Subtropical highs

Definition

Subtropical highs are areas of high atmospheric pressure located approximately 30 degrees north and south of the equator. These pressure systems are characterized by descending air, leading to dry and stable weather conditions. Subtropical highs play a crucial role in global atmospheric circulation patterns by influencing trade winds, ocean currents, and the distribution of climates across the globe.

5 Must Know Facts For Your Next Test

1. Subtropical highs are commonly associated with major desert regions like the Sahara and the Arabian Desert, where dry conditions prevail due to sinking air.
2. These high-pressure systems are typically more pronounced during summer months, leading to increased heat and dryness in the surrounding areas.
3. The subtropical highs are integral to the formation of trade winds, which are crucial for oceanic circulation and weather patterns.
4. These areas of high pressure contribute to the development of semi-arid climates as they suppress precipitation through stable atmospheric conditions.
5. The position and strength of subtropical highs can shift with seasonal changes, impacting regional climate patterns and weather systems.

Review Questions

• How do subtropical highs influence global wind patterns, particularly the trade winds?
  • Subtropical highs exert a significant influence on global wind patterns by creating areas of high pressure that lead to the formation of trade winds. The descending air associated with subtropical highs causes winds to flow outwards towards lower pressure zones near the equator. This results in the northeast trade winds in the Northern Hemisphere and southeast trade winds in the Southern Hemisphere, driving ocean currents and impacting climate across various regions.
• Discuss the relationship between subtropical highs and desert formation around the world.
  • Subtropical highs play a critical role in desert formation by creating dry conditions. The sinking air associated with these high-pressure areas inhibits cloud formation and precipitation, resulting in arid environments. Regions such as the Sahara Desert and parts of Australia are located under the influence of subtropical highs, demonstrating how these systems can lead to extensive desertification in certain latitudes.
• Evaluate how changes in climate patterns could affect the stability and position of subtropical highs and their implications on global weather systems.
  • Changes in climate patterns can significantly affect the stability and positioning of subtropical highs, which may alter regional weather conditions. For instance, increased global temperatures could strengthen these high-pressure systems, causing them to expand further poleward or shift their positions. This shift could lead to altered precipitation patterns, exacerbating droughts in some areas while increasing rainfall in others, ultimately impacting agriculture, water resources, and ecosystems worldwide.

Related terms

Hadley Cell:

A large-scale atmospheric circulation pattern that occurs between the equator and about 30 degrees latitude, where warm air rises at the equator and sinks in the subtropics.

Trade Winds: Winds that blow predominantly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere, resulting from the Earth's rotation and subtropical high-pressure areas.

Desert Climates: Climates characterized by low precipitation and high evaporation rates, often found in regions influenced by subtropical highs.