Parametrization of Surface Heterogeneities on Large Eddy Scales

With the help of large eddy simulation, we investigate the influences of surface heterogeneity on the structure of atmospheric boundary layers. In the first part of this study, we attempt to answer the question how surface heterogeneities can be characterized. One of our approaches is to describe the heterogeneity by making use of the Shannon Entropy originally used to quantify the degree of order of information. Based on the entropy analysis, we decompose a heterogeneous land surface into surfaces with fine and coarse structures. In the second part, numerical simulations using a large eddy model are carried out for these various surface types. We then use the numerical results to investigate how surface heterogeneity propagates into the atmosphere and on the basis of the atmospheric response to the surfaces of different complexities, we determine which scale of the heterogeneity plays an important role in the atmosphere and land surface interactions.