General Circulation of the Atmosphere: Overview

The atmospheric general circulation connotes the motion of the atmosphere, as viewed from a global, long-term perspective. This term is usually applied to the seasonally-varying, climatological-mean circulation, including the statistical properties of the variability of the circulation on day-to-day, week-to-week, and month-to-month time scales, but it also encompasses year-to-year variability and long-term variations associated with climate change. A unifying concept in studies of the general circulation are the so-called balance requirements for the conservation of angular momentum, total energy, and the mass of water vapor and other trace substances. Also of interest are the processes that contribute to the generation and dissipation of the kinetic energy, the exchange of kinetic energy between the zonally averaged circulation and the longitudinally varying 'eddies,' the exchange of air between troposphere and stratosphere, and the long range transport of trace substances.