Biogeosciences www.biogeosciences.net 1726-4170 1726-4189 6 8 2009 10.5194/bg-6-1445-2009 http://www.biogeosciences.net/6/1445/2009/ http://www.biogeosciences.net/6/1445/2009/bg-6-1445-2009.html http://www.biogeosciences.net/6/1445/2009/bg-6-1445-2009.pdf 1445 1466 2009-08-07 Intercomparison and assessment of turbulent and physiological exchange parameters of grassland E. Nemitz en@ceh.ac.uk K. J. Hargreaves A. Neftel B. Loubet P. Cellier J. R. Dorsey M. Flynn A. Hensen T. Weidinger R. Meszaros L. Horvath U. Dämmgen C. Frühauf F. J. Löpmeier M. W. Gallagher M. A. Sutton Atmospheric Sciences, Centre for Ecology and Hydrology (CEH) Edinburgh, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK Swiss Federal Research Station for Agroecology and Agriculture (FAL-CH), Zürich-Reckenholz and Liebefeld-Bern, 3003 Bern, Switzerland Institut National de la Recherche Agronomique (INRA), UMR Environnement et Grandes Cultures, Thiverval-Grignon, 78850, France School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Simon Building, Oxford Road, Manchester, M13 9PL, UK (formerly known as: University of Manchester Institute of Science and Technology, UMIST). Energy research Centre of the Netherlands (ECN), Postbus 1, 1755 ZG Petten, The Netherlands Eötvös Loránd University, Department of Meteorology, 1117 Budapest, Hungary Hungarian Meteorological Service, 1675 Budapest, Hungary Institute for Agroecology, German Agricultural Research Institute, Braunschweig-Völkerode, Germany Agrometeorological Research Station of Deutscher Wetterdienst, Bundesallee 50, 38116 Braunschweig, Germany Commonly, the micrometeorological parameters that underline the calculations of surface atmosphere exchange fluxes (e.g. friction velocity and sensible heat flux) and parameters used to model exchange fluxes with SVAT-type parameterisations (e.g. latent heat flux and canopy temperature) are measured with a single set of instrumentation and are analysed with a single methodology. This paper evaluates uncertainties in these measurements with a single instrument, by comparing the independent results from nine different institutes during the international GRAMINAE integrated field experiment over agricultural grassland near Braunschweig, Lower Saxony, Germany. The paper discusses uncertainties in measuring friction velocity, sensible and latent heat fluxes, canopy temperature and investigates the energy balance closure at this site. Although individual 15-min flux calculations show a large variability between the instruments, when averaged over the campaign, fluxes agree within 2% for momentum and 11% for sensible heat. However, the spread in estimates of latent heat flux (&lambda;<i>E</i>) is larger, with standard deviations of averages of 18%. The dataset averaged over the different instruments fails to close the energy budget by 20%, significantly larger than the uncertainties in the individual flux corrections. However, if the largest individual turbulent flux estimates are considered, energy closure can be achieved, indicating that the closure gap is within the spread of the measurements. The uncertainty in &lambda;<i>E</i> feeds results in an uncertainty in the bulk stomatal resistance, which further adds to the uncertainties in the estimation of the canopy temperature that controls the exchange. The paper demonstrated how a consensus dataset was derived, which is used by the individual investigators to calculate fluxes and drive their models. % vor jede Referenz Aubinet, M., Grelle, A., Ibrom, A., Rannik, Ãœ., Moncrieff, J., Foken, T., Kowalski, A. S., Martin, P. H., Berbigier, P., Bernhofer, C., Clement, R., Elbers, J., Granier, A., Grunwald, T., Morgenstern, K., Pilegaard, K., Rebmann, C., Snijders, W., Valentini, R., and Vesala, T.: Estimates of the annual net carbon and water exchange