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🪐intro to astronomy review

Jet Stream

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

A jet stream is a narrow, fast-moving current of air that flows high in the Earth's atmosphere, typically at an altitude between 7-12 kilometers. These winds play a crucial role in the global circulation patterns that shape the Earth's weather and climate.

5 Must Know Facts For Your Next Test

  1. Jet streams are typically located near the tropopause, the boundary between the troposphere and the stratosphere.
  2. The position and strength of the jet streams are influenced by the temperature difference between the equator and the poles.
  3. Jet streams play a crucial role in the global circulation of air masses, which in turn affects weather patterns and climate.
  4. Disturbances in the jet stream, such as Rossby waves, can lead to the formation of high- and low-pressure systems, influencing weather conditions.
  5. The position and strength of the jet stream can change over time, contributing to long-term climate variability and the occurrence of extreme weather events.

Review Questions

  • Explain the role of the jet stream in the Earth's atmospheric circulation.
    • The jet stream is a key component of the Earth's atmospheric circulation system. It acts as a fast-moving, high-altitude river of air that helps drive the movement of air masses and weather patterns around the globe. The jet stream's position and strength are influenced by the temperature difference between the equator and the poles, which in turn affects the overall circulation of air masses and the resulting weather conditions. Disturbances in the jet stream, such as Rossby waves, can lead to the formation of high- and low-pressure systems, influencing weather patterns on a continental scale.
  • Describe how the jet stream is related to the tropopause and its significance in the Earth's atmosphere.
    • The jet stream is typically located near the tropopause, which is the boundary layer between the troposphere and the stratosphere. This positioning is significant because the tropopause marks a transition in the vertical temperature structure of the atmosphere, with the troposphere generally cooling with height and the stratosphere warming. The jet stream's location near the tropopause is influenced by this temperature difference, as the jet stream forms in response to the temperature gradient between the equator and the poles. The jet stream's position and behavior can also have a significant impact on the exchange of air and other atmospheric properties between the troposphere and the stratosphere, which is important for understanding the Earth's overall atmospheric circulation and climate system.
  • Analyze how changes in the jet stream can contribute to long-term climate variability and the occurrence of extreme weather events.
    • The position and strength of the jet stream can undergo changes over time, which can have significant implications for long-term climate variability and the occurrence of extreme weather events. Shifts in the jet stream's location, such as a poleward or equatorward movement, can alter the distribution of air masses and weather patterns on a continental scale. This can lead to changes in temperature, precipitation, and the frequency and intensity of weather events in different regions. Additionally, disturbances in the jet stream, such as the formation of Rossby waves, can disrupt the normal flow of air masses and contribute to the development of high-pressure systems, low-pressure systems, and other extreme weather phenomena. Understanding the complex interactions between the jet stream, atmospheric circulation, and climate is crucial for predicting and adapting to the impacts of long-term climate variability and extreme weather events.