Boundary-Layer Meteorology

, Volume 147, Issue 2, pp 329–335 | Cite as

A Comment on “How Well Can We Measure the Vertical Wind Speed? Implications for Fluxes of Energy and Mass” by Kochendorfer et al.

  • Matthias MauderEmail author


Kochendorfer et al. (Boundary-Layer Meterol, 145:383–398, 2012) conducted an experiment to evaluate azimuth and angle-of-attack dependent errors of sonic anemometer measurements. Several questions are raised regarding the experimental design and the presented results. The finding that instruments with non-orthogonal sonic paths underestimate fluctuations of vertical wind speed and consequently also scalar fluxes by about 10 % is compared with the results of a hitherto unpublished side-by-side field comparison and other past intercomparison experiments. Scale considerations are presented that raise considerable doubts on the validity of the implicit assumption of Kochendorfer et al. (2012) that the turbulent wind vector is highly correlated across a distance of 1.2 m at a height of 2.5 m over flat grassland, which corresponds to the separation between the sonic anemometers tested in their experiment. Nevertheless, new developments in sonic anemometer design to minimize transducer-shadow effects are desirable.


Angle-of-attack error Energy balance closure Field intercomparison  Sonic anemometer Transducer-shadow effects 



We would like to acknowledge Dr. Ray Desjardins and Dr. Elisabeth Pattey who provided the instruments for the intercomparison experiment. Thanks to Dr. Hans Peter Schmid and Dr. Matthias Zeeman for sharing their thoughts and for valuable discussions.


  1. Beyrich F (2000) LITFASS-98 Experiment, 25.5.1998–30.6.1998, Experimental report. Deutscher Wetterdienst, Forschung und Entwicklung, Arbeitsergebnisse 62:78Google Scholar
  2. Foken T (2008) The energy balance closure problem—an overview. Ecol Appl 18:1351–1368CrossRefGoogle Scholar
  3. Foken T, Jegede OO, Weisensee U, Richter SH, Handorf D, Görsdorf U, Vogel G, Schubert U, Kirzel HJ, Thiermann V (1997) Results of the LINEX-96/2 Experiment. Deutscher Wetterdienst, Forschung und Entwicklung, Arbeitsergebnisse 48:75Google Scholar
  4. Högström U, Smedman AS (2004) Accuracy of sonic anemometers: laminar wind-tunnel calibrations compared to atmospheric in situ calibrations against a reference instrument. Boundary-Layer Meteorol 111:33–54Google Scholar
  5. Kochendorfer J, Meyers TP, Frank J, Massman WJ, Heuer MW (2012) How well can we measure the vertical wind speed? Implications for fluxes of energy and mass. Boundary-Layer Meteorol 145:383–398. doi: 10.1007/s10546-012-9738-1 CrossRefGoogle Scholar
  6. Lenschow DH, Mann J, Kristensen L (1994) How long is long enough when measuring fluxes and other turbulence statistics? J Atmos Oceanic Technol 11:661–673CrossRefGoogle Scholar
  7. Mauder M, Oncley SP, Vogt R, Weidinger T, Ribeiro L, Bernhofer C, Foken T, Kohsiek W, de Bruin HAR, Liu H (2007) The Energy Balance Experiment EBEX-2000 Part II: intercomparison of eddy-covariance sensors and post-field data processing methods. Boundary-Layer Meteorol 123:29–54CrossRefGoogle Scholar
  8. Mauder M, Foken T, Clement R, Elbers JA, Eugster W, Grünwald T, Heusinkveld B, Kolle O (2008) Quality control of CarboEurope flux data—part 2: inter-comparison of eddy-covariance software. Biogeosciences 5:451–462CrossRefGoogle Scholar
  9. Mauder M, Desjardins RL, Pattey E, Worth D (2010) An attempt to close the surface energy balance by spatially-averaged flux measurements. Boundary-Layer Meteorol 136:175–191CrossRefGoogle Scholar
  10. Nakai T, Shimoyama K (2012) Ultrasonic anemometer angle of attack errors under turbulent conditions. Agric For Meteorol 162–163:14–26CrossRefGoogle Scholar
  11. Nakai T, van der Molen MK, Gash JHC, Kodama Y (2006) Correction of sonic anemometer angle of attack errors. Agric For Meteorol 136:19–30CrossRefGoogle Scholar
  12. Wilczak JM, Oncley SP, Stage SA (2001) Sonic anemometer tilt correction algorithms. Boundary-Layer Meteorol 99:127–150CrossRefGoogle Scholar
  13. Wyngaard JC, Zhang SF (1985) Transducer-shadow effects on turbulence spectra measured by sonic anemometers. J Atmos Oceanic Technol 2:548–558Google Scholar
  14. Zhang SF, Wyngaard JC, Businger JA, Oncley SP (1986) Response characteristics of the U.W. sonic anemometer. J Atmos Oceanic Technol 3:315–323Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  1. 1.Karlsruhe Institute of Technology (KIT)Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU)Garmisch-PartenkirchenGermany

Personalised recommendations