of forests: The EUROFLUX methodology, Adv. Ecol. Res., 30, 113–175, 2000. % vor jede Referenz Barr, A. G., Morgenstern, K., Black, T. A., McCaughey, J. H., and Nesic, Z.: Surface energy balance closure by the eddy-covariance method above three boreal forst stands and implications for the measurement of the CO₂ flux, Agr. Forest Meteorol., 140, 322–337, doi:10.1016/j.agrformet.2006.08.007, 2006. % vor jede Referenz Burkhardt, J., Flechard, C. R., Gresens, F., Mattsson, M., Jongejan, P. A. C., Erisman, J. W., Weidinger, T., Meszaros, R., Nemitz, E., and Sutton, M. A.: Modelling the dynamic chemical interactions of atmospheric ammonia with leaf surface wetness in a managed grassland canopy, Biogeosciences, 6, 67–83, 2009. % vor jede Referenz Christen, A., van Gorsel, E., Andretta, M., Calanca, P., Rotach, M. W., and Vogt, R.: Intercomparison of ultrasonic anemometers during the MAP Riviera project, Ninth Conference on Mountain Meteorology, 7–12 August 2000, Aspen, Colorado, 2000. % vor jede Referenz Dämmgen, U., Grünhage, L., and Schaaf, S.: The precision and spatial variability of some meteorological parameters needed to determine vertical fluxes of air constituents, Landbauforschung Volkenrode, 55, 29–37, 2005. % vor jede Referenz Dutaur, L., Cieslik, S., Carrara, A., and Lopez, A.: The Detection of Nonstationarity in the Determination of Deposition Fluxes, Eurotrac, Garmisch-Partenkirchen; Germany, 171-176, CN030443471, 1998. % vor jede Referenz Dyer, A. J. and Hicks, B. B.: Flux-gradient relationships in the constant flux layer, Q. J. Roy. Meteor. Soc., 96, 715–721, 1970. % vor jede Referenz Dyer, A. J., Garratt, J. R., Francey, R. J., McIlroy, I. C., Bacon, N. E., Hyson, P., Bradley, E. F., Denmead, O. T., Tsvang, L. R., Volkov, Y. A., Koprov, B. M., Elagina, L. G., Sahashi, K., Monji, N., Hanafusa, T., Tsukamoto, O., Frenzen, P., Hicks, B. B., Wesely, M., Miyake, M., and Shaw, W.: An International Turbulence Comparison Experiment (Itce 1976), Bound.-Lay. Meteorol., 24, 181–209, 1982. % vor jede Referenz Finnigan, J. J., Clement, R., Malhi, Y., Leuning, R., and Cleugh, H. A.: A re-evaluation of long-term flux measurement techniques. Part I: Averaging and coordinate rotation, Bound.-Lay. Meteorol., 107, 1–48, 2003. % vor jede Referenz Flechard, C. R. and Fowler, D.: Atmospheric ammonia at a moorland site. II: Long-term surface- atmosphere micrometeorological flux measurements, Q. J. R. Meteor. Soc., 124, 759–791, 1998. % vor jede Referenz Foken, T., Wimmer, F., Mauder, M., Thomas, C., and Liebethal, C.: Some aspects of the energy balance closure problem, Atmos. Chem. Phys., 6, 4395–4402, 2006. % vor jede Referenz Foken, T.: Micrometeorology, Sprinter, 308 pp., 2008. % vor jede Referenz Fritschen, L. J., Qian, P., Kanemasu, E. T., Nie, D., Smith, E. A., Stewart, J. B., Verma, S. B., and Wesely, M. L.: Comparisons of Surface Flux Measurement Systems Used in Fife 1989, J. Geophys. Res.-Atmos., 97, 18697–18713, 1992. % vor jede Referenz Garland, J. A.: Dry Deposition of Sulfur-Dioxide to Land and Water Surfaces, P. Roy. Soc. A-Math. Phy., 354, 245–268, 1977. % vor jede Referenz Guenther, A., Karl, T., Harley, P., Wiedinmyer, C., Palmer, P. I., and Geron, C.: Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature), Atmos. Chem. Phys., 6, 3181–3210, 2006. % vor jede Referenz Hammerle, A., Haslwanter, A., Schmitt, M., Bahn, M., Tappeiner, U., Cernusca, A., and Wohlfahrt, G.: Eddy covariance measurements of carbon dioxide, latent and sensible energy fluxes above a meadow on a mountain slope, Bound.