An isobar is a line of equal or constant pressure on a graph, plot, or map; an isopleth of pressure. In meteorology, the pressures shown are reduced to sea level, not the surface pressures at the map locations. The distribution of isobars is closely related to the magnitude and direction of the wind field, and can be used to predict future weather patterns.

Also, in nuclear physics, two nuclides with the same mass number are called isobars. For example, boron-12 and carbon-12 are isobars.

Isobar has also occasionally been used as a synonym for a heat pipe.

The word derives from the two ancient Greek words, ισος (isos), meaning 'equal', and βαρος (baros), meaning 'weight'.

See also

• Isosurface
• Isobaric process

Two varieties of the same element of different atomic masses are isotopes, not isobars. A nuclide in an excited state (i.e., containing more energy, but with no change in number of protons and neutrons) is an nuclear isomer.

External links

• National Science Digital Library - Isobar
• Drawing Contour Plots. A lesson plan that deals with drawing various isopleths including isobars.

Basic meteorological concepts and phenomena | Nuclear physics

Изобар (линия) | Isobar | Isobare | Isobara | Isobare (thermodynamique) | Isóbara | Isobara | Izobara | Изобары | Izobara | Isobaari | Isobar | Ізобара