Zonal and meridional flow
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Zonal and meridional flowaredirectionsandregionsoffluid flowon aglobe. Zonal flowfollows a pattern alonglatitudinallines,latitudinal circlesor in the west–east direction.[1] Meridional flowfollows a pattern from north to south, or from south to north, along the Earth'slongitudelines,longitudinal circles(meridian) or in the north–south direction.[2] These terms are often used in theatmosphericandearth sciencesto describe global phenomena, such as "meridional wind", or "zonal average temperature".
In the context of physics, zonal flow connotes a tendency offluxto conform to a pattern parallel to theequatorof a sphere. Inmeteorologicalterm regardingatmospheric circulation,zonal flow brings a temperature contrast along the Earth's longitude.Extratropical cyclonesin zonal flows tend to be weaker, moving faster and producing relatively little impact on local weather.
Extratropical cyclonesin meridional flows tend to be stronger and move slower. This pattern is responsible for most instances ofextreme weather,as not only are storms stronger in this type of flow regime, but temperatures can reach extremes as well, producingheat wavesandcold wavesdepending on theequator-ward or poleward direction of the flow.
Forvector fields(such aswind velocity), the zonal component (orx-coordinate) is denoted asu,while the meridional component (ory-coordinate) is denoted asv.
In plasma physicsZonal flow (plasma)meanspoloidal,which is the opposite from the meaning in planetary atmospheres and weather/climate studies.
See also
[edit]Notes
[edit]- ^"Zonal".Glossary of Meteorology.American Meteorological Society.Retrieved12 January2018.
- ^"Meridional".Glossary of Meteorology.American Meteorological Society.Retrieved12 January2018.