-Lay. Meteorol., 122, 397–416, 2007. % vor jede Referenz Hensen, A., Nemitz, E., Flynn, M. J., Blatter, A., Jones, S. K., Sørensen, L. L., Hensen, B., Pryor, S., Jensen, B., Otjes, R. P., Cobussen, J., Loubet, B., Erisman, J. W., Gallagher, M. W., Neftel, A., and Sutton, M. A.: Inter-comparison of ammonia fluxes obtained using the relaxed eddy accumulation technique, Biogeosciences Discuss., 5, 3965–4000, 2008. % vor jede Referenz Hensen, A., Loubet, B., Mosquera, J., van den Bulk, W. C. M., Erisman, J. W., Dämmgen, U., Milford, C., Löpmeier, F. J., Cellier, P., MikuÅ¡ka, P., and Sutton, M. A.: Estimation of NH₃ emissions from a naturally ventilated livestock farm using local-scale atmospheric dispersion modelling, Biogeosciences Discuss., 6, 825–862, 2009. % vor jede Referenz Herrmann, B., Mattsson, M., Jones, S. K., Cellier, P., Milford, C., Sutton, M. A., Schjoerring, J. K., and Neftel, A.: Vertical structure and diurnal variability of ammonia exchange potential within an intensively managed grass canopy, Biogeosciences, 6, 15–23, 2009. % vor jede Referenz Hogstrom, U. and Smedman, A.-S.: Accuracy of sonic anemometers: laminar wind-tunnel calibrations compared to atmospheric in situ calibrations against a reference instrument, Bound.-Lay. Meteorol., 111, 33–54, 2004. % vor jede Referenz Horst, T. W.: A simple formula for attenuation of eddy fluxes measured with first-order-response scalar sensors, Bound.-Lay. Meteorol., 82, 219–233, 1997. % vor jede Referenz Inagaki, A., Letzel, M. O., Raasch, S., and Kanda, M.: The impact of the surface heterogeneity on the energy imbalance: a study using LES, J. Meteorol. Soc. Jpn., 84, 187–198, 2006. % vor jede Referenz Jarvis, P. G.: The interpretation of the variation in leaf water potential and stomatal conductance found in canopies in the field, Philos. T. R. Soc. Lond., B273, 593–610, 1976. % vor jede Referenz Kaimal, J. C. and Finnigan, J. J.: Atmospheric boundary layer flows, Oxford University Press, New York, 1994. % vor jede Referenz Kanda, M., Inagaki, A., Letzel, M. O., Raasch, S., and Watanabe, T.: LES study of the energy imbalance problem with eddy covariance fluxes, Bound.-Lay. Meteorol., 110, 381–404, 2004. % vor jede Referenz Kormann, R. and Meixner, F. X.: An analytical footprint model for non-neutral stratification, Bound.-Lay. Meteorol., 99, 207–224, 2001. % vor jede Referenz Laubach, J. and Teichmann, U.: Surface energy budget variability: A case study over grass with special regard to minor inhomogeneities in the source area, Theor. Appl. Climatol., 62, 9–24, 1999. % vor jede Referenz Loubet, B., Milford, C., Hensen, A., Daemmgen, U., Erisman, J.-W., Cellier, P., and Sutton, M. A.: Advection of NH₃ over a pasture field and its effect on gradient flux measurements, Biogeosciences, 6, 1295–1309, 2009. % vor jede Referenz Mattsson, M., Herrmann, B., David, M., Loubet, B., Riedo, M., Theobald, M. R., Sutton, M. A., Bruhn, D., Neftel, A., and Schjoerring, J. K.: Temporal variability in bioassays of the stomatal ammonia compensation point in relation to plant and soil nitrogen parameters in intensively managed grassland, Biogeosciences, 6, 171–179, 2009. % vor jede Referenz Mauder, M. and Foken, T.: Ergebnisse verschiedener Turbulenzmessgeraetevergleiche, University of Bayreuth, Department for micrometeorology, Bayreuth, Germany, 2001. % vor jede Referenz Mauder, M., Liebethal, C., Goedecke, M., Leps, J.-P., Beyrich, F., and Foken, T.: Processing and quality control of flux data during LITFASS-2003, Bound.-Lay. Meteorol., 121, 67–88, 2006. % vor jede Referenz Mauder, M., Oncley., S. P., Vogt, R., Weidinger, T., Ribeiro, L., Bernhofer, C., Foken, T., Kohsiek, W., de Bruin, H. A. R., and Liu, H.: The energy blance experiment ebex-2000. Part II: Intercomparison of eddy-covariance sensors and post-field data processing methods, Bound.-Lay. Meteorol., 123, 29–54, 2007. % vor jede Referenz Mauder, M., Foken, T., Clement, R., Elbers, J. A., Eugster, W., Grünwald, T., Heusinkveld, B., and Kolle, O.: Quality control of CarboEurope flux data – Part 2: Inter-comparison of eddy-covariance software, Biogeosciences, 5, 451–462, 2008. % vor jede Referenz McMillen, R. T.: An eddy correlation technqiue with extended applicability to non-simple terrain, Bound.