general circulation

1. (Also called planetary circulation.) In its broadest sense, the complete statistical description of large scale atmospheric motions.

These statistics are generated from the ensemble of daily data and include not only the temporal and spatial mean flows (e.g. zonal westerlies and easterlies) but also all other mean properties of the atmosphere that are linked to these flows (e.g., semipermanent waves and meridional cells) that together form the general circulation. The general circulation also includes higher-order statistics that measure the spatial and temporal variability of the atmosphere necessary to understand the large-scale temporal and spatial mean state of the atmosphere (e.g., seasonal changes and the effects of transient cyclones).
Compare planetary circulation.

1. 
   See primary circulation.
   Grotjahn, R. 1993. Global Atmospheric Circulations: Observations and Theories. 3–4, 160–161.
   Holton, J. R. 1992. An Introduction to Dynamic Meteorology. 3d ed., . 310–312.
   Peixoto, J. P., and A. H. Oort 1992. Physics of Climate. 8–26.

1. Regular markings on an instrument used to allow the reading of the measured quantity or setting.

1. The study of the physics, chemistry, and dynamics of the earth's atmosphere, including the related effects at the air–earth boundary over both land and the oceans. Fundamental topics include the composition, structure, and motion of the atmosphere. The goals ascribed to meteorology are the complete understanding and accurate prediction of atmospheric phenomena.

The slowly varying aspects of the atmosphere–hydrosphere–land surface system.