# dobson

/ˈdɑbsən/ (US) · CEFR C2 · Noun

Source: https://englishreference.com/word/dobson
Updated: 2026-08-15

## Definition

a unit used to measure how much ozone is in the atmosphere above a specific place.

For teachers: a unit of measurement for the total amount of a trace gas, typically ozone, in a vertical column of the atmosphere. One unit represents a layer of gas that would be 0.01 millimetres thick at standard temperature and pressure.

## Examples

- Scientists use the dobson unit to track the ozone hole.
- The thickness of the ozone layer is typically around 300 to 500 dobson units in most parts of the world.
- Researchers observed a significant drop in dobson units over the Antarctic region, signaling a seasonal thinning of the protective ozone layer that requires continuous satellite monitoring.

## Usage notes

- Almost exclusively used in the compound phrase 'dobson unit'; often capitalised as 'Dobson' because it is named after G.M.B. Dobson.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.