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| | Vorticity and vert motion |
 | | This is shown schematically here, where increasing CVA with height results in a shrinking column. | | | This may not be a flat surface, of course! | | | This parcel (the small circle) has some vorticity value as it enters the trough. |
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http://www.cimms.ou.edu/~doswell/PVAdisc/PVA.html
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| | Vorticity Martial Arts |
| | This site gives information on the martial arts training services provided by Vorticity. | | | Thanks for looking at the Vorticity Martial Arts Web Pages. | | | In this eventuality, it is best if you have some consistent structured training in modern techniques for self-defence. |
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http://www.vorticity-martial-arts.com
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| | Absolute vorticity |
| | horizontal wind shear as it affects the relative vorticity, | | | Figure 1-6-Illustration of shear effect opposing the curvature | | | Therefore, there is no gradient of shear along the |
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http://www.tpub.com/weather1/1i.htm
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| | Interaction of 16 monopoles - not symmetrical / no-slip walls |
| | The colours in the pictures stand for the same vorticity levels throughout the evoltuion shown in the pictures. | | | This dipole is asymmetric, which means that it moves along a curved path. | | | This boundary condition results in the generation of oppositely signed vorticity at the walls. |
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http://www.fluid.tue.nl/users/jos/VDG/mn4-main.html
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| | Navier-Stokes Equations: Vorticity Transport Theorems - Introduction |
| | In the section entitled Shock Waves, the jump in vorticity across a stationary shock wave is presented. | | | The value of the vorticity generated by the shock serves as an initial value for the Vorticity Transport Equation. | | | Thus, it is important to understand the conditions under which the vorticity vanishes. |
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http://www.navier-stokes.net/nsvint.htm
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| | 9: Vorticity |
| | This tends to set up horizontal vorticity, as in the figure. | | | This process tends to smooth out local anomalies of vorticity. | | | An extra term which appears when we describe the evolution of vorticity is a `baroclinic' source term, which generates horizontal vorticity (`overturning') wherever there is a local horizontal density gradient. |
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http://www.env.leeds.ac.uk/envi2210/lectures/lect9.html
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| | Simulation Of Turbulent Flow Using Vortex Particles |
| | With the profile depicted in Figure 4 there are two opposing vorticity strips at each side of the jet. | | | This direct mapping from luminance to vorticity is, of course, arbitrary. | | | This scheme also conserves the total vorticity of the system. |
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http://virtual.inesc.pt/virtual/tr/gamito95/artigo.html
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| | Interpretation of the vorticity equation |
| | This leads to a reduction in the axial moment of inertia of the element and so, by conservation of angular momentum, to an increase in | | | This leads to an intensification of vorticity through conservation of angular momentum, confirming our interpretation of the RHS of Eq. | | | This is because fluid elements are stretched and elongated on the axis, as shown in Fig 7.1. |
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http://astron.berkeley.edu/~jrg/ay202/node93.html
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| | Lecture 5 GETTING IN A SPIN - VORTICITY |
| | This is also no different from the situation due to any horizontal wind shear. | | | This change of vorticity due to north-south motion is called the β-effect, but is nothing more than a different way of expressing conservation of absolute vorticity. | | | This is a very important result because we have seen previously that in the subtropical gyres the wind stress does become more eastward as you move from the trades to the westerlies regime, all across the ocean. |
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http://www.sos.bangor.ac.uk/~oss041/des/o2p03/text/o2p03-05.htm
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| | NWS Detroit/Pontiac -- Area Forecast Discussion Terms |
| | Shear can refer to horizontal shear or vertical shear. | | | There are two types of vorticity; shear vorticity, which arises from changes in wind speed over a horizontal distance, and curvature vorticity, which is due to turning of the wind flow. | | | Negative Vorticity Advection: (NVA) Advection of lower values of vorticity into an area by the wind. |
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http://www.crh.noaa.gov/dtx/afdterms.php
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| | 3: Kinematics; vorticity and divergence |
| | Simplistically, we might say that `shear equals vorticity plus deformation'. | | | Two important quantities which arise are the `vorticity', which might loosely be described as the local rotation of the fluid, and the `divergence', which could be descibed as the local expansion of the fluid. | | | As such, these concepts are very general, and apply to any kind of moving fluid. |
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http://www.env.leeds.ac.uk/envi2210/lectures/lect3.html
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| | The Lamb dipole |
