Jet Stream

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Jet Stream flowing in a semi-continuous band around the globe from west to east, it is caused by the changes in air temperature where the cold polar air moving towards the equator meets the warmer equatorial air moving polarward. It is marked by a concentration of isotherms and strong vertical shear.
Jet Stream flowing in a semi-continuous band around the globe from west to east, it is caused by the changes in air temperature where the cold polar air moving towards the equator meets the warmer equatorial air moving polarward. It is marked by a concentration of isotherms and strong vertical shear.
Jet Stream is an area of strong winds that are concentrated in a relatively narrow band in the upper troposphere of the middle latitudes and subtropical regions of the Northern and Southern Hemispheres.
Jet Stream is an area of strong winds that are concentrated in a relatively narrow band in the upper troposphere of the middle latitudes and subtropical regions of the Northern and Southern Hemispheres.

An area of strong winds that are concentrated in a relatively narrow band in the upper troposphere of the middle latitudes and subtropical regions of the Northern and Southern Hemispheres.

Flowing in a semi-continuous band around the globe from west to east, it is caused by the changes in air temperature where the cold polar air moving towards the equator meets the warmer equatorial air moving polarward. It is marked by a concentration of isotherms and strong vertical shear.

Jet streams are caused by a combination of a planet's rotation on its axis and atmospheric heating (by solar radiation and, on some planets other than Earth, internal heat). The Coriolis effect describes how a planet's surface and atmosphere rotate fastest relative to each other at the planet's equator while virtually not rotating at all at the poles.

While this speed difference generally has very little effect on a planet's surface, it plays an important role in atmospheric air currents because air at higher levels of the atmosphere, especially near the equator, must travel very fast to keep up with the planet's rotation.

Thus there is a tendency for air at higher levels of the atmosphere to "slip" and fall behind the speed of the air below.

This results in a pressure buildup behind the "slipped" air, and so some air will have to catch up by moving in the same general direction as the planet's rotation (west to east on Earth); however, this air does not follow a simple pattern but instead is also influenced by its temperature and water content compared to that of surrounding air regions.

In essence, instead of the atmosphere moving along with the planet consistently, parts of the atmosphere travel faster than others via jet streams.

Jet streams form near boundaries of adjacent air masses with significant differences in temperature, such as the polar region and the warmer air towards the equator.


[edit] Reference

  • Wikipedia Jet Steam [1]

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