-Lay. Meteorol., 43, 231–245, 1988. % vor jede Referenz Meek, D. W., Prueger, J. H., Kustas, W. P., and Hatfield, J. L.: Determining meaningful differences for SMACEX eddy covariance measurements, J. Hydrometeorol., 6, 805–811, 2005. % vor jede Referenz Mészáros, R., Horváth, L., Weidinger, T., Neftel, A., Nemitz, E., Dämmgen, U., Cellier, P., and Loubet, B.: Measurement and modelling ozone fluxes over a cut and fertilized grassland, Biogeosciences Discuss., 6, 1069–1089, 2009. % vor jede Referenz Milford, C.: Dynamics of Atmospheric Ammonia Exchange with Intensively-Managed Grassland, School of Geosciences, University of Edinburgh, Edinburgh, 2004. % vor jede Referenz Milford, C., Theobald, M. R., Nemitz, E., Hargreaves, K. J., Horvath, L., Raso, J., Dämmgen, U., Neftel, A., Jones, S. K., Hensen, A., Loubet, B., Cellier, P., and Sutton, M. A.: Ammonia fluxes in relation to cutting and fertilization of an intensively managed grassland derived from an inter-comparison of gradient measurements, Biogeosciences, 6, 819–834, 2009. % vor jede Referenz Moncrieff, J. B., Massheder, J. M., de Bruin, H., Elbers, J., Friborg, T., Heusinkveld, B., Kabat, P., Scott, S., Soegaard, H., and Verhoef, A.: A system to measure surface fluxes of momentum, sensible heat, water vapour and carbon dioxide, J. Hydrol., 189, 589–611, 1997. % vor jede Referenz Nemitz, E., Milford, C., and Sutton, M. A.: A two-layer canopy compensation point model for describing bi-directional biosphere-atmosphere exchange of ammonia, Q. J. Roy. Meteorol. Soc., 127, 815–833, 2001. % vor jede Referenz Nemitz, E., Hargreaves, K. J., McDonald, A. G., Dorsey, J. R., and Fowler, D.: Micrometeorological measurements of the urban heat budget and CO₂ emissions on a city scale, Environ. Sci. Technol., 36, 3139–3146, 2002. % vor jede Referenz Nemitz, E., Dorsey, J. R., Flynn, M. J., Gallagher, M. W., Hensen, A., Erisman, J.-W., Owen, S. M., Dämmgen, U. and Sutton, M. A.: Aerosol fluxes and particle growth above managed grassland, Biogeosciences, accepted, 2009. % vor jede Referenz Oliphant, A. J., Grimmond, C. S. B., Zutter, H. N., Schmid, H. P., Su, H.-B., Scott, S. L., Offerle, B., Randolph, J. C., and Ehman, J.: Heat storage and energy balance fluxes for a temperate decidious forest, Agr. Forest Meteorol., 126, 185–201, 2004. % vor jede Referenz Oncley, S. P., Foken, T., Vogt, R., Kohsiek, W., DeBruin, H. A. R., Bernhofer, C., Christen, A., van Gorsel, E., Grantz, D., Feigenwinter, C., Lehner, I., Liebethal, C., Liu, H., Mauder, M., Pitacco, A., Ribeiro, L., and Weidinger, T.: The energy balance experiment EBEX-2000. Part I: overview and energy closure, Bound.-Lay. Meteorol., 123, 1–28, 2007. % vor jede Referenz Owen, P. R. and Thompson, W. R.: Heat transfer across rough surfaces, J. Fluid Mech., 15, 321–334, 1963. % vor jede Referenz Personne, E., Loubet, B., Herrmann, B., Mattsson, M., Schjoerring, J. K., Nemitz, E., Sutton, M. A., and Cellier, P.: SURFATM-NH3: a model combining the surface energy balance and bi-directional exchanges of ammonia applied at the field scale, Biogeosciences, 6, 1371–1388, 2009. % vor jede Referenz Schotanus, P., Nieuwstadt, F. T. M., and DeBruin, H. A. R.: Temperature measurement with a sonic anemometer and its application to heat and moisture fluctuations, Bound.-Lay. Meteorol., 26, 81–93, 1983. % vor jede Referenz Shuttleworth, W. J. and Wallace, J. S.: Evaporation from sparse crop – an energy combination theory, Q. J. Roy. Meteor. Soc., 111, 839–855, 1985. % vor jede Referenz Sutton, M. A., Fowler, D., and Moncrieff, J. B.: The Exchange of Atmospheric Ammonia with Vegetated Surfaces. 