Jet stream

Definition

The jet stream is a fast-flowing air current found in the atmosphere, typically located at high altitudes around 10 kilometers (6 miles) above the Earth’s surface. It plays a crucial role in shaping weather patterns and influencing global atmospheric circulation by acting as a boundary between different air masses, particularly between polar and warmer air. Its position and strength can significantly affect the climate of regions below, as it guides storm systems and influences temperature distribution.

5 Must Know Facts For Your Next Test

1. The jet stream is typically located at the boundary between the troposphere and the stratosphere, where temperature gradients are steepest.
2. There are generally two main jet streams: the polar jet stream and the subtropical jet stream, each having distinct characteristics and effects on weather.
3. Jet streams can shift seasonally, being stronger and more defined during winter months due to larger temperature differences between polar and equatorial air.
4. The position of the jet stream can influence major weather events like storms, droughts, and heatwaves by directing the movement of air masses.
5. Changes in the jet stream's behavior due to climate change may lead to more extreme weather patterns and shifts in climate zones.

Review Questions

• How does the jet stream influence local weather patterns and what mechanisms are involved in this process?
  • The jet stream influences local weather patterns by steering storm systems and controlling temperature distribution. Its fast-moving air currents can cause troughs and ridges that lead to changes in pressure systems. When the jet stream dips southward, it can bring cold polar air into warmer regions, leading to significant temperature drops or snowstorms. Conversely, when it rises northward, warmer air can dominate, potentially resulting in heatwaves.
• Evaluate the impact of the Coriolis Effect on the jet stream's movement and its implications for global weather patterns.
  • The Coriolis Effect impacts the jet stream by causing it to curve rather than move in a straight line due to the Earth’s rotation. This curvature affects how air masses interact and contributes to the development of cyclones and anticyclones. As a result, understanding this effect helps meteorologists predict weather patterns and assess how changes in the jet stream may influence climatic conditions across different regions.
• Analyze how changes in the jet stream associated with climate change might affect future weather extremes worldwide.
  • Changes in the jet stream linked to climate change could result in altered weather extremes globally by making it more erratic and slower-moving. This could lead to prolonged periods of extreme temperatures, whether heat or cold, as well as increased frequency of severe weather events like hurricanes or prolonged droughts. The disruption of typical patterns may challenge existing agricultural practices and infrastructure as regions become more susceptible to unpredictable climate variability.

Related terms

Trade Winds: Consistent winds that blow from east to west in the tropics, forming part of the global atmospheric circulation pattern.

Coriolis Effect:

The apparent deflection of moving objects, such as air currents, caused by the Earth's rotation, influencing the direction of the jet stream.

Troughs and Ridges: Features of the jet stream's undulating path; troughs are areas of lower pressure, while ridges are areas of higher pressure, both affecting weather patterns.