1. A movement of atmospheric masses caused by the gravitational attraction of the sun and moon and by daily solar heating; amplitudes are minute except in the upper atmosphere.
2. The rhythmic, periodic oscillation of the earth's atmosphere because of the gravitational effects of the earth, sun, and moon and to the absorption of radiation by the atmosphere.
3. A tidal movement of the atmosphere resembling an ocean tide but caused principally by diurnal temperature changes.

Both the sun and moon produce atmospheric tides, and there also exist both gravitational tides (gravitational attraction of the sun or moon) and thermal tides (differential heating of the atmosphere by the sun).