(meteorology) The difference in pressure between the Azores High and the Icelandic Low, which changes periodically and controls the strength of the Westerlies. Usually abbreviated NAO.

plural of North Atlantic Oscillation

A quasiperiodic oscillation of the equatorial zonal wind between easterlies and westerlies in the tropical stratosphere

plural of quasi-biennial oscillation

A test to identify, evaluate and locate partial discharge faults in cable insulation and accessories.