isobar

American  

[ahy-suh-bahr] / ˈaɪ səˌbɑr /

noun

1. Meteorology. a line drawn on a weather map or chart that connects points at which the barometric pressure is the same.

2. Physics, Chemistry. Also isobare one of two or more atoms having equal atomic weights but different atomic numbers.

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isobar British  

/ ˈaɪsəʊˌbɑː /

noun

1. a line on a map connecting places of equal atmospheric pressure, usually reduced to sea level for purposes of comparison, at a given time or period

2. physics any of two or more atoms that have the same mass number but different atomic numbers Compare isotope

   tin-115 and indium-115 are isobars

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isobar Scientific  

/ ī′sə-bär′ /

1. A line drawn on a weather map connecting places having the same atmospheric pressure. The distance between isobars indicates the barometric gradient (the degree of change in atmospheric pressure) across the region shown on the map. When the lines are close together, a strong pressure gradient is indicated, creating conditions for strong winds. When the lines are far apart, a weak pressure gradient is indicated and calm weather is forecast.

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Other Word Forms

• isobarism noun

Etymology

Origin of isobar

First recorded in 1860–65; from Greek isobarḗs “of equal weight,” from ísos ( iso- ( def. ) ) + báros “weight” ( bar ³ ( def. ) )

Example Sentences

Do you know your cold fronts from your isobars?

From BBC

When isobars — lines of constant pressure — are packed tightly together, and move into the D.C. region rapidly, this leads to a strong pressure surge, generating powerful wind gusts.

From Washington Post

Its pressure isobars are spaced far apart; there is little wind speed.

From New York Times

When we ran out of ways to tart up the lowly isobar, we went off-planet.

From Washington Post

He was recognised for his Scottish accent and known for his exuberance and ceaseless enthusiasm for anticyclones, warm fronts and isobars during his career.

From BBC