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Autoregressive filtering versus linear detrending in estimation of fluxes by the eddy covariance method

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Abstract

The application of autoregressive running mean filtering (RMF) and linear detrending (LDT) in the estimation of turbulent fluxes by the eddy covariance method is analysed. The systematic, as well as the random, errors of the fluxes arising from filtering and/or limited observation time effects are described. To observe negligible systematic errors in fluxes, the RMF has to be applied with moderately long time constants. However, the obtained flux values are subject to increased random errors during periods of non-stationarity and the method leads to systematic overestimation of variances. These shortcomings are not inherent in the LDT approach, which is recommended for use. But the systematic errors of fluxes due to LDT are not negligible under certain experimental conditions and have to be accounted for. The corrections are important because the relatively small errors in short-period fluxes can translate to significant errors in long-period averages. The corrections depend on the turbulence time scales, which should be preferably estimated as ensemble mean variables for a particular site.

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References

  • Foken, Th. and Wichura, B.: 1996, ‘Tools for Quality Assessment of Surface-Based Flux Measurements', Agric. For. Meteorol. 78, 83-105.

    Google Scholar 

  • Gash, J. H. C. and Culf, A. D.: 1996, ‘Applying a Linear Detrend to Eddy Correlation Data in Real Time', Boundary-Layer Meteorol. 79, 301-306.

    Google Scholar 

  • Horst, T. W.: 1997, ‘A Simple Formula for Attenuation of Eddy Fluxes Measured with First-Order-Response Scalar Sensors', Boundary-Layer Meteorol. 82, 219-233.

    Google Scholar 

  • Kaimal, J. C. and Finnigan, J. J.: 1994, Atmospheric Boundary Layer Flows. Their Structure and Measurement, Oxford University Press, New York, 289 pp.

    Google Scholar 

  • Kaimal, J. C., Wyngaard, J. C., Izumi, Y., and Cote, O. R.: 1972, ‘Spectral Characteristics of Surface-Layer Turbulence', Quart. J. Roy. Meteorol. Soc. 98, 563-589.

    Google Scholar 

  • Kristensen, L.: 1998, Time Series Analysis. Dealing with Imperfect Data, Risø National Laboratory, Risø-I-1228(EN), 31 pp.

  • Lee, X.: 1996, ‘Turbulence Spectra and Eddy Diffusivity over Forests', J. Appl. Meteorol. 35, 1307-1318.

    Google Scholar 

  • Lee, X.: 1998, ‘On Micrometeorological Observations of Surface-Air Exchange over Tall Vegetation', Agric. For. Meteorol. 91, 39-49.

    Google Scholar 

  • Lenschow, D. H. and Kristensen, L.: 1985, ‘Uncorrelated Noise in Turbulence Measurements', J. Atmos. Oceanic Tech. 2, 68-81.

    Google Scholar 

  • Lenschow, D. H., Mann, J., and Kristensen, L.: 1994, ‘How Long Is Long Enough when Measuring Fluxes and Other Turbulence Statistics?', J. Atmos. Oceanic Tech. 18, 661-673.

    Google Scholar 

  • McMillen, R. T.: 1988, ‘An Eddy Correlation Technique with Extended Applicability to Non-Simple Terrain', Boundary-Layer Meteorol. 43, 231-245.

    Google Scholar 

  • Moncrieff, J. B., Massheder, J. M., De Bruin, H., Elbers, J., Friborg, T., Huesunkveld, B., Kabat, P., Scott, S., Soegaard, H., and Verhoef, A.: 1997, ‘A System to Measure Surface Fluxes of Momentum, Sensible Heat, Water Vapour and Carbon Dioxide', J. Hydrol. 189, 589-611.

    Google Scholar 

  • Monin, A. S. and Yaglom, A. M.: 1971, Statistical Fluid Mechanics, Vol. 1, MIT Press, 769 pp.

  • Moore, C. J.: 1986, ‘Frequency Response Corrections for Eddy Correlation Systems', Boundary-Layer Meteorol. 37, 17-35.

    Google Scholar 

  • Rannik, Ü.: 1998, ‘On the Surface Layer Similarity at a Complex Forest Site', J. Geophys. Res. 103, 8685-8697.

    Google Scholar 

  • Shuttleworth, W. J.: 1980, ‘Corrections for the Effect of Background Concentration Change and Sensor Drift in Real-Time Eddy Correlation Systems', Boundary-Layer Meteorol. 42, 167-180.

    Google Scholar 

  • Webb, E. K., Pearman, G. I., and Leuning, R.: 1980, ‘Correction of Flux Measurements for Density Effects Due To Heat and Water Vapour Transfer', Quart. J. Roy. Meteorol. Soc. 106, 85-100.

    Google Scholar 

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Authors and Affiliations

  1. Department of Physics, University of Helsinski, Helsinski, Finland

    Üllar Rannik & Timo Vesala

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  1. Üllar Rannik
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  2. Timo Vesala
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Rannik, Ü., Vesala, T. Autoregressive filtering versus linear detrending in estimation of fluxes by the eddy covariance method. Boundary-Layer Meteorology 91, 259–280 (1999). https://doi.org/10.1023/A:1001840416858

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