The formation of orographic wakes and vortices is studied within the context of numerically simulated viscous flow with uniform basic-state wind and stability past elongated free-slip ridges. The viscosity and thermal diffusivity are sufficiently large that the onset of small-scale turbulence is suppressed. It is found in Part I of this study that wake formation in the viscous flow is closely t...

The effects of an oscillatory zero-net-mass-flux jet (i.e. synthetic jet) acting on a separated flow over a hump are investigated in terms of two actuation parameters – actuator position and forcing frequency. By considering the vorticity flux balance and introducing a centroid of vorticity production over the hump surface, lift and drag acting on the hump can be expressed as a function of this...

A key feature of three-dimensional fluid turbulence is the stretching and realignment of vorticity by the action of the strain rate. It is shown in this paper, using the cumulant-generating function, that the cumulative vorticity stretching along a Lagrangian path in isotropic turbulence obeys a large deviation principle. As a result, the relevant statistics can be described by the vorticity st...

dehbid mylonite nappes associated with the tutak gneiss dome as the zagros hinterland involved-basement window in the zagros orogenic belt has significant components of dextral sense of shear along the mylonite nappes and are related to the high proportion of simple shear relative to pure shear deformation. kinematic vorticity analysis (wk) was made in order to determination of relative amounts...

An ocean general circulation model of the tropical Atlantic Ocean is used to study the vertically integrated vorticity equation for the annual mean flow in the Atlantic North Equatorial Countercurrent (NECC). It is found that the nonlinear terms play an important role in the vorticity budget, in the western part of the basin. Sverdrup balance does not hold in the region of the North Brazil Curr...

By performing estimates on the integral of the absolute value of vorticity along a local vortex line segment, we establish a relatively sharp dynamic growth estimate of maximum vorticity under some assumptions on the local geometric regularity of the vorticity vector. Our analysis applies to both the 3D incompressible Euler equations and the surface quasi-geostrophic model (SQG). As an applicat...

An exact complex mapping is used to show the close relationship between the Schroedinger equation for a charged particle in an external ̄eld, the Landau-Ginsburg equation for the order parameter in a superconductor, and the equation for the evolution of vorticity in a Navier-Stokes compressible, viscous, °uid. The absolute square of the wave function, or complex order paramter, is exactly equal...

The persistence of the North Atlantic Oscillation (NAO) is studied using observations of the threedimensional vorticity budget in the Atlantic sector. Analysis of the relative vorticity tendency equation shows that convergence of eddy vorticity flux in the upper troposphere counteracts the effect of anomalous largescale divergence at the upper level. At low levels, the convergence associated wi...

This study uses a shallow-water, normal-mode spectral model to examine the non-linear potential vorticity (PV) dynamics of the break¬down of both infinite an finite-length initial vorticity strips, simulating the inter-tropical convergence zone (ITCZ) found near the tropical eastern Pacific region. Irregularities in convection and diabatic heating are simulated using uniformly and randomly spac...