Friction velocityu⋆ and roughness length zo of atmospheric surface boundary layer in sparse-tree land

Sparse-tree land is one of the typical lands and can be considered as one typical rough surface in boundary layer meteorology. Many lands can be classified into the kind surface in the view of scale and distribution feature of the roughness elements such as agroforest, scatter planted or growing trees, savanna and so on. The structure of surface boundary layer in sparse-tree land is analyzed and the parameters, friction velocityu⋆and roughness length z_o are deduced based on energy balance law and other physical hypothesis. The models agree well with data of wind tunnel experiments and field measurements. This project is supported by Chinese Academy of Science Responsible editor: Chai Ruihai