| Abstract: | We study the deformation of the wind velocity profile due to resonant interactions with waves radiated by the flow over a
statistically homogeneous topography. The wind whose velocity vector changes its direction within a layer of finite thickness
is considered. Quasilinear equations for the velocity components of the mean flow are derived under large Richardson, numbers
and small Froude numbers. It is shown that the modulus of the wind velocity is constant in time and its direction angle satisfies
the Riemann equation for simple waves. The flow deformation is determined by the average wave resistance force per unit square.
The deformation of the wind velocity profile takes place within the layer between the Earth’s surface and the level where
the wind change its direction to the opposite one. At large time scales, the wind velocity vector in this layer approaches
the direction opposite to the near-surface one.
Institute of Applied Physics, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika,
Vol. 42, No. 3, pp. 255–265, March 1999. |
