Brewer Dobson circulation

Brewer-Dobson circulation is a model of atmospheric circulation, proposed by Alan Brewer in 1949 and Gordon Dobson in 1956, which attempts to explain why tropical air has less ozone than polar air, even though the tropical stratosphere is where most atmospheric ozone is produced. It is a simple circulation model that posits the existence of a slow current in the winter hemisphere which redistributes air from the tropics to the extratropics. The Brewer-Dobson circulation is driven by atmospheric waves and may be speeding up due to climate change.