Baroclinia

Crossing the levels of isobaras with the same density (isopicnas) in the vertical, or temperature in the horizontal

In fluid dynamics, the baroclinity (often called the barocline) of a layered fluid is a measure of how misaligned the pressure gradient is with respect to the gradient. of density of a fluid. In meteorology, a baroclinic atmosphere is one whose density depends on both temperature and pressure; compare with a barotropic atmosphere, the density of which depends only on pressure. In atmospheric terms, Earth's barotropic zones are generally found in the central latitudes, or tropics, while baroclinic zones are generally found in the midlatitude/polar regions.

Baroclinity is proportional:

► ► p× × ► ► ρ ρ {displaystyle nabla ptimes nabla rho }

which is proportional to the sine of the angle between the surfaces of constant pressure and the surfaces of constant density. Thus, in a barotropic fluid (which is defined by zero baroclinity), these surfaces are parallel.

Zones with high atmospheric baroclinity are characterized by the frequent formation of cyclones.