Center of Action

center of action

[′sen·tər əv ′ak·shən] (meteorology) A semipermanent high or low atmospheric pressure system at the surface of the earth; fluctuations in the intensity, position, orientation, shape, or size of such a center are associated with widespread weather changes.

Center of Action

 

an area of high or low atmospheric pressure on charts of the global distribution of surface pressure. Centers of action are a statistical result of the prevalence of anticyclones or cyclones in a particular region. A distinction is made between semipermanent and seasonal centers of action; in Russian, the semipermanent centers are called permanent (postoiannye, or permanentnye) centers. The semipermanent centers of action are the equatorial trough, subtropical highs, the subpolar low-pressure belts, and arctic highs. The seasonal centers of action are continental highs and continental low-pressure areas.