Uni-Bayreuth grafik-uni-bayreuth



The spectral dimension of time series and its implication on flux estimates

Lukas Siebicke1, Martina Hunner1, Andrei Serafimovich1, Thomas Foken1
1 Abt. Mikrometeorologie, Universität Bayreuth

O 1.2 in Funktion von Ökosystemen

02.04.2009, 09:30-09:45, H8

Fluxes of energy and matter have a turbulent flux component and an advective flux component. A temporal windows is used as a reference for mean conditions of wind vector and scalar concentration. Given a time series composed of different wavelengths, the choice of this reference window acts as a wave length filter. When calculating fluxes there is a trade off between resolution and the maximum wave length contained. We propose to use spectral analysis to identify wave lengths relevant for a particular study. Furthermore, we suggest to represent a given signal as a composite of different wave length contributions. This study shows how the choice of different reference periods for wind field rotation by the planar fit method can effect advection estimates during the EGER Experiment. Similarly, the impact on long term eddy covariance CO2 flux estimates is presented.

Letzte Änderung 08.03.2009