On the Structure of Wind near the Ground (V)

[摘要] In order to explain the connection between the horizontal and vertical structures of wind, the concept of the coupling eddy is postulated. The coupling eddy in the vertical structure is coincident with the vertical largest eddy. The movements of the coupling eddy in the horizontal and vertical directions are thought to be completely correlated with each other, and the correlation coefficient between two velocities u* and w* of the coupling eddy is assumed to be given by the following relationThe turbulent velocities u and w which are observed in the wind contain not only the components of coupling eddy but also many components of eddies of other ranks, The correlation coefficient Ruw between u and w can be related with Ru*w*.For the natural wind, the effective largest eddy in horizontal plane usually increases its scale simultaneously with the increase in the time duration T of observation. Thus, as the time duration is prolonged, Ruw decreases in the following relationThis relation is examined by the practical observation.

[学科分类] 大气科学