Westerlies

Definition

Westerlies are prevailing winds that blow from the west to the east in the mid-latitudes, typically between 30 and 60 degrees latitude in both hemispheres. These winds play a crucial role in global circulation patterns, influencing weather systems and ocean currents. The westerlies are essential for transporting moisture and heat across regions, affecting climate and weather phenomena in various areas.

5 Must Know Facts For Your Next Test

1. The westerlies generally blow from the southwest in the Northern Hemisphere and from the northwest in the Southern Hemisphere.
2. These winds are responsible for carrying storm systems across the mid-latitudes, influencing weather patterns like cyclones and anticyclones.
3. The strength of the westerlies can vary seasonally, being stronger in winter due to increased temperature contrasts between polar and tropical regions.
4. Areas located under the influence of westerlies typically experience milder climates with more precipitation compared to regions dominated by trade winds.
5. The interaction between westerlies and ocean currents creates significant upwelling zones that support rich marine ecosystems along coastlines.

Review Questions

• How do westerlies influence weather systems in mid-latitude regions?
  • Westerlies play a vital role in shaping weather systems in mid-latitude regions by transporting moist air masses and storm systems from west to east. These prevailing winds interact with other atmospheric features, such as high-pressure systems and jet streams, leading to the development of cyclones and anticyclones. As a result, areas under the influence of westerlies typically experience variable weather conditions, including rainstorms and shifting temperatures.
• Discuss the relationship between westerlies and ocean currents in terms of climate impact.
  • Westerlies significantly influence ocean currents by driving surface water movement in the ocean. The winds push water toward the poles, contributing to major current systems like the North Atlantic Drift and the Humboldt Current. This interaction affects regional climates by redistributing heat and moisture, leading to milder temperatures along coastlines and influencing precipitation patterns, thus playing a crucial role in maintaining ecological balance.
• Evaluate how changes in the strength of westerlies might affect global climate patterns.
  • Changes in the strength of westerlies can have profound impacts on global climate patterns. A strengthening of these winds may lead to more intense storm systems and altered precipitation patterns in mid-latitude regions. Conversely, a weakening could cause stagnant weather conditions, contributing to droughts or excessive rainfall. Understanding these dynamics is essential for predicting future climate scenarios and their potential effects on ecosystems and human activities worldwide.

Related terms

Trade Winds: The trade winds are easterly winds that dominate the tropics, blowing from east to west and contributing to the movement of weather systems.

Jet Stream: The jet stream is a fast-flowing air current found in the atmosphere at high altitudes, often associated with the westerlies and influencing weather patterns.

Coriolis Effect: The Coriolis effect is the deflection of moving objects, including air masses, due to Earth's rotation, which significantly influences wind patterns, including the westerlies.