A theory for the transport of a tracer in flow dominated by turbulence and jets is developed and tested. Such a system can be taken as a model either for the stirring of true tracers in the atmosphere and ocean, or, less obviously, for the stirring of baroclinic potential vorticity by non-zonal flow in the ocean. The flow is generated by two-dimensional turbulence with a mean vorticity gradient...

A partition of the geostrophic vorticity into shear and curvature components is employed to consider the influence of differential vorticity advection on the development of upper level jet-front systems in northwesterly flow in an idealized and an observed case. The analysis reveals that negative geostrophic shear vorticity advection by the thermal wind, inextricably coincident with regions of ...

A new approach to consider balance dynamics for modelling slow vortical motion is suggested within the rotating shallow water primitive equations. Instead of a traditional approach using divergence and ageostrophic vorticity as fast variables, the velocity is exactly expressed as a sum of the gradient part, described by a Bernoulli function, and the rest, an agradient part, proportional to the ...

A50-m-grid-spacingAdvancedRegional Prediction System (ARPS) simulation of the 8May 2003Oklahoma City tornadic supercell is examined.A 40-min forecast run on the 50-m grid produces twoF3-intensity tornadoes that track within 10km of the location of the observed long-track F4-intensity tornado. The development of both simulated tornadoes is analyzed to determine the processes responsible for torn...

We introduce a new finite element method for the approximation of the three-dimensional Brinkman problem formulated in terms of the velocity, vorticity, and pressure fields. The proposed strategy exhibits the advantage that, at the continuous level, a complete decoupling of vorticity and pressure can be established under the assumption of sufficient regularity. The velocity is then obtained as ...

Local and nonlocal contributions to the total strain rate tensor S(ij) at any point x in a flow are formulated from an expansion of the vorticity field in a local spherical neighborhood of radius R centered on x. The resulting exact expression allows the nonlocal (background) strain rate tensor S(ij)(B)(x) to be obtained from S(ij)(x). In turbulent flows, where the vorticity naturally concentra...

Traditional electrostatic gyrokinetic treatments consist of a gyrokinetic Fokker-Planck equation and a gyrokinetic quasineutrality equation. Both of these equations can be found up to second order in a gyroradius over macroscopic length expansion in some simplified cases, but the versions implemented in codes are typically only first order. In axisymmetric configurations such as the tokamak, th...

The question of vortex growth in Euler flows leads naturally to the emergence of paired vortex structure and the “geometric” stretching of vortex lines. In the present paper, the first of two papers devoted to this question, we examine bounds on the growth of vorticity in axisymmetric flow without swirl. We show that the known bound on vorticity in this case, exponential in time, can be improve...

The nature of vorticity transport in three-dimensional turbulent flow is investigated using data from a direct numerical simulation of channel flow. An extension of Taylor's (1932) vorticity transport theory is derived by a formal Lagrangian analysis in which care is taken to include nongradient transport effects associated with vortex stretching and shearing. A comparison is made between the p...

In this paper potential vorticity (PV) and potential vorticity inversion (PVI) and their application in the cyclogenesis and mesoscale meteorological phenomena are reviewed. PV has been served as a powerful and useful dynamic tracer for the understanding of the large-scale dynamics and synoptic variations in the atmosphere and oceans. Significant progress has been made on the application of PV ...