| | This can also be seen in the following pictures. | | | This dipole moves along a staight line with a constant velocity and without change of form. | | | The velocity of the dipole as a whole is the velocity at the extrema of vorticity (which are at y equal 0.48 and -0.48): 1.575, indicated by the blue horizontal line. |
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http://www.fluid.tue.nl/users/jos/VDG/lamb-dip.html
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| | Mid-level shear text |
| | Based on our results, the role of the mid-tropospheric wind shear appears to be indirect | | | The second vorticity maximum moves anticyclonically around the main body of the precipitation region, while a third vorticity region develops on the northeast side of the precipitation. | | | Low-level vorticity (W) in the S = 0.015 s |
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http://www.nssl.noaa.gov/~brooks/midlevel/midlevel.html
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| | Vorticity_primer |
| | Viudez, A., and R.L. Haney, 1996: On the shear and curvature vorticity equations. | | | As shown in Mathematical Diversion - 3, the horizontal vorticity vectors are dominated by the vertical wind shear of the horizontal wind. | | | This happens when the shear term is of the opposite sign to, and is exactly the same magnitude as the curvature term. |
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http://www.cimms.ou.edu/~doswell/vorticity/vorticity_primer.html
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| | CALCULATION OF EARTH, SHEAR AND CURVATURE VORTICITY |
| | Therefore, the value of curvature vorticity is 0.1745/3,600 = 4.8*10^-5/s. | | | This model is showing absolute vorticity, which is earth, shear and curvature vorticity combined together. | | | This produces about 5 units of positive curvature vorticity. |
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http://www.theweatherprediction.com/habyhints/194
(695 words)
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| | Vorticity - Wikipedia, the free encyclopedia |
| | This page was last modified 09:25, 10 March 2006. | | | This can be seen by the diffusion term in the vorticity transport equation. | | | Related concepts are the vortex-line, which is a line which is everywhere tangent to the local vorticity; and a vortex tube which is the surface in the fluid formed by all vortex-lines passing through a given (reducible) closed curve in the fluid. |
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http://en.wikipedia.org/wiki/Vorticity
(1295 words)
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| | ESCI 445 - Numerical Modeling of the Atmosphere and Oceans |
| | This is why vorticity is so useful in meteorology. | | | This equation is a conservation law for absolute vorticity, and says that absolute vorticity can only change due to divergence or convergence of the ageostrophic wind. | | | Vorticity can be expressed in terms of streamfunction via |
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http://snowball.millersville.edu/~adecaria/ESCI445/esci445_02_Dynamics_II.html
(1260 words)
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| | Atmospheric Kinematics: Rotation and Vorticity |
| | This shear in the 'translation' field produces both a cyclonic and anticyclonic rotation in the flow. | | | However, the curvature of a streamline and that of a trajectory will generally be different values. | | | This shear vorticity appears whenever there is change in wind speed laterally across the flow and can be expressed as |
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http://www.rwic.und.edu/~leono/academics/AtSci320/Lectures/Sept1797/LectureSept17Vorticity.html
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| | VORTICITY BASICS |
| | Vorticity caused by a change in wind direction or wind speed with height is termed horizontal vorticity (the spin is in relation to a horizontal axis). | | | In summary, vertical positive vorticity contributes to upper level divergence in the PVA region and thus rising air while horizontal vorticity is important to severe weather (large values of horizontal vorticity lead to large values of Helicity, which increases the likelihood of tornadoes in association with supercell thunderstorms). | | | Streamwise vorticity is the amount of horizontal vorticity that is parallel to storm inflow. |
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http://www.theweatherprediction.com/habyhints/56
(297 words)
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| | Unit 3. Synoptic-Scale Systems |
| | This is due to the addition of positive curvature vorticity. | | | This spin is caused by wind shear and contour curvature. | | | This can be proven mathematically by using the vorticity theorem, but this is beyond the scope of this text. |
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http://www.fas.org/spp/military/docops/afwa/atmos-U3.htm
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| | VORTICITY |
| | Figure 1-4.-Illustration of vorticity due to the shear effect. | | | The vorticity of a horizontal current can be broken down | | | Vorticity can also result due to curvature of the |
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http://www.tpub.com/content/aerographer/14010/css/14010_18.htm
(514 words)
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| | Vorticity Music |
| | 2004 Copyright Vorticity Music Pty Ltd ABN - 083 347 0312003 | | | Vorticity Music produces and distributes CDs, Videos, Magazines and DVDs with free delivery internationally. | | | Vorticity Music Presents Mark Isaacs Latest CD Visions |
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http://www.vorticitymusic.com
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| | Navier-Stokes Equations: Vorticity Jump Across Shock Waves |
