Self-protection and self-similarity of the stably-stratified geophysical turbulence Conference Paper uri icon

abstract

  • Abstract Following Richardson (1920), the effect of stratification on the shear-generated geophysical turbulence is determined by the gradient Richardson number Ri=(N/S) 2, where Nis the Brunt-Vaisala frequency, S= dU/dz is vertical shear of the mean wind/current velocity U, and z is vertical coordinate. The concept of Richardson-number similarity postulates that dimensionless characteristics of turbulence are universal functions of Ri. Monin and Obukhov (1954) have proposed for the atmospheric surface layer a widely recognised Monin-Obukhov similarity theory (MOST). This theory postulates that dimensionless characteristics of turbulence are fully determined by the ratio z/L, where L=-u* 3/Fb is the Obukhov length scale, u* is friction velocity and Fb is vertical turbulent flux of buoyancy. Nieuwstadt (1984) has employed local, z-dependent values of Fb and u* instead of the …

publication date

  • January 1, 2014