ENSO (El Niño–Southern Oscillation) has a large influence on tropical cyclone activity. The authors examine how different environmental factors contribute to this influence, using a genesis potential index developed by Emanuel and Nolan. Four factors contribute to the genesis potential index: low-level vorticity (850 hPa), relative humidity at 600 hPa, the magnitude of vertical wind shear from ...

Potential vorticity (PV) is used as an indicator of the forcing processes and dissipation at work in the Southern Ocean. Output from the Semtner–Chervin model run with quarter-degree resolution is considered on isopycnal surfaces along Montgomery streamfunctions. Numerical results are compared with hydrographic measurements. Although simple hypotheses might suggest that subsurface PV should be ...

The mechanism for the generation of vorticity at a viscous free surface is described This is a free surface analogue of Lighthill s strategy for determining the vorticity ux at solid boundaries In this method the zero shear stress and pressure boundary conditions are transformed into a boundary integral formulation suitable for the velocity vorticity description of the ow A vortex sheet along t...

The mechanism for the generation of vorticity at a viscous free surface is described. This is a free-surface analogue of Lighthill’s strategy for determining the vorticity flux at solid boundaries. In this method the zero-shear-stress and pressure boundary conditions are transformed into a boundary integral formulation suitable for the velocity– vorticity description of the flow. A vortex sheet...

When one splits spacetime into space plus time, the spacetime curvature (Weyl tensor) gets split into an "electric" part E(jk) that describes tidal gravity and a "magnetic" part B(jk) that describes differential dragging of inertial frames. We introduce tools for visualizing B(jk) (frame-drag vortex lines, their vorticity, and vortexes) and E(jk) (tidal tendex lines, their tendicity, and tendex...

We derive the dispersion relation for water waves with surface tension and having a piecewise constant vorticity distribution. More precisely, we consider here two scenarios; the first one is that of a flow with constant non-zero vorticity adjacent to the flat bed while above this layer of vorticity we assume the flow to be irrotational. The second type of flow has a layer of non-vanishing vort...

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...

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 ...

Comment on the paper of Jaffe et al (astro-ph/0503213) on evidence of vorticity and shear of the Universe We show that recent results in the paper of Jaffe et al on evidence of vorticity and shear of the Universe are incorrect. They fit WMAP data with certain Bianchi model which is known to have a vanishing vorticity. The performed fit of the shear is not reliable because the respective formula...