Difference between revisions of "Coriolis force"

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<div class="definition"><div class="short_definition">(<br/>''Also called'' compound centrifugal force, deflecting force.) An [[apparent force]] on  moving [[particles]] in a noninertial [[coordinate system]], that is, the [[Coriolis acceleration]] as seen  in this (relative) system.</div><br/> <div class="paragraph">Such a force is required if Newton's laws are to be applied in this system. In meteorology the  Coriolis force per unit mass arises solely from the earth's rotation, and is equal to &minus;2'''&#x003a9;''' &times; '''u''', where  '''&#x003a9;''' is the [[angular velocity of the earth]] and '''u''' is the (relative) [[velocity]] of the particle. Thus the  Coriolis force acts as a deflecting force, normal to the velocity, to the right of the motion in the  Northern Hemisphere and to the left in the Southern Hemisphere. It cannot alter the speed of  the particle. The three components toward east, north, and [[zenith]] are, respectively, 2&#x003a9; (''v'' sin&#x003c6;  &minus; ''w'' cos&#x003c6;), &minus;2&#x003a9;''u'' sin&#x003c6;, and 2&#x003a9;''u'' cos&#x003c6;, where ''u'','' v'', ''w'' are the component velocities and &#x003c6; the  latitude. Since the Coriolis force is in effect proportional to the speed, its importance in any given  atmospheric motion may be judged from the representative speed and duration of the motion. <br/>''See''  [[inertial force]].</div><br/> </div><div class="reference">Gill, A. E. 1982. Atmosphere&ndash;Ocean Dynamics. Academic Press, . 72&ndash;74. </div><br/> <div class="reference">Holton, J. R. 1992. An Introduction to Dynamic Meteorology. 3d edition, Academic Press, . 31&ndash;38. </div><br/>  
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<div class="definition"><div class="short_definition">(''Also called'' compound centrifugal force, deflecting force.) An [[apparent force]] on  moving [[particles]] in a noninertial [[coordinate system]], that is, the [[Coriolis acceleration]] as seen  in this (relative) system.</div><br/> <div class="paragraph">Such a force is required if Newton's laws are to be applied in this system. In meteorology the  Coriolis force per unit mass arises solely from the earth's rotation, and is equal to -2'''&#x003a9;''' &times; '''u''', where  '''&#x003a9;''' is the [[angular velocity of the earth]] and '''u''' is the (relative) [[velocity]] of the particle. Thus the  Coriolis force acts as a deflecting force, normal to the velocity, to the right of the motion in the  Northern Hemisphere and to the left in the Southern Hemisphere. It cannot alter the speed of  the particle. The three components toward east, north, and [[zenith]] are, respectively, 2&#x003a9; (''v'' sin&#x003c6;  - ''w'' cos&#x003c6;), -2&#x003a9;''u'' sin&#x003c6;, and 2&#x003a9;''u'' cos&#x003c6;, where ''u'','' v'', ''w'' are the component velocities and &#x003c6; the  latitude. Since the Coriolis force is in effect proportional to the speed, its importance in any given  atmospheric motion may be judged from the representative speed and duration of the motion. <br/>''See''  [[inertial force]].</div><br/> </div><div class="reference">Gill, A. E. 1982. Atmosphere&ndash;Ocean Dynamics. Academic Press, . 72&ndash;74. </div><br/> <div class="reference">Holton, J. R. 1992. An Introduction to Dynamic Meteorology. 3d edition, Academic Press, . 31&ndash;38. </div><br/>  
 
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Latest revision as of 14:58, 20 February 2012



Coriolis force

(Also called compound centrifugal force, deflecting force.) An apparent force on moving particles in a noninertial coordinate system, that is, the Coriolis acceleration as seen in this (relative) system.

Such a force is required if Newton's laws are to be applied in this system. In meteorology the Coriolis force per unit mass arises solely from the earth's rotation, and is equal to -2Ω × u, where Ω is the angular velocity of the earth and u is the (relative) velocity of the particle. Thus the Coriolis force acts as a deflecting force, normal to the velocity, to the right of the motion in the Northern Hemisphere and to the left in the Southern Hemisphere. It cannot alter the speed of the particle. The three components toward east, north, and zenith are, respectively, 2Ω (v sinφ - w cosφ), -2Ωu sinφ, and 2Ωu cosφ, where u, v, w are the component velocities and φ the latitude. Since the Coriolis force is in effect proportional to the speed, its importance in any given atmospheric motion may be judged from the representative speed and duration of the motion.
See inertial force.

Gill, A. E. 1982. Atmosphere–Ocean Dynamics. Academic Press, . 72–74.

Holton, J. R. 1992. An Introduction to Dynamic Meteorology. 3d edition, Academic Press, . 31–38.