sea-level pressure: meaning, definition, pronunciation and examples
C1Technical / Scientific
Quick answer
What does “sea-level pressure” mean?
The atmospheric pressure at mean sea level, used as a standard reference point in meteorology.
Audio
Pronunciation
Definition
Meaning and Definition
The atmospheric pressure at mean sea level, used as a standard reference point in meteorology.
A standardized measure of atmospheric pressure, calculated by adjusting the observed pressure at a given location to what it would be if that location were at sea level, allowing for comparison across different elevations.
Dialectal Variation
British vs American Usage
Differences
No significant lexical differences. Spelling follows regional conventions for 'level' in compounds (no difference). The term is used identically in meteorological contexts.
Connotations
Purely technical and scientific in both varieties.
Frequency
Equally frequent in technical weather reports and academic meteorology in both the UK and US. Virtually absent in everyday conversation.
Grammar
How to Use “sea-level pressure” in a Sentence
The [noun] showed a sea-level pressure of [value].Meteorologists reduced the station pressure to sea-level pressure.A centre of low/high sea-level pressure developed over the region.Vocabulary
Collocations
Examples
Examples of “sea-level pressure” in a Sentence
verb
British English
- The data must be corrected to sea-level pressure.
- Forecasters will sea-level pressure the readings from mountain stations.
American English
- The model sea-level pressures all surface observations.
- You need to sea-level pressure that value for the chart.
adverb
British English
- The pressure was reported sea-levelly. (Highly unnatural, not used)
- N/A
American English
- N/A
adjective
British English
- The sea-level pressure value is crucial.
- Look at the sea-level pressure gradient on the map.
American English
- The sea-level pressure reading was 1013 hPa.
- A sea-level pressure analysis revealed the storm's intensity.
Usage
Meaning in Context
Business
Rare, except in specific industries like shipping, aviation, or agricultural commodities trading where weather is a direct factor.
Academic
Common in geography, environmental science, physics, and climatology textbooks and research papers.
Everyday
Very rare. Might be heard in detailed weather forecasts, especially for sailing or aviation.
Technical
Core term in meteorology, oceanography, and aviation for weather maps (isobaric charts) and reports.
Vocabulary
Synonyms of “sea-level pressure”
Strong
Neutral
Weak
Vocabulary
Antonyms of “sea-level pressure”
Watch out
Common Mistakes When Using “sea-level pressure”
- Using 'sea-level pressure' to mean the actual pressure measured at the coast. (It's a calculation, not a location-based measurement).
- Confusing it with 'tidal pressure' or 'water pressure at sea level'.
FAQ
Frequently Asked Questions
No. It is a calculated value. If you are at the beach at sea level, your measured pressure might be close, but official sea-level pressure is a standardized adjustment applied to all weather stations.
Pilots set their altimeters based on the local sea-level pressure setting. An incorrect setting leads to an inaccurate altitude reading, which is a critical safety issue.
The global average is approximately 1013.25 hectopascals (hPa), also known as 1 atmosphere (atm) or 29.92 inches of mercury (inHg).
In precise technical use, MSLP often refers to the average over a short period or a specific calculation method. In general forecasting, the terms are frequently used interchangeably to mean the adjusted pressure value.
The atmospheric pressure at mean sea level, used as a standard reference point in meteorology.
Sea-level pressure is usually technical / scientific in register.
Sea-level pressure: in British English it is pronounced /ˈsiː levəl ˈpreʃə/, and in American English it is pronounced /ˈsiː levəl ˈpreʃər/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “None. It is a technical term.”
Learning
Memory Aids
Mnemonic
Think of a map that flattens all the mountains and valleys to show the air pressure as if everywhere were at the same level as the sea.
Conceptual Metaphor
PRESSURE IS A FORCE (exerted by the weight of the air); STANDARDIZATION IS FLATTENING (reducing varied elevations to a common plane).
Practice
Quiz
What is the primary purpose of using 'sea-level pressure' instead of 'station pressure' on a weather map?