Frictional torque

From Glossary of Meteorology
Revision as of 18:05, 26 January 2012 by imported>Perlwikibot (Created page with " {{TermHeader}} {{TermSearch}} <div class="termentry"> <div class="term"> == frictional torque == </div> <div class="definition"><div class="short_definition">The [[tor...")
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

frictional torque

The torque exerted by the force of friction.

In meteorology, this term usually refers to the effect of surface friction. The eastward component of the frictional torque is of primary interest because, together with the eastward component of the mountain torque, it constitutes the only significant mechanism by which the atmosphere can gain or lose absolute angular momentum about the earth's axis. This torque may be expressed by the integral
where a is the earth's radius, φ is the latitude, τx is the eastward component of the frictional force per unit area, and ds is an areal element of the earth's surface. The frictional torque serves to impart the earth's angular momentum to the air, thus decreasing or increasing the (relative) wind speed.

Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact 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.