User:John R. Brews/Coriolis force: Difference between revisions
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where ''f'' = {{nowrap|2''ω'' sin''φ''}} is the Coriolis parameter. Consequently, the wind takes an apparent direction deflected to the right of the pressure gradient in the northern latitudes, and to the left in the southern latitudes. The Coriolis parameter is a maximum at the poles, zero at the equator and flips sign as one crosses form the northern to southern hemispheres, as indicated in the figure. | where ''f'' = {{nowrap|2''ω'' sin''φ''}} is the Coriolis parameter. Consequently, the wind takes an apparent direction deflected to the right of the pressure gradient in the northern latitudes, and to the left in the southern latitudes. The Coriolis parameter is a maximum at the poles, zero at the equator and flips sign as one crosses form the northern to southern hemispheres, as indicated in the figure. | ||
One consequence is that a low pressure region that sucks air into it, as shown in the figure, results in a counterclockwise flow of winds in the northern hemisphere because of the Coriolis force. | One consequence is that a low pressure region that sucks air into it, as shown in the figure, results in a counterclockwise flow of winds in the northern hemisphere (called a cyclone) because of the Coriolis force.<ref name = Todd> | ||
For further discussion see {{cite book |title=An Introduction to Physical Science |author=James T. Shipman, Jerry D. Wilson, Aaron Todd |url=http://books.google.com/books?id=1LvMLoaN0HQC&pg=PA557 |pages=pp. 557 ''ff'' |year=2007 |edition = 12th ed |isbn=0618935967 |publisher=Cengage Learning}} | |||
</ref> | |||
==Notes== | ==Notes== | ||
Revision as of 16:58, 5 March 2011
Meteorology
A pressure gradient in the atmosphere is equalized by driving a wind along the pressure gradient. However, from the viewpoint of meteorology, the motion is observed most naturally within the reference frame of a rotating Earth. As pointed out just above and in the figure to the left, in the Earth's reference frame any motion is affected by a Coriolis force, as given by:
where f = 2ω sinφ is the Coriolis parameter. Consequently, the wind takes an apparent direction deflected to the right of the pressure gradient in the northern latitudes, and to the left in the southern latitudes. The Coriolis parameter is a maximum at the poles, zero at the equator and flips sign as one crosses form the northern to southern hemispheres, as indicated in the figure.
One consequence is that a low pressure region that sucks air into it, as shown in the figure, results in a counterclockwise flow of winds in the northern hemisphere (called a cyclone) because of the Coriolis force.[1]
Notes
- ↑ For further discussion see James T. Shipman, Jerry D. Wilson, Aaron Todd (2007). An Introduction to Physical Science, 12th ed. Cengage Learning, pp. 557 ff. ISBN 0618935967.
Contributed by myself in June 2008, for example, here here, added Limerick