1. Unfertilized Vegetation, Q. J. Roy. Meteor. Soc., 119, 1023–1045, 1993. % vor jede Referenz Sutton, M. A., Schjorring, J. K., and Wyers, G. P.: Plant Atmosphere Exchange of Ammonia, Philos. T. R. Soc. Lond., 351, 261–276, 1995. % vor jede Referenz Sutton, M. A., Burkhardt, J. K., Guerin, D., Nemitz, E., and Fowler, D.: Development of resistance models to describe measurements of bi-directional ammonia surface-atmosphere exchange, Atmos. Environ., 32, 473–480, 1998. % vor jede Referenz Sutton, M. A., Milford, C., Nemitz, E., Theobald, M. R., Hill, P. W., Fowler, D., Schjoerring, J. K., Mattsson, M. E., Nielsen, K. H., Husted, S., Erisman, J. W., Otjes, R., Hensen, A., Mosquera, J., Cellier, P., Loubet, B., David, M., Genermont, S., Neftel, A., Blatter, A., Herrmann, B., Jones, S. K., Horvath, L., Fuhrer, E. C., Mantzanas, K., Koukoura, Z., Gallagher, M., Williams, P., Flynn, M., and Riedo, M.: Biosphere-atmosphere interactions of ammonia with grasslands: Experimental strategy and results from a new European initiative, Plant Soil, 228, 131–145, 2001. % vor jede Referenz Sutton, M. A., Nemitz, E., Milford, C., Campbell, C., Erisman, J. W., Hensen, A., Cellier, P., David, M., Loubet, B., Personne, E., Schjoerring, J. K., Mattsson, M., Dorsey, J. R., Gallagher, M. W., Horvath, L., Weidinger, T., Meszaros, R., Dämmgen, U., Neftel, A., Herrmann, B., Lehman, B. E., Flechard, C., and Burkhardt, J.: Dynamics of ammonia exchange with cut grassland: synthesis of results and conclusions of the GRAMINAE Integrated Experiment, Biogeosciences Discuss., 6, 1121–1184, 2009a. % vor jede Referenz Sutton, M. A., Nemitz, E., Theobald, M. R., Milford, C., Dorsey, J. R., Gallagher, M. W., Hensen, A., Jongejan, P. A. C., Erisman, J. W., Mattsson, M., Schjoerring, J. K., Cellier, P., Loubet, B., Roche, R., Neftel, A., Hermann, B., Jones, S. K., Lehman, B. E., Horvath, L., Weidinger, T., Rajkai, K., Burkhardt, J., Löpmeier, F. J., and Daemmgen, U.: Dynamics of ammonia exchange with cut grassland: strategy and implementation of the GRAMINAE Integrated Experiment, Biogeosciences, 6, 309–331, 2009b. % vor jede Referenz Tsvang, L. R., Zubkovskii, S. L., Kader, B. A., Kallistratova, M. A., Foken, T., Gerstmann, V., Przadka, A., Pretel, Y., Zeleny, Y., and Keder, J.: International Turbulence Comparison Experiment (Itce-81), Bound.-Lay. Meteorol., 31, 325–348, 1985. % vor jede Referenz van Dijk, A., Kohsiek, W., and DeBruin, H. A. R.: Oxygen sensitivity of krypton and Lyman-alpha hygrometers, J. Atmos. Ocean. Tech., 20, 143–151, 2003. % vor jede Referenz Webb, E. K.: Profile relationships: the log-linear range and extension to strong stability, Q. J. Roy. Meteor. Soc., 96, 67–90, 1970. % vor jede Referenz Webb, E. K., Pearman, G. I., and Leuning, R.: Correction of flux measurements for density effects due to heat and water vapour transfer, Q. J. Roy. Meteor. Soc., 106, 85–100, 1980. % vor jede Referenz Wesely, M. L. and Hicks, B. B.: Some factors that affect the deposition rates of sulfur dioxide and similar gases on vegeation, JAPCA J. Air Waste Ma., 27, 1110–1116, 1977. % vor jede Referenz Wieser, A., Fiedler, F., and Corsmeier, U.: The influence of the sensor design on wind measurements with sonic anemometer systems, J. Atmos. Ocean. Tech., 18, 1585–1608, 2001. % vor jede Referenz Wilczak, J., Oncley, S., and Stage, S. A.: Sonic anemometer tilt correction algorithms, Bound.-Lay. Meteorol., 99, 127–150, 2001. % vor jede Referenz Wilson, K., Goldstein, A., Falge, E., Aubinet, M., Baldocchi, D., Berbigier, P., Bernhofer, C., Ceulenmans, R., Dolman, H., Field, C., Grelle, A., Ibrom, A., Law, B. E., Kowalski, A., Meyers, T., Moncrieff, J., Monson, R., Oechel, W., Tenhunen, J., Valentini, R., and Verma, S.: Energy balance closure at FLUXNET sites, Agr. Forest Meteorol., 113, 223–243, 2002.