Subtropical highs

Definition

Subtropical highs are large areas of high pressure located around 30 degrees latitude in both hemispheres, characterized by descending air that creates stable and dry conditions. These systems are crucial for understanding global circulation patterns as they influence weather patterns and the distribution of deserts, often leading to the development of trade winds and the positioning of major ocean currents.

5 Must Know Facts For Your Next Test

1. Subtropical highs form as a result of the Hadley Cell circulation, where warm air rises near the equator and cools as it moves toward the poles, leading to high pressure in the subtropics.
2. These high-pressure systems contribute to the formation of some of the world's major deserts, such as the Sahara and the Australian Desert, due to their dry and stable conditions.
3. Subtropical highs are dynamic and can vary in strength and position depending on seasonal changes and climate phenomena like El Niño.
4. The trade winds that arise from subtropical highs are critical for maritime navigation and climate patterns across oceans, significantly affecting weather systems globally.
5. Understanding subtropical highs is important for predicting weather patterns and climate changes, as their behavior can impact precipitation patterns in both tropical and mid-latitude regions.

Review Questions

• How do subtropical highs influence global wind patterns and ocean currents?
  • Subtropical highs play a vital role in shaping global wind patterns by creating the trade winds that blow from east to west in the tropics. These high-pressure systems promote stable atmospheric conditions that lead to consistent wind patterns. Additionally, they affect ocean currents by driving surface water movement towards the equator, thereby influencing marine ecosystems and climate across various regions.
• Discuss the relationship between subtropical highs and desert formation around the globe.
  • Subtropical highs are closely linked to desert formation due to their ability to create dry conditions. As these high-pressure systems dominate areas around 30 degrees latitude, they cause air to descend and warm, leading to decreased humidity and precipitation. This process contributes to arid regions such as the Sahara Desert in Africa and the Great Victoria Desert in Australia, illustrating how these atmospheric features directly affect local climates.
• Evaluate how variations in subtropical high-pressure systems can impact climate change scenarios and weather extremes.
  • Variations in subtropical high-pressure systems can significantly impact climate change scenarios by altering precipitation patterns and intensifying droughts or flooding events. Changes in strength or position of these highs can lead to shifts in trade winds and ocean currents, influencing global climate systems. For example, a stronger subtropical high may prolong drought conditions in certain regions while enhancing rainfall in others, thereby affecting agricultural productivity, water resources, and overall climate resilience.

Related terms

Hadley Cell:

A tropical atmospheric circulation that features rising air near the equator, creating a band of low pressure, while air descends in the subtropics to form high pressure.

Trade Winds: Persistent east-to-west winds that occur in the tropics, caused by the subtropical highs and the Coriolis effect, essential for oceanic circulation.

Desertification: The process by which fertile land becomes desert, often as a result of drought, deforestation, or inappropriate agriculture, closely linked to the presence of subtropical highs.