Qa-Qz

 

QBO

Acronym for Quasi-Biennial Oscillation.

 

Quasi-Biennial Oscillation

The alternation of easterly and westerly winds in the equatorial stratosphere with an interval between successive corresponding maxima of 20 to 36 months. The regimes start at about 30 km and propagate downwards at about one kilometer per month.

 

quasi-geostrophic approximation

A set of filtered equations to the equations of motion governing atmospheric or oceanic flow, the chief of which is the vorticity equation. In this, the horizontal wind is replaced by the geostrophic wind in the term representing the vorticity but not in the term representing the divergence.

 

quantum meter

An instrument used to measure PAR.

 

Quaternary

The second of two periods of the Cenozoic era, lasting from 1.8 to 0.0 Ma, i.e. the present period. It follows the Tertiary period and is comprised of the Pleistocene (1.8 Ma-8000 Ya) and Holocene (8000 Ya-present) epochs. It was originally designated an era rather than a period, and the epochs periods, and is still used as such occasionally.