Advances in Science and Research www.adv-sci-res.net 1992-0628 1992-0636 3 8th EMS Annual Meeting and 7th European Conference on Applied Climatology 2008 2009 10.5194/asr-3-91-2009 http://www.adv-sci-res.net/3/91/2009/ http://www.adv-sci-res.net/3/91/2009/asr-3-91-2009.html http://www.adv-sci-res.net/3/91/2009/asr-3-91-2009.pdf 91 98 2009-05-18 Assessment of dispersion parameterizations through wind data measured by three sonic anemometers in a urban canopy L. Mortarini E. Ferrero R. Richiardone S. Falabino D. Anfossi S. Trini Castelli E. Carretto Dipartimento di Scienze e Tecnologie Avanzate, Università del Piemonte Orientale, Alessandria, Italy Dipartimento di Fisica Generale, Università di Torino, Italy C.N.R., Istituto di Scienze dell`Atmosfera e del Clima, Torino, Italy One year of continuous wind and turbulence measurements at three levels (5, 9 and 25 m) on a mast located in the suburb of the city of Turin were collected. Those recorded during April 2007 are analyzed and their main characteristics are presented and discussed. The analysis includes, at each level, mean, standard deviation, Skewness, Kurtosis for the 3-D wind components and sonic temperature. The integral time scales for the 3-D wind components are also computed and friction velocity and Monin-Obukhov length are determined as well. In particular, the wind standard deviation profiles as a function of stability are compared to the literature predictions for flat undisturbed terrain. It is found that, while the vertical component agrees reasonably well, the horizontal components deviate from the prescribed values, as expected considering the buildings and other obstacles effects and the high percentage of low-wind conditions. Also the integral time scales, estimated by the autocorrelation functions, are compared to the literature predictions, finding significant differences, again attributed to the low-wind speed occurrences. Anfossi, D., Oettl, D., Degrazia, G., and Goulart, A.: An analysis of sonic anemometer observations in low-wind speed conditions, Bound.-Lay. Meteorol., 114, 179–203, 2005. Baas, P., Steeneveld, G. J., van de Wiel, B. J. H., and Holtslag, A. A. M.: Exploring self-correlation in flux-gradient relationships for stably stratified conditions, J. Atmos. Sci., 63, 3045–3054, 2006. Degrazia, G. and Anfossi, D.: Estimation of the Kolmogorov constant C0 from classical statistical diffusion theory, Atmos. Environ., 32, 3611–3614, 1998. Degrazia, G., Anfossi, D., Carvalho, J., Mangia, C., Tirabassi, T., and Campos Velho, H.: Turbulence parameterisation for PBL dispersion models in all stability conditions, Atmos. Environ., 34, 3575–3583, 2000. Hanna, S.: Applications in air pollution modelling, in: Atmospheric Turbulence and Air Pollution Modelling, edited by: Nieuwstadt, F. and Van Dop H., Reidel, Dordrecht, 275–310, 1982. Maurizi, A.: On the dependence of third- and fourth-order moments on stability in the turbulent boundary layer, Nonlin. Processes Geophys., 13, 119–123, 2006. Moraes, O., Acevedo, O., Degrazia, G., Anfossi, D., da Silva, R., and Anabor, V.: Surface layer turbulence parameters over a complex terrain, Atmos. Environ., 39, 3103–3112, 2005. Nieuwstadt, F.: The turbulent structure of the stable nocturnal boundary layer, J. Atmos. Sci., 41, 2202–2216, 1984. Richiardone, R.: The transfer function of a differential microbarometer, J. Atmos. Ocean. Tech., 10, 624–628, 1993. Rotach, M. W.: On the influence of the urban roughness sublayer on turbulence and dispersion, Atmos. Environ., 33, 4001–4008, 1999. Kastner-Klein, P. and Rotach, M. W.: Mean flow and turbulence characteristics in an urban roughness sublayer, Bound.-Lay. Meteorol., 111, 55–84, 2004. Roth, M.: Review of atmospheric turbulence, Q. J. Roy. Meteor. Soc., 126, 941–990, 2000. Smedman, A.: Observations of a multi-level turbulence structure in a very stable boundary layer, Bound.-Lay. Meteorol., 44, 231–253, 1988. Tampieri, F., Maurizi, A., and Alberghi, S.: Lagrangian models of turbulent dispersion in the atmospheric boundary layer, in In-gegneria del vento in Italia 2000, INVENTO 2000 Proceedings, 37–50, 2000. Wyngaard, J. C. and Weil, J. C.: Transport asymmetry in skewed turbulence, Phys. Fluids A, 3, 155–162, 1991.