Abstract. Global reanalyses from data assimilation systems are among the most widely used datasets in weather and climate studies, potential vorticity (PV) is invaluable for many studies of dynamical transport processes. We assess how consistently modern represent each other, focusing not only on PV but also process-oriented diagnostics including equivalent latitude calculated PV-based tropopau...

We study the BV-α-Deconvolution model. It is a family of regularizations of the Barotropic Vorticity (BV) model that generalize the BV-α model and improve its accuracy. A both unconditionally stable and optimally convergent scheme for the BV-α-Deconvolution model is proposed and we show that it is O(α), where N is the deconvolution order, whereas the BV-α model is at most second order accurate....

Rivers empty into oceans and lakes as turbulent sediment-laden jets, which can be characterized by a Gaussian horizontal velocity profile that spreads and decays downstream because of shearing and lateral mixing at the jet margins. Recent experiments demonstrate that this velocity field controls river-mouth sedimentation patterns. In nature, diffuse jets are associated with mouth bar deposition...

For the past several years, there has been a lot of work in modelling complex simulations pertaining to motion of gases. In the work of [Fedkiw et al., 2001], a new approach to numerically simulate smoke was developed which incorporates the model proposed by Steinhoff and Underhill [Steinhoff and Underhill, 1994] known as “vorticity confinement”. Passive advection of smoke particles is consider...

Abstract   The present paper is devoted to implementation of the immersed boundary technique into the Fourier pseudo-spectral solution of the vorticity-velocity formulation of the two-dimensional incompressible Navier-Stokes equations. The immersed boundary conditions are implemented via direct modification of the convection and diffusion terms, and therefore, in contrast to some other similar ...

The downstream evolution of the vorticity field in the vicinity of hairpinshaped regions of rotational motion appearing in the transitioning boundary layer is examined. It is shown that the dynamics of hairpins is inseparable from that of the non-rotational vorticity out of which they develop in a self-reinforcing process of ejection and reorientation. Widening the concept of structure to inclu...

which implies that the topology of the vorticity vector field must be very simple. Even local existence of the Clebsch representation is only guaranteed at points where the vorticity does not vanish. It has been shown (Graham-Henyey [17]) that in general (1.3) can not hold around a point with zero vorticity. For more discussion on the properties of classical Clebsch variables and its various ge...

An initial value approach is used to examine the dynamics of perturbations introduced into a vortex under strain. Both the basic vortex considered and the perturbations are taken as fully three-dimensional. An explicit solution for the time evolution of the vorticity perturbations is given for arbitrary initial vorticity. Analytical solutions for the resulting velocity components are found when...

Thewake flow behind two yawed side-by-sidecircular cylinders is investigated using athree-dimensional vorticity probe. Four yaw angles (α), namely, 0°, 15°, 30° and 45° and twocylinder spacing ratios T of 1.7 and 3.0 were tested. For T = 3.0, there exist two vortex streets and the cylinders behave as independent and isolated ones. The maximum contour value of the coherent streamwise vorticity *...

introduction occurrence of heavy and rainstorm events is among the characteristics of arid and semi-arid regions all over the world and particularly in iran which is causing large floods and debris town. how ever, they can be used to supply and store water by controlling and exploiting the run off water floods. indexes of atmospheric instability are very useful scientific instruments to underst...