising the water transfer function shape and taking it into account in the correction factor at each site equipped with a closed path IRGA.
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Abbreviations
- RMSD:
-
Root-mean-square differences
- a j :
-
Parameter of regression for model j
- b j :
-
Parameter of regression for model j
- C :
-
Cospectrum
- C ref :
-
Cospectrum of reference
- C ws :
-
Cospectral density of two variables w and s
- \({C_{ws}^{\rm exp}}\) :
-
Experimental cospectral density of two variables w and s
- C wT :
-
STF cospectral density
- \({C_{wT}^{\rm exp}}\) :
-
Experimental STF cospectral density
- c :
-
CO2 concentration
- D s :
-
Vapour pressure deficit
- d j :
-
Parameter of regression for model j
- f :
-
Frequency
- f o :
-
Half-power frequency
- f o,s, j :
-
Half-power frequency for a scalar s and for model j
- g j :
-
Parameter of regression for model j
- h :
-
Water vapour concentration
- i j :
-
Parameter of regression for model j
- j :
-
Number of models
- k j :
-
Parameter of regression for model j
- L self :
-
Inductance
- N T,exp :
-
Normalisation factor of the measured STF cospectrum
- N s :
-
Normalisation factors of the cospectrum of variables w and s
- N s,exp :
-
Normalisation factors of the measured cospectrum of variables w and s
- s :
-
Scalar
- x j :
-
Exponent-parameter of model j
- w :
-
Vertical wind speed
- w′:
-
Fluctuation of the vertical wind speed
- δ s :
-
Transfer function of the scalar s
- \({\delta_s^{\rm exp}}\) :
-
Experimental transfer function of the scalar s
- ε s :
-
Correction factor for the flux of scalar s
References
Amiro BD (1990) Drag coefficients and turbulence spectra within three boreal forest canopies. Boundary-Layer Meteorol 52: 227–246
Ammann C, Brunner A, Spirig C, Neftel A (2006) Water vapour concentration and flux measurements with PTR-MS. Atmos Chem Phys 6: 4643–4651
Anderson DE, Verma SB, Clement RJ, Baldocchi DD, Matt DR (1986) Turbulence spectra of CO2, water vapour, temperature and velocity over a deciduous forest. Agric For Meteorol 38: 81–99
Aubinet M, Grelle A, Ibrom A, Rannik Ü, Moncrieff J, Foken T, Kowalski AS, Martin PH, Berbigier P, Bernhofer Ch, Clement R, Elbers J, Granier A, Grünwald T, Morgenstern K, Pilegaard K, Rebmann C, Snijders W, Valentini R, Vesala T (2000) Estimates of the annual net carbon and water exchange of forests: the EUROFLUX methodology. Adv Ecol Res 30: 113–175
Aubinet M, Chermanne B, Vandenhaute M, Longdoz B, Yernaux M, Laitat E (2001) Long term carbon dioxide exchange above a mixed forest in the Belgian Ardennes. Agric For Meteorol 108: 293–315
Aubinet M, Moureaux C, Bodson B, Dufranne D, Heinesch B, Suleau M, Vancutsem F, Vilret A (2009) Carbon sequestration by crop over a 4-year sugar beet/winter wheat/seed potato/winter wheat rotation cycle. Agric For Meteorol 149: 407–418
Baldocchi DD (2003) Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems: past, present and future. Glob Change Biol 9: 479–492
Clement R (2004) Mass and energy exchange of a plantation forest in Scotland using micrometeorological methods. PhD Thesis, University of Edinburgh, U.K., 382 pp
Cohen J, Cohen P, West SG, Aiken LS (2003) Applied multiple regression/correlation analysis for the behavioral sciences. Lawrence Erlbaum Associates Inc., Mahwah, NJ, pp 703
Dagnelie P (1970) Théorie et Méthodes Statistiques, vol II. Presses Agronomiques de Gembloux, Gembloux, Belgium, 378 pp
Eugster W, Senn W (1995) A co-spectral correction model for measurement of turbulent NO2 flux. Boundary-Layer Meteorol 74: 321–340
Foken T, Wichura B (1996) Tools for quality assessment of surface-based flux measurements. Agric For Meteorol 78: 83–105
Hiller R, Zeeman MJ, Eugster W (2008) Eddy-covariance flux measurements in the complex terrain of an alpine valley in Switzerland. Boundary-Layer Meteorol 127: 449–467
Horst TW (1997) A simple formula for attenuation of eddy fluxes measured with first-order-response scalar sensors. Boundary-Layer Meteorol 82: 219–233
Ibrom A, Dellwik E, Flyvbjerg H, Jensen NO, Pilegaard K (2007) Strong low-pass filtering effects on water vapour flux measurements with closed-path eddy correlation Systems. Agric For Meteorol 147: 140–156