| | This result follows directly from the fact that the velocity components parallel to the shock are continuous, i.e., (48). | | | However, for a three-dimensional shock in a uniform flow, the curvature of the shock is usually of the order of the shock strength, so that the both the entropy and the vorticity generated by the shock are of third-order in the shock strength. | | | This extremely simple result reveals that the vorticity generated by a shock wave depends on the density ratio across the shock, the uniform upstream velocity U, and the shape of the shock through n and B. |
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http://www.navier-stokes.net/nsvsj.htm
(695 words)
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| | Kelvin's vorticity theorem for incompressible or barotropic flow |
| | This could have been deduced from the vorticity equation itself. | | | after some time then Kelvin's theorem states that the vortices also move with the fluid to the neighborhood of | | | , Kelvin's theorem follows as a special case of this general theorem, implying that the flux of vorticity is conserved and the vortex lines move with the fluid. |
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http://astron.berkeley.edu/~jrg/ay202/node94.html
(395 words)
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| | Vorticity equation - Wikipedia, the free encyclopedia |
| | This page was last modified 03:23, 29 April 2005. | | | It describes the total derivative (that is, the local change due to local change with time and advection) of vorticity, and thus can be stated in either relative or absolute form. | | | The terms on the RHS denote the positive or negative generation of absolute vorticity by divergence of air, twisting of the axis of rotation, and baroclinity, respectively. |
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http://en.wikipedia.org/wiki/Vorticity_equation
(135 words)
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| | "Dynamics" Means More Than "Vorticity Advection" |
| | The assumption is often made that the vorticity advection at the ground is zero, in which case vorticity advection at 700 or 500 mb can be used to assess the first term. | | | The parent equations that can be used to understand this are all variations of the same theme. | | | This shows the vorticity advection at the 1000 mb level and the 700 mb level. |
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http://home.earthlink.net/~montever/warmadv/qg.html
(1040 words)
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| | NUMERICAL PARAMETERS FOR SYNOPTIC- TO MESOSCALE CLOUD SYSTEMS: Vorticity Advection |
| | This image shows vorticity and the positive part of vorticity advection which is the important contribution for upward motion. | | | This can very clearly be seen near the PVA maximum close to Cornwall which is in front of a less anticyclonic area; although according to the mathematical relation these PVA maxima should also contribute to upward motion, to date no practical use could be derived from them. | | | There are several PVA maxima over the Atlantic south of the frontal cloud bands (approximately south of 50N); they appear in the anticyclonic part of vorticity and mark areas where vorticity becomes less anticyclonic. |
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http://www.zamg.ac.at/docu/Manual/SatManu/Basic/Parameters/PVA.htm
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| | Navier-Stokes Equations: Cauchy's Integral and the Distortion of Vorticity |
| | Consider a set of material particles for which the vorticity is zero and the entropy is uniform. | | | I'll begin by restricting attention to flows which are inviscid and for which the vorticity generation mechanisms are zero. | | | As mentioned in the introduction to our discussion of vorticity the second motivation for the study of vorticity is that its dynamics play a key role in many applications. |
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http://www.navier-stokes.net/nsvci.htm
(918 words)
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| | Shed Vortex |
| | For a general shaped airfoil, there is some distribution of vorticity which we can think of as small vortices. | | | It took some very careful experimental work by Ludwig Prandtl to actually "catch" the other vortex on film. | | | The flow turning creates a downwash from the wing which can be observed in flight. |
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http://www.grc.nasa.gov/WWW/K-12/airplane/shed.html
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| | Penn State Meteo 200 (201): LESSON 7 SUPPLEMENT |
| | Relative vorticity is non-zero for two reasons: either the streamlines of the wind have curvature or the wind field has horizontal shear, or both. | | | This is significant because the main mechanism that the atmosphere has to reduce vorticity is divergence. | | | This is significant because the main mechanism that the atmosphere has to increase vorticity is convergence. |
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http://www.ems.psu.edu/Courses/Meteo200/lesson7/wxfcstg.htm
(1871 words)
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| | Stretching of a vortical structure: filaments of vorticity1 |
| | This gives a zero vorticity outside this region. | | | This calculation has been performed after a Gaussian-type filtering of the velocity field of Figure 5a. | | | A large part of the scientific community working on turbulence believes that these structures are very important in the dynamics of turbulent flows, although their structure, their dynamics or their instabilities are not fully understood. |
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http://www.europhysicsnews.com/full/19/article5/article5.html
(2753 words)
