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DY: Fachverband Dynamik und Statistische Physik

DY 16: Fluid dynamics I

DY 16.3: Vortrag

Mittwoch, 25. März 2009, 15:15–15:30, ZEU 255

Statistical analysis of non-stationary atmospheric boundary layer turbulence — •Thomas Laubrich and Holger Kantz — Max-Planck-Institut fuer Physik Komplexer Systeme; Noethnitzer Str. 38, 01187 Dresden, Germany

We study the statistics of the horizontal component of atmospheric boundary layer wind speed. Motivated by its non-stationarity, we investigate which parameters remain constant or can be regarded as being piece-wise constant and explain how to estimate them. We will verify the picture of natural atmospheric boundary layer turbulence to be composed of successively occurring close to ideal turbulence with different parameters.

The first focus is put on the fluctuation of wind speed around its mean behaviour. We describe a method estimating the proportionality factor between the standard deviation of the fluctuation and the mean wind speed and analyse its time dependence. The second focus is put on the wind speed increments. We investigate the increment statistics and show that the parameters describing the distribution change with time by using superstatistics and simulated annealing optimisation.