Subtropical jet stream

Definition

The subtropical jet stream is a fast-flowing air current located in the upper levels of the atmosphere, typically between 20 to 30 degrees latitude in both hemispheres. This jet stream plays a significant role in influencing weather patterns and climate by separating tropical air from polar air and affecting the formation and movement of storm systems.

5 Must Know Facts For Your Next Test

1. The subtropical jet stream is generally located around 30,000 to 40,000 feet above sea level, where it can reach speeds of up to 150 miles per hour.
2. It typically flows west to east and can have significant impacts on the weather patterns in the regions below it, including influencing precipitation and temperature variations.
3. Seasonal shifts in the position of the subtropical jet stream occur, moving northward during the summer months and southward in winter, which affects storm tracks and weather systems.
4. The subtropical jet stream is associated with the boundaries of the Hadley cell circulation, which helps to transport warm air from the tropics towards higher latitudes.
5. Variations in the strength and position of the subtropical jet stream can lead to extreme weather events, such as droughts or heavy rainfall, by altering typical atmospheric circulation patterns.

Review Questions

• How does the subtropical jet stream influence weather patterns in regions located beneath it?
  • The subtropical jet stream has a profound effect on weather patterns below it by acting as a boundary between tropical and polar air masses. Its position can dictate the movement of storm systems and can either enhance or suppress precipitation in certain areas. For instance, when the subtropical jet dips southward, it can bring cooler temperatures and increased rain to regions that typically experience dry conditions.
• Compare and contrast the subtropical jet stream with the polar jet stream in terms of their locations and effects on weather.
  • The subtropical jet stream is located between 20 to 30 degrees latitude, while the polar jet stream is found at higher latitudes around 30 to 60 degrees. The subtropical jet tends to influence weather primarily in tropical and sub-tropical regions by separating warm tropical air from cooler air masses. In contrast, the polar jet stream impacts mid-latitude weather more directly by driving storm systems and contributing to temperature fluctuations due to its proximity to cold polar air.
• Evaluate the implications of changes in the subtropical jet stream on global climate patterns and extreme weather events.
  • Changes in the subtropical jet stream can have far-reaching implications for global climate patterns and extreme weather events. For example, if the jet stream becomes more erratic or shifts its position due to climate change, it could lead to prolonged periods of drought or excessive rainfall in certain regions. This variability can affect agricultural productivity, water supply, and contribute to natural disasters like floods or heatwaves. Understanding these changes is critical for predicting future climate scenarios and preparing for potential impacts on human activities and ecosystems.

Related terms

polar jet stream: The polar jet stream is another major upper-atmospheric wind pattern found at higher latitudes, typically between 30 to 60 degrees latitude, that significantly influences mid-latitude weather systems.

Rossby waves: Rossby waves are large-scale meanders in high-altitude winds that help transport energy and contribute to the development of weather systems across the globe.

Hadley cell: The Hadley cell is a large-scale atmospheric circulation pattern that occurs in the tropics, contributing to the development of the subtropical jet stream and influencing global weather and climate.