Barotrope

In Mechanical of the fluids, a fluid barotrope , is that whose lines of equal Pression are parallel with those of equal Densité ( isopycne ). This qualifier is used in several fields of which the Météorologie, the physical Océanographie and the Astrophysique to describe gases or liquids of which propriétées do not vary with the thickness.

Consequences

In an ideal fluid barotrope, the variation of the pressure is done only with the variation of the density: \, P = P (\ rho) \ propto P (T) . This wants to say:

  • that the Température (T) is everywhere equal to a pressure level (P)

  • that a flow with a given pressure level does not change the temperature on this level. It is thus strongly constrained
  • that a disturbance barotrope is a disturbance in flow coming from the horizontal shearing of the basic flow, and not of the conversion of the potential energy into kinetic energy

The image of right-hand side shows the vertical stratification of the density and the pressure. Notice that one gave a slope to these lines. If one made a cut according to the horizontal one, one would see that the pressure changes when one goes from has to B, in the same way that the density. It is what one observes in a chart on constant level, like a chart of surface of the weather systems, when it is seen that the Isobare S are parallel to the Isotherme S.

Uses

See also: Theory of the figures of balance

  • thermal Wind: the wind is a balance between the Force of Coriolis and that of the pressure. The latter varies according to hydrostatic balance with the density of the air according to the height and thus with the average temperature of the layer. As the temperature does not vary with telling pressure level, the wind cannot vary with altitude in an atmosphere barotrope and one obtains a thermal wind no one.
  • numerical Forecast of time: the first digital models to solve the behavior of the atmoshpère used like assumption an atmosphere barotrope to simplify the mathematical formulation and calculations. These models were with two dimensions and did not take account of the horizontal variations in temperature, nor of vertical shearings of the wind. They provided a forecast on only one level (often 500 hPa). One still uses aujourdui this kind of models in particular simulations.
  • Oceanography: for the modeling of the current sailors, Thermocline, Astrophysical etc
  • : the fluids barotropes are important in the study of the ideal fluids of stars and interstellar environments.
  • Geophysical: the concept is important in the study of the magma under the earth's crust.

Random links:Not prolongation | Flight 401 Eastern Air Lines | National parks of Cameroun | Jürgen Rosenthal | Viandox | 1982_titulaires_canadiens