Description

Brewer-Dobson circulation refers to the global atmospheric circulation pattern of tropical tropospheric air rising into the stratosphere and then moving poleward as it descends. The circulation pattern explains observations of ozone and water vapour distribution and has been accelerating in recent decades, likely due to climate change.

Brewer-Dobson circulation is driven by planetary scale atmospheric waves, namely Rossby waves.

Global impacts

Because it moves air into and out of the stratosphere, Brewer-Dobson circulation determines tropical tropopause temperatures and stratospheric water vapour. Brewer-Dobson circulation directly impacts the distribution and abundance of stratospheric ozone by moving it from the tropics towards the poles. This transport helps to explain why tropical air has less ozone than polar air, even though the tropical stratosphere is where most atmospheric ozone is produced.

Brewer-Dobson circulation of ozone in the atmosphere [source: Wikicommons. Author: NASA]