isobar
C2Formal, Technical, Academic
Definition
Meaning
A line on a weather map connecting points with equal atmospheric pressure.
In meteorology and physics, it denotes a curve or line on a graph connecting points of equal pressure, typically at a given time or averaged over a period. In nuclear physics, it can refer to one of two or more nuclides with different atomic numbers but the same mass number.
Linguistics
Semantic Notes
The primary meaning is meteorological. The nuclear physics meaning is highly specialised and less frequent. In general discourse, it is almost exclusively a technical term.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling and pronunciation are consistent.
Connotations
Neutral, purely scientific/technical in both varieties.
Frequency
Equally low-frequency and specialised in both UK and US English, confined to weather forecasts, scientific reports, and educational contexts.
Vocabulary
Collocations
Grammar
Valency Patterns
The isobar [connects/indicates/shows]...[Closely-spaced/Widely-spaced] isobars [suggest/mean]...An isobar of [1013 hPa]...[Plot/Draw/Analyse] the isobars.Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “None. Too technical for idiomatic use.”
Usage
Context Usage
Business
Virtually unused, except in specific industries like renewable energy (wind farming) or logistics affected by weather.
Academic
Used in geography, environmental science, meteorology, and physics courses and publications.
Everyday
Rare. Might be encountered in detailed weather forecasts or documentaries.
Technical
The primary domain of use. Essential terminology in meteorology, climatology, and nuclear physics.
Examples
By Part of Speech
verb
British English
- Meteorologists will isobar the chart to analyse the depression.
American English
- The software automatically isobars the pressure data for the forecast model.
adverb
British English
- The pressure was distributed isobarically across the region.
American English
- The data was plotted isobarically for clarity.
adjective
British English
- The isobar analysis revealed a steep pressure gradient.
American English
- They studied the isobar map to predict storm intensity.
Examples
By CEFR Level
- Look at the weather map. The lines are called isobars.
- Closely spaced isobars on the chart indicate strong winds are likely.
- The analysis involved interpolating surface pressure readings to draw accurate isobars, revealing a complex frontal system.
Learning
Memory Aids
Mnemonic
Think: 'ISO' means equal (like in 'isosceles' triangle) + 'BAR' relates to barometric pressure. An ISOBAR connects places with equal pressure.
Conceptual Metaphor
A contour line of force (pressure). A map of invisible atmospheric 'height' or 'weight'.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid confusing with 'изобара' (direct cognate, same meaning). The trap is assuming the word is common in everyday English; it is highly technical.
Common Mistakes
- Mispronouncing as 'eye-so-bar' (/'aɪ.soʊ.bɑːr/) instead of the standard /'aɪ.sə.bɑːr/. Confusing with 'isotherm' (equal temperature) or 'isohyet' (equal rainfall). Using it as a general term for any line on a map.
Practice
Quiz
In which field would you LEAST likely encounter the term 'isobar'?
FAQ
Frequently Asked Questions
They indicate a steep pressure gradient, which typically results in stronger winds.
Yes, but rarely. In nuclear physics, it refers to nuclides with the same mass number but different proton numbers.
A contour line connects points of equal height or elevation. An isobar connects points of equal atmospheric pressure. Both are types of isolines.
It would sound very technical. In everyday talk about weather, people would simply say 'the pressure lines on the weather map'.