The true mean vertical wind velocity – a miracle?
Uta Moderow1, Christian Bernhofer1, Christian Feigenwinter2
1 Institute of Hydrology and Meteorology, Technische Universität Dresden, Germany
2 University of Basel, Institute of Meteorology, Climatology and Remote Sensing, Basel, Switzerland
2 University of Basel, Institute of Meteorology, Climatology and Remote Sensing, Basel, Switzerland
O 3.3 in Horizontal and vertical trace gas advection
06.10.2009, 16:00-16:25, Kutschenhaus
Estimation of advective fluxes is a challenging task. It requires a high amount of information as well as a careful data treatment and selection of the most suitable methods depending on site characteristics and in turn on available data. One crucial point in estimation of advective fluxes is the assessment of the mean vertical velocity (e.g. Heinesch et al. 2007; Vickers and Mahrt 2006) that is needed for the calculation of the vertical advection. Data of the advection experiments ADVEX (Feigenwinter et al. 2007) are used to calculate vertical velocities on the basis of different tilt correction methods or rotation algorithms (e.g. Lee 1998, Paw U et al. 2000, Wilczak et al. 2001). The ADVEX data give the possibility not only to compare different sites but also to compare measurements of four different towers at the same site. A comparison of these different methods clearly showed that the agreement between these methods at the same tower is satisfying but not between the towers. First results suggest a poor agreement between the tilt correction methods and an alternative method using the divergence of horizontal wind speed. Different vertical advection estimates are computed on the basis of the different calculated vertical velocities. They are compared to each other and are investigated with regard to plausibility.
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