A surface of constant atmospheric pressure which is related to a specific pressure datum, 1013.2 hPa (1013.2 mb), and is separated from other such surfaces by specific pressure intervals.
Source FAA Pilot/Controller Glossary · checked 2026-08-25
A surface of constant atmospheric pressure which is related to a specific pressure datum, 1013.2 hPa (1013.2 mb), and is separated from other such surfaces by specific pressure intervals.
Source FAA Pilot/Controller Glossary · checked 2026-08-25