Geoökologisches Kolloquium SS 2003

Alle Termine

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Prof. Dr. G.N. Panin
Institute of Water Problem, Moscow
Donnerstag, 26.06.2003 16:15 H6

Interaction between Atmosphere and Natural Land Surface: Analysis of Data, Parametrization of Surface Fluxes and Applications for local Climate Models

Experimental data during last ten years show imbalances of the energy budget . Measurements of all components of the balance equation of heat, averaged over half hour periods, show that, within the framework of the used measuring techniques, the heat balance is not closed. The sum of fluxes of heat which is going into the atmosphere is less than . The main cause of this systematic imbalance is not the experimental methodology but a conceptual deficiency. It is related to the fact that the energy-mass exchange between the complex (horizontally inhomogeneous) land surface and the atmosphere is determined by applying theories that are based on the hypothesis of stationary and horizontal homogeneity (SHH).
Using the experimental results it was detected that the underestimation of the turbulent fluxes is related to the terrain inhomogeneity. To systematize the correction for this effect a parameterization is suggested which empirically makes use of the involved inhomogenity scale in the environment of a site. For parameterization of the energy imbalance the coefficient is used. The average value is in line with the data of FIFE, KUREX TARTEX, SADE, Cabouw and Anchor data.
The paper aims to serve as a contribution to the ongoing discussion on how to account for different types and scales of land surface inhomogeneities inside cells of models such as global climate models, as well as mesoscale models.




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