Parameter Tree:
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC PRESSURE > ANTICYCLONES/CYCLONES

Definition:
An anticyclone is a dome of air that exerts relatively high
atmospheric pressure compared with the surrounding air at a given level. A
cyclone is a weather system characterised by relatively low surface air
pressure at a given level and a closed cyclonic wind circulation. 


Reference:
Glossary of Weather and Climate, American Meteorological Society, 1996.