Brunt-väisälä frequency

From Glossary of Meteorology
Revision as of 11:40, 15 December 2014 by imported>Liss45 (→‎Brunt–Väisälä frequency)



Brunt–Väisälä frequency

The frequency N at which a displaced air parcel will oscillate when displaced vertically within a statically stable environment.

It is given as
Brunt V final.png
where g = 9.8 m s–1 is gravitational acceleration, θυa is the ambient virtual potential temperature, and ∂θυa/∂z is the vertical gradient of the ambient virtual potential temperature. Units are radians per second, although this is usually abbreviated as s–1. This frequency is not defined in statically unstable air and is zero in statically neutral air. The frequency of internal gravity waves in the atmosphere cannot exceed the local Brunt–Väisälä frequency. This frequency is also sometimes used as a measure of the stability within a statically stable environment.


Reference:
Stull, R. B. 1995. Meteorology Today for Scientists and Engineers. 385 pp.


term edited 15 Dec 2014

Copyright 2024 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.