Talk, EGU General Assembly 2011, Vienna: 2011-04-03 - 2011-04-08
Recently it has been found that the low frequency part of the turbulence spectrum has a signiﬁcant effect to the energy balance closure problem. In this study, a modiﬁed ogive analysis has been developed and applied to the low frequency data from selected measuring stations of the LlTFASS-2003 experiment. The aim of this analysis is to investigate whether the extension of the averaging time can really solve the energy balance closure problem. The effect of the low frequency part of the turbulence spectrum over different surfaces was also considered, as each selected station represents a different land use type. It was found that the extension of the averaging time (longer than 30 minutes) can improve energy balance closure for some sites but does not solve this problem for eddy covariance measurements in the surface layer in general.