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| | Potential Vorticity Distribution |
| | Potential vorticity has been shown to be useful in studies of large-scale ocean circulation. | | | Conductivity-Temperature-Depth (CTD) data were obtained along CALCOFI Line 67 from a survey conducted by the R/V Point Sur during the period 4-8 December 2000. | | | Contours of potential vorticity (Figure 8, plotted down to 300 dbar) depict several features worthy of discussion. |
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http://www.weather.nps.navy.mil/~psguest/OC3570/CDROM/winter2001/Ruth/report.htm
(1545 words)
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| | Potential Vorticity |
| | The Indian Ocean work is currently in press at J. Geophys. | | | Particular attention has been paid to determining which regions are strongly influenced by the mid-laitude gyre circulations compared with the tropical regions, surface convection (mode water/intermediate water/deep water formation areas), and to the vertical extent of topographic influence. | | | This change in the nature of the PV field between the tropics and subtropics likely affects planetary wave propagation characteristics. |
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http://sam.ucsd.edu/papers/WOCE_potvor_abs.html
(880 words)
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| | Stream-function Vorticity Equations |
| | This means that the normal derivative of the stream-function is not imposed, but rather obtained as part of the solution. | | | Currently, we are working on methods to satisfy the no-slip boundary condition. | | | Finite volume methods for solving the stream-function vorticity equations in irregular regions |
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http://www.cims.nyu.edu/~calhoun/vorticity_patch.html
(206 words)
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| | Reanalysis Plotter - Isentropic Potential Vorticity |
| | Isentropic potential vorticity is available directly from the NCEP/NCAR 40-Year Reanalysis CD-ROM on theta surfaces of 315 K, 330 K, and 450 K. Observations are made at 00Z. | | | First, note that the values have been multiplied by 1*10 | | | The NCEP PV is still a form of the Ertel potential vorticity, since log(theta) is as well conserved as theta. |
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http://weather.ou.edu/~cgodfrey/reanalysis/pv.html
(305 words)
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| | Vorticity |
| | relative vorticity: sum of curvature and shear (sum of the curving of the airflow and the changing of the wind speed over a horizontal distance. | | | absolute vorticity: sun of the earth’s vorticity and the relative vorticity | | | because of the earth’s vorticity in the middle and high latitudes is great enough to make a parcel’s spin cyclonic any where on earth. |
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http://www.cord.edu/faculty/ritchiso/exam4/tsld022.htm
(114 words)
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| | Propagation of a tropical cyclone in meridionally-varying zonal flows: An energetics analysis Abstract |
| | Ulrich and Smith (1991), and Smith (1991) examined the effect of zonal environmental flows with constant shear on vortex motion on a beta-plane. | | | As a result, the gyres are stronger and the beta-drift is faster near the subtropical ridge than within a monsoon trough. | | | The kinetic energy equations of the gyres will be first derived in the next section. |
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http://www.soest.hawaii.edu/MET/Faculty/bwang/bw/pubs/38.html
(1586 words)
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| | Vorticity |
| | The major difference between the two last operators is that the Richardson extrapolation is designed to produce a smaller truncation error, while the least squares operator reduces the effect of fluctuations. | | | If no output argument is included, a figure window will appear showing the result. | | | We start by exploiting the possibility of extracting the vorticity from our 2-D measurement. |
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http://www.math.uio.no/~jks/matpiv/html/node31.html
(214 words)
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| | 2003: JAS, 60(8), 1024-1040 |
| | Functional forms of the surface potential vorticity are derived from field equations in which the potential vorticity and a potential vorticity flux appear as sources of flow quantities in the same way in which an electric charge and an electric current appear as sources of fields in electrodynamics. | | | A nongeostrophic effect described by the conservation law is the induction of generalized potential vorticity by baroclinicity at boundaries, an effect that plays a role, for example, in mesoscale flows past topographic obstacles. | | | For the generalized potential vorticity of flows that need be neither balanced nor hydrostatic and that can be influenced by diabatic processes and friction, a conservation law holds that is similar to the conservation law for the conventional interior potential vorticity. |
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http://www.gfdl.noaa.gov/~ih/abstracts/78.html
(305 words)
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| | Unstable Vorticity Rings |
| | If narrow enough, such vorticity rings can be very unstable. | | | Which end state is observed depends on initial conditions such as ring diameter and ring width. | | | The end states of such instability can be of three types: (1) a vorticity monopole (i.e., high vorticity in the center); (2) a vortex crystal pattern (i.e., several mesovortices locked in rigid rotation); (3) a chaotic pattern of mesovortices. |
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http://euler.atmos.colostate.edu/~vigh/vorticity