Kaimal JC, Finnigan JJ (1994) Atmospheric boundary layer flows: their structure and measurement. Oxford University Press, U.K., pp 289
Kolle O, Rebmann C (2007) Eddysoft—documentation of a software package to acquire and process eddy covariance data. Technical Reports–Max-Planck-Institute für Biogeochemie, 10, 88 pp
Laitat E, Chermanne B, Portier B (2000) Biomass, carbon and nitrogen allocation in open top chambers under ambient and elevated co2 and in a mixed forest stand. A Tentative approach for scaling up from the experiments of Vielsalm. In: Ceulemans RJM, Veroustraete F, Gond V, Van Rensbergen JBHF (eds) Forest ecosystem modelling, upscaling and remote sensing. Academic Publishing, The Hague, The Netherlands, pp 33–60
Lenschow DH, Raupach MR (1991) The attenuation of fluctuations in scalar concentrations through sampling tubes. J Geophys Res 96: 15259–15268
Leuning R, Judd MJ (1996) The relative merits of open- and closed-path analysers for measurement of eddy fluxes. Glob Change Biol 2: 241–253
Leuning R, King KM (1992) Comparison of eddy co-variance measurements of CO2 fluxes by open- and closed-path CO2 analysers. Boundary-Layer Meteorol 59: 297–311
Leuning R, Moncrieff J (1990) Eddy-covariance CO2 flux measurements using open-path and closed-path CO2 analyzers—corrections for analyzer water-vapour sensitivity and damping of fluctuations in air sampling tubes. Boundary-Layer Meteorol 53: 63–76
Mammarella I, Launiainen S, Gronholm T, Keronen P, Pumpanen J, Rannik U, Vesala T (2009) Relative humidity effect on the high-frequency attenuation of water vapor flux measured by a closed-path eddy covariance system. J Atmos Oceanic Technol 26: 1852–1866
Massman WJ (1991) The attenuation of concentration fluctuations in turbulent flow through a tube. J Geophys Res 96(D8): 269–273
Massman WJ (2000) A simple method for estimating frequency response corrections for eddy covariance systems. Agric For Meteorol 104: 185–198
Massman WJ, Ibrom A (2008) Attenuation of concentration fluctuations of water vapor and other trace gases in turbulent tube flow. Atmos Chem Phys 8: 6245–6259
Moncrieff JB, Massheder JM, de Bruin H, Elbers J, Friborg T, Heusinkveld B, Kabat P, Scott S, Soegaard H, Verhoef A (1997) A system to measure surface fluxes of momentum, sensible heat, water vapour and carbon dioxide. J Hydrol 188/189: 589–611
Monji N, Inoue M, Hamotani K (1994) Comparison of eddy heat fluxes between inside and above a coniferous forest. J Agric Meteorol 50: 23–31
Moore CJ (1986) Frequency response corrections for eddy correlation systems. Boundary-Layer Meteorol 37: 17–35
Moureaux C, Debacq A, Bodson B, Heinesch B, Aubinet M (2006) Annual net ecosystem carbon exchange by a sugar beet crop. Agric For Meteorol 139: 25–39
Ohtaki E (1985) On the similarity in atmospheric fluctuations of carbon dioxide, water vapor and temperature over vegetated fields. Boundary-Layer Meteorol 32: 25–37
Panofsky HA, Dutton JA (1984) Atmospheric turbulence. Wiley, New York, pp 418
Ruppert J, Thomas C, Foken T (2006) Scalar similarity for relaxed eddy accumulation methods. Boundary-Layer Meteorol 120: 39–63
Stull RB (1988) An introduction to Boundary Layer Meteorology. Kluwer, Dordrecht, pp 666
Su HB, Schmid HP, Grimmond CSB, Vogel CS, Oliphant AJ (2004) Spectral characteristics and correction of long-term eddy-covariance measurements over two mixed hardwood forests in non-flat terrain. Boundary-Layer Meteorol 110: 213–253
Wilson K, Goldstein A, Falge E, Aubinet M, Baldocchi D, Berbigier P, Bernhofer C, Ceulemans R, Dolman H, Field C, Grelle A, Ibrom A, Law B, Kowalski A, Meyers T, Moncrieff J, Monson R, Oechel W, Tenhunen J, Valentini R, Verma S (2002) Energy balance closure at FLUXNET sites. Agric For Meteorol 113: 223–243
Wyngaard JC, Coté OR (1972) Co-spectral similarity in the atmospheric surface layer. Q J Roy Meteorol Soc 98: 590–603
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De Ligne, A., Heinesch, B. & Aubinet, M. New Transfer Functions for Correcting Turbulent Water Vapour Fluxes. Boundary-Layer Meteorol 137, 205–221 (2010). https://doi.org/10.1007/s10546-010-9525-9
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DOI: https://doi.org/10.1007/s10546-010-9525-9