Subtropical jet stream

Definition

The subtropical jet stream is a fast-flowing ribbon of air located at approximately 30 degrees latitude in both hemispheres, characterized by westerly winds that can reach speeds of up to 200 mph. This jet stream plays a vital role in the global atmospheric circulation and influences weather patterns, including the development of storms and precipitation in various regions.

5 Must Know Facts For Your Next Test

1. The subtropical jet stream forms primarily due to temperature differences between the warm tropical air and cooler polar air, creating a strong pressure gradient.
2. It typically strengthens during the winter months when the temperature contrast is more pronounced, leading to more pronounced and faster winds.
3. This jet stream is located at higher altitudes, generally between 10,000 to 15,000 meters (around 33,000 to 49,000 feet), above the Earth's surface.
4. The position and strength of the subtropical jet stream can significantly influence tropical storm development and can steer them towards land or open ocean.
5. Variability in the subtropical jet stream can lead to prolonged weather patterns, such as droughts or excessive rainfall, depending on its location relative to land masses.

Review Questions

• How does the subtropical jet stream influence weather patterns in both hemispheres?
  • The subtropical jet stream influences weather patterns by guiding the movement of weather systems across regions. It affects storm paths, precipitation distribution, and can enhance or suppress development of tropical storms based on its position. When it shifts north or south, it can lead to significant changes in temperature and precipitation in areas beneath it.
• Discuss how the subtropical jet stream interacts with the Hadley Cell circulation and its effects on climate.
  • The subtropical jet stream is directly influenced by the Hadley Cell circulation, which transports warm air from the equator toward higher latitudes. As this warm air rises and cools, it contributes to the formation of high-pressure systems that anchor the subtropical jet stream. This interaction leads to arid climates in regions like deserts near 30 degrees latitude as descending air suppresses precipitation.
• Evaluate the impact of climate change on the behavior and characteristics of the subtropical jet stream.
  • Climate change is expected to alter the characteristics of the subtropical jet stream by affecting its strength and position. Warming temperatures may weaken the temperature gradients that drive this jet stream, potentially leading to slower wind speeds and more meandering paths. This could result in prolonged weather events, such as extended droughts or increased rainfall, significantly impacting agriculture and water resources in affected regions.

Related terms

Polar Jet Stream: A fast-moving air current found at higher latitudes, typically around 50-60 degrees, that significantly affects mid-latitude weather patterns.

Hadley Cell: A large-scale atmospheric circulation pattern that occurs between the equator and about 30 degrees latitude, contributing to the formation of the subtropical jet stream.

Rossby Waves: Large-scale meanders in high-altitude winds that influence weather patterns and are closely related to the positions of the jet streams.