(193 words)
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| | Observations of Vorticity Near Shore |
| | The area closer to shore (again much more noisy and less reliable) appears to have a shorter time scale than the offshore area, but longer than on 10/14: of order two-thirds the offshore value. | | | As indicated, the conditions were pretty calm during this period, with winds under 2 m/s and waves around 0.5 m significant height. | | | Such convergent fronts were observed fairly often over the two-month deployment; during the moderately stormy period around 10/18, they sometimes occurred several times per hour. |
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http://jerry.ucsd.edu/ObsofVorticity.html
(1014 words)
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| | Potential vorticity and isentropic charts |
| | Note that the units of units of PV are not the same as those of other vorticity variables. | | | A combination of the momentum conservation equation and first law of thermodynamics shows that the potential vorticity can only be changed by diabatic heating or friction. | | | When a spinning ice skater has her arms spread out laterally, she spins slowly. |
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http://www-das.uwyo.edu/~geerts/cwx/notes/chap12/pot_vort.html
(912 words)
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| | Articles ``Balanced Flow'' and ``Potential Vorticity'' for the new Encyclopedia of Atmospheric Sciences |
| | The Potential Vorticity article has two accompanying figures, and also mentions figures from Professor Holton's introduction/overview (not available here), referring to page numbers in the Encyclopedia to be supplied by the copy editors. | | | Estimated isentropic distribution of Rossby-Ertel PV on the 320K isentropic surface on 14 May 1992 at 1200 UT (Greenwich mean time), derived from observations as explained in the text. | | | The text of the article on Potential Vorticity (vol 2, pp. |
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http://www.atm.damtp.cam.ac.uk/mcintyre/papers/ENCYC
(604 words)
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| | Ross Bannister's Home Page - Barotropic Vorticity Equation |
| | Output 2: The vorticity (frame time 2 hours) | | | Amongst the first successful attempts to model the atmosphere numerically was that of Charney, Fjorloft and von Neumann (1950) who integrated the barotropic vorticity equation (BVT) forward in time (the BVT is shown below with added second order difusion). | | | Various quantities are output including the stream function (below - this is essentially the geopotential height - and hence can also be thought of as 'pressure-like') and the vorticity. |
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http://www.met.rdg.ac.uk/~ross/BarVor.html
(266 words)
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| | Vorticity - Politics, Religion and Other Impolite Topics |
| | Vorticity - Politics, Religion and Other Impolite Topics | | | The decline of Europe and the increasing incursion of Islam into Western countries is a primary reason why the President is trying to establish a beach head of democracy in the Middle East. | | | Search for words used in entries on this website |
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http://www.sebourn.com/WebLog
(3980 words)
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| | Vorticity Advection: leads to rising/falling pressures at the surface |
| | The advection of vorticity at high levels will result in a response at the surface which will attempt to offset the effects of the advection. | | | Notice how the surface low has deepened in the area of strong vorticity advection. | | | Air that rotates counterclockwise, such as in cyclones and troughs, is said to have positive vorticity. |
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http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/af/adv/vadv.rxml
(131 words)
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| | Gothamist Weather: Vorticity, vorticity, vorticity. Does that word do anything for you? |
| | Short waves occasionally travel through the long waves. | | | Most TV weatherpeople are forbidden from saying "vorticity" but Gothamist trusts our reader's intelligence. | | | The movement of vorticity is related to air diverging, or spreading out, higher up in the atmosphere. |
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http://www.gothamist.com/weather/archives/2004/07/13/vorticity_vorticity_vorticity_does_that_word_do_anything_for_you.php
(333 words)
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| | AMS Glossary |
| | The vorticity component normal to a small plane element is the limit of the circulation per unit area as the area of the element approaches zero (see Stokes's theorem). | | | See also relative vorticity, absolute vorticity, geostrophic vorticity, thermal vorticity, vorticity equation, curl; compare deformation, divergence. | | | In meteorology, “the vorticity” usually refers to the vertical component of the vorticity. |
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http://amsglossary.allenpress.com/glossary/search?p=1&query=vorticity&submit=Search
(128 words)
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| | Definition of Relative Vorticity |
| | If the parcel were initially moving southwestward, how would it's direction change, if at all? | | | What would happen to the absolute vorticity of a moving air parcel? | | | The sum of a parcel's planetary vorticity and it's relative vorticity is called |
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http://apollo.lsc.vsc.edu/classes/met130/notes/chapter13/relative_vorticity.html
(77 words)
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Topic: Vorticity