In a stratified rotating fluid, frictionally driven circulations couple with the buoyancy field over sloping topography. Analytical and numerical methods are used to quantify the impact of this coupling on the vertical circulation, spindown of geostrophic flows, and the formation of a shelfbreak jet. Over a stratified. slope, linear spindown of a geostrophic along-isobath flow induces cross-iso...

The most-probable states of an equilibrium statistical theory, which consist of monopole vortices, dipole vortex streets, and zonal shear flows for various parameter regimes, are shown to be meta-stable with respect to damped and driven quasigeostrophic dynamics in a periodic β-plane channel. Through a series of numerical experiments that include (1) pure decay, (2) both damping and driving, an...

The impact of the Mongol invasions of the Middle East has been the subject of extensive research, especially in the last few decades. Scholars have evaluated the damage and the benefits brought by the Mongols to the Islamic world in different fields such as the military, religion, politics, economy and culture. Despite this, in the case of Anatolia, the Mongol period is still under-studied when...

Interaction among potential vorticity perturbations and propagating internal gravity waves in a horizontally sheared zonal flow is investigated. In the strong stratification limit, an initial vorticity perturbation weakly excites two propagating gravity waves while the density component of the potential vorticity perturbation is significantly amplified, potentially leading to convective collaps...

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...

A new method of detection and measurement of quantum vorticity by scattering second sound off quantized vortices in superfluid Helium is suggested. Theoretical calculations of the relative amplitude of the scattered second sound waves from a single quantum vortex, a vortex ring, and bulk vorticity are presented. The relevant estimates show that an experimental verification of the method is feas...

In this paper we propose a novel method of adding turbulence to low-res. smoke simulation. We consider the physical properties of such low-res. simulation and add turbulence only to the appropriate position where the value of the energy cascade ratio is judged as physically correct. Our method can prevent noise in the whole region of fluid surfaces which appeared with previous methods. We also ...

Two-dimensional numerical simulations are used to examine the vorticity flux and slot entrance effects in zero-net mass-flux devices. The simulations allow us to extract a simple scaling law for the vorticity flux which provides insight into the relative importance of the various operational parameters. In addition to this, a semi-analytical model is proposed in order to determine the pressure ...

Classes of vortex formation from a horizontal cylinder adjacent to an undulating free-surface wave are characterized using high-image-density particle image velocimetry. Instantaneous representations of the velocity "eld, streamline topology and vorticity patterns yield insight into the origin of unsteady loading of the cylinder. For su$ciently deep submergence of the cylinder, the orbital natu...