Jet streams

Definition

Jet streams are fast-flowing, narrow air currents in the atmosphere, typically found at altitudes of about 10 kilometers (6 miles) above sea level. They play a crucial role in shaping weather patterns and atmospheric circulation by influencing the movement of air masses and storm systems across the globe.

5 Must Know Facts For Your Next Test

1. Jet streams are typically located between 30° and 60° latitude in both hemispheres and are influenced by the temperature differences between polar and tropical air masses.
2. The most notable jet stream is the polar jet stream, which flows from west to east and is strongest during winter months when temperature contrasts are greatest.
3. Jet streams can shift their position and intensity due to seasonal changes, affecting weather patterns such as storms, droughts, and heatwaves.
4. They play a significant role in aviation, as pilots often use jet streams to save fuel and reduce travel time by flying with the flow of these high-altitude winds.
5. Changes in jet stream patterns can be linked to climate change, leading to more extreme weather events as they influence how air masses interact across the globe.

Review Questions

• How do jet streams influence weather patterns in different regions around the world?
  • Jet streams greatly influence weather patterns by guiding the movement of air masses and storm systems. They can steer cold polar air southward or warm tropical air northward, affecting temperatures and precipitation in various regions. Additionally, the position and strength of jet streams can lead to the development or dissipation of storms, thus playing a key role in determining local weather conditions.
• Discuss how the polar jet stream differs from the subtropical jet stream in terms of location, characteristics, and impact on global weather systems.
  • The polar jet stream is located at higher latitudes, typically between 30° and 60° latitude, while the subtropical jet stream is found closer to 30° latitude. The polar jet is usually stronger and more variable than the subtropical jet due to greater temperature differences between polar and tropical air masses. This difference in characteristics affects their impacts on global weather systems; for instance, the polar jet often influences mid-latitude storms more significantly than the subtropical jet.
• Evaluate the relationship between jet streams and climate change, particularly focusing on how altered jet stream patterns can affect extreme weather events.
  • Climate change can lead to alterations in jet stream patterns, primarily due to changes in temperature gradients between equatorial and polar regions. These shifts can result in a more meandering jet stream, which may cause prolonged periods of extreme weather, such as heatwaves or cold snaps. As the dynamics of the atmosphere change with rising global temperatures, understanding this relationship becomes crucial for predicting future weather events and managing their impacts on society.

Related terms

tropopause: The boundary between the troposphere and the stratosphere, where jet streams are commonly located.

trade winds: Prevailing winds that blow from east to west in the tropics, contributing to global wind patterns and affecting the positioning of jet streams.

Rossby waves: Large-scale undulations in the jet stream that help determine the movement of weather systems and can lead